推荐|21天学通C++读书笔记（二十三：自适应容器：栈和队列）

21天学通C++读书笔记（二十三：自适应容器：栈和队列）

23-11-18 01:40

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blog.csdn.net

1. 栈和队列的行为特征

栈和队列与数组或 list 极其相似，但对插入、访问和删除元素的方式有一定的限制。可将元素插入到什么位置以及可从什么位置删除元素决定了容器的行为特征

1.1 栈

栈是 LIFO（后进先出）系统，只能从栈顶插入或删除元素
泛型 STL 容器 std::stack 模拟了栈的这种行为

1.2 队列

队列是 FIFO（先进先出）系统，元素被插入到队尾，最先插入的元素最先删除
泛型 STL 容器 std::queue 模拟了队列的这种行为

2. 使用STL stack 类

2.1 实例化stack

template<
    class elementType,
    class Container = deque<Type>
> class stack;
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参数 elementType 是stack 存储的对象类型
第二个模板参数 Container 是 stack 使用的默认底层容器实现类
stack 默认在内部使用 std::deque 来存储数据，但可指定使用 vector 或 list 来存储数据

#include 
#include 

int main () {
    using namespace std;

    stack<int> numsInStack;
    stack<double> dblsInStack;
    // 将第二个模板参数（stack 在内部使用的集合类）指定为 vector
    stack<double, vector<double> > doublesStackedInVec;
    // 使用一个stack 对象的拷贝来创建另一个stack对象
    stack<int> numsInStackCopy(numsInStack);
    
    return 0;
}
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2.2 stack 的成员函数

stack 改变了另一种容器（如 deque、list 或 vector）的行为，通过限制元素插入或删除的方式实现其功能，从而提供严格遵守栈机制的行为特征
std::stack 的成员函数

函数	描述
push()	在栈顶插入元素 numsInStack.push (25);
pop()	删除栈顶的元素 numsInStack.pop ( );
empty()	检查栈是否为空并返回一个布尔值 if (numsInStack.empty ( )) DoSomething ( );
size()	返回栈中的元素数 size_t numElements = numsInStack.size ( );
top()	获得指向栈顶元素的引用 cout << "Element at the top = " << numsInStack.top ( );

2.3 使用 push() 和 pop() 在栈顶插入和删除元素

#include 
#include 
	
int main () {
    using namespace std;
    stack<int> numsInStack;
    cout << "Pushing {25, 10, -1, 5} on stack in that order:" << endl;
    numsInStack.push(25);
    numsInStack.push(10);
    numsInStack.push(-1);
    numsInStack.push(5);
    
    cout << "Stack contains " << numsInStack.size() << " elements" << endl;
    while (numsInStack.size() != 0) {
        cout << "Popping topmost element: " << numsInStack.top() << endl;
        numsInStack.pop(); // pop: removes topmost element
    }
    
    if (numsInStack.empty()) { // true: due to previous pop()s
        cout << "Popping all elements empties stack!" << endl;
    }
    return 0;
}
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3. 使用STL queue 类

STL queue 是一个模板类，要使用它，必须包含头文件 queue
queue 是一个泛型类，只允许在末尾插入元素以及从开头删除元素
queue 不允许访问中间的元素，但可以访问开头和末尾的元素

3.1 实例化queue

template <
    class elementType,
    class Container = deque<Type>
> class queue;
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其中 elementType 是 queue 对象包含的元素的类型
Container 是 std::queue 用于存储其数据的集合类型，可将该模板参数设置为 std::list、vector 或 deque，默认为 deque

#include 
#include 

int main () {
    using namespace std;
    queue<int> numsInQ;
    queue<double> dblsInQ;
    queue<double, list<double> > dblsInQInList;
    queue<int> copyQ(numsInQ);
    
    return 0;
}
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3.2 queue 的成员函数

函数	描述
push()	在队尾（即最后一个位置）插入一个元素
pop()	将队首（即最开始位置）的元素删除
front()	返回指向队首元素的引用
back()	返回指向队尾元素（即最后插入的元素）的引用
empty()	检查队列是否为空并返回一个布尔值
size()	返回队列中的元素数

STL queue 没有提供 begin() 和 end() 等函数，这是有意为之的，旨在只允许对 queue 执行符合队列行为特征的操作

3.3 使用 push() 在队尾插入以及使用 pop() 从队首删除

#include 
#include 

int main () {
    using namespace std;
    queue<int> numsInQ;
    
    cout << "Inserting {10, 5, -1, 20} into queue" << endl;
    numsInQ.push(10);
    numsInQ.push(5);  // elements are inserted at the end
    numsInQ.push(-1);
    numsInQ.push(20);
    
    cout << "Queue contains " << numsInQ.size() << " elements" << endl;
    cout << "Element at front: " << numsInQ.front() << endl;
    cout << "Element at back: " << numsInQ.back() << endl;
    
    while (numsInQ.size() != 0) {
        cout << "Deleting element: " << numsInQ.front() << endl;
        numsInQ.pop();  // removes element at front
    }
    
    if (numsInQ.empty()) {
        cout << "The queue is now empty!" << endl;
    }
    return 0;
}
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4. 使用STL 优先级队列

STL priority_queue 是一个模板类，要使用它，也必须包含头文件 queue
priority_queue 与 queue 的不同之处在于，包含最大值（或二元谓词认为是最大值）的元素位于队首，且只能在队首执行操作

4.1 实例化priority_queue 类

template <
    class elementType,
    class Container=vector<Type>,
    class Compare=less<typename Container::value_type>
> class priority_queue;
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其中 elementType 是一个模板参数，指定了优先级队列将包含的元素的类型
第二个模板参数指定 priority_queue 在内部将使用哪个集合类来存储数据
第三个参数让程序员能够指定一个二元谓词，以帮助队列判断哪个元素应位于队首,。如果没有指定二元谓词，priority_queue 类将默认使用 std::less，它使用运算符 < 比较对象

#include 
#include 

int main () {
    using namespace std;
    
    // Priority queue of int sorted using std::less <> (default)
    priority_queue<int> numsInPrioQ;
    priority_queue<double> dblsInPrioQ;
    
    // A priority queue of integers sorted using std::greater <>
    priority_queue<int, deque<int>, greater<int> > numsInDescendingQ;
    priority_queue<int> copyQ(numsInPrioQ);
    
    return 0;
}
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4.2 priority_queue 的成员函数

函数	描述
push()	在优先级队列中插入一个元素
pop()	删除队首元素，即最大的元素
top()	返回指向队列中最大元素（即队首元素）的引用
empty()	检查优先级队列是否为空并返回一个布尔值
size()	返回优先级队列中的元素个数

4.3 使用push()在priority_queue末尾插入以及使用pop()在priority_queue开头删除

#include 
#include 

int main () {
    using namespace std;
    
    priority_queue<int> numsInPrioQ;
    cout << "Inserting {10, 5, -1, 20} into the priority_queue" << endl;
    numsInPrioQ.push(10);
    numsInPrioQ.push(5);  
    numsInPrioQ.push(-1);
    numsInPrioQ.push(20);
    
    cout << "Deleting the " << numsInPrioQ.size() << " elements" << endl;
    while (!numsInPrioQ.empty()) {
        cout << "Deleting topmost element: " << numsInPrioQ.top() << endl;
        numsInPrioQ.pop();
    }
    return 0;
}
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通过使用谓词将值最小的元素放在 priority_queue 开头

#include 
#include 
#include 

int main () {
    using namespace std;

    // greater 表示内置类型从大到小排序，less 表示内置类型从小到大排序
    // greater 谓词导致包含的整数最小的元素被认为是最大的，因此放在队首
    priority_queue<int, vector<int>, greater<int> > numsInPrioQ;
    
    cout << "Inserting {10, 5, -1, 20} into the priority queue" << endl;
    numsInPrioQ.push(10);
    numsInPrioQ.push(5);
    numsInPrioQ.push(-1);
    numsInPrioQ.push(20);
    
    cout << "Deleting " << numsInPrioQ.size() << " elements" << endl;
    while (!numsInPrioQ.empty ()) {
        cout << "Deleting topmost element " << numsInPrioQ.top () << endl;
        numsInPrioQ.pop ();
    }
    return 0;
}
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Q&A

能否对队列中的所有元素进行迭代？
- 队列不支持迭代器，只能访问队尾的元素
STL 算法能否用于自适应容器？
- STL 算法使用迭代器。由于 stack 和 queue 类都没有提供标记范围两端的迭代器，因此无法将 STL 算法用于这些容器

id="article_content" class="article_content clearfix"> id="content_views" class="htmledit_views">

在之前工作（使用Tauri + Leptos开发带系统托盘桌面应用-CSDN博客）的基础上，继续尝试对本地Sqlite数据库进行读、写、删除操作，开发环境还是VS Code+Rust-analyzer。

最终程序界面如下：

主要参考文章：Building a todo app in Tauri with SQLite and sqlx

1. 创建项目

还是用create-tauri-app来创建一个新项目，并安装sqlx-cli。

 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">[package] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">name = "acid-index" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line">version = "0.1.0" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line">description = "A Tauri App" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line">authors = ["you"] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line">edition = "2021" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line"># See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="9"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="10"> class="hljs-ln-code"> class="hljs-ln-line">[lib] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="11"> class="hljs-ln-code"> class="hljs-ln-line"># The `_lib` suffix may seem redundant but it is necessary class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="12"> class="hljs-ln-code"> class="hljs-ln-line"># to make the lib name unique and wouldn't conflict with the bin name. class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="13"> class="hljs-ln-code"> class="hljs-ln-line"># This seems to be only an issue on Windows, see https://github.com/rust-lang/cargo/issues/8519 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="14"> class="hljs-ln-code"> class="hljs-ln-line">name = "acid_index_lib" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="15"> class="hljs-ln-code"> class="hljs-ln-line">crate-type = ["staticlib", "cdylib", "rlib"] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="16"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="17"> class="hljs-ln-code"> class="hljs-ln-line">[build-dependencies] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="18"> class="hljs-ln-code"> class="hljs-ln-line">tauri-build = { version = "2", features = [] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="19"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="20"> class="hljs-ln-code"> class="hljs-ln-line">[dependencies] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="21"> class="hljs-ln-code"> class="hljs-ln-line">tauri = { version = "2", features = ["tray-icon"] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="22"> class="hljs-ln-code"> class="hljs-ln-line">tauri-plugin-opener = "2" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="23"> class="hljs-ln-code"> class="hljs-ln-line">serde = { version = "1", features = ["derive"] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="24"> class="hljs-ln-code"> class="hljs-ln-line">serde_json = "1" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="25"> class="hljs-ln-code"> class="hljs-ln-line">#tauri-plugin-sql = {version = "2", features = ["sqlite"] } # or "postgres", or "mysql" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="26"> class="hljs-ln-code"> class="hljs-ln-line">sqlx = { version = "0.8.2", features = ["sqlite", "runtime-tokio"] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="27"> class="hljs-ln-code"> class="hljs-ln-line">tokio = { version ="1", features = ["full"] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="28"> class="hljs-ln-code"> class="hljs-ln-line">futures = "0.3.31" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="29"> class="hljs-ln-code"> class="hljs-ln-line">log = "0.4.22" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="30"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="31"> class="hljs-ln-code"> class="hljs-ln-line">#for win7 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="32"> class="hljs-ln-code"> class="hljs-ln-line">#tauri-plugin-notification = { version = "2", features = [ "windows7-compat" ] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="33"> class="hljs-ln-code"> class="hljs-ln-line"> class="hide-preCode-box">

class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">cd src-tauri class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">sqlx migrate add create_users_table class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">-- Add migration script here class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">CREATE TABLE IF NOT EXISTS users ( class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line"> id INTEGER PRIMARY KEY AUTOINCREMENT, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line"> username TEXT NOT NULL, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line"> email TEXT class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line"> ); class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">use futures::TryStreamExt; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">use sqlx::{migrate::MigrateDatabase, prelude::FromRow, sqlite::SqlitePoolOptions, Pool, Sqlite}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line">use tauri::{App, Manager}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line">type Db = Pool; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line">struct DbState { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line"> db: Db, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="9"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="10"> class="hljs-ln-code"> class="hljs-ln-line">async fn setup_db(app: &App) -> Db { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="11"> class="hljs-ln-code"> class="hljs-ln-line"> let mut path = app.path().app_data_dir().expect("获取程序数据文件夹路径失败！"); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="12"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="13"> class="hljs-ln-code"> class="hljs-ln-line"> match std::fs::create_dir_all(path.clone()) { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="14"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(_) => {} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="15"> class="hljs-ln-code"> class="hljs-ln-line"> Err(err) => { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="16"> class="hljs-ln-code"> class="hljs-ln-line"> panic!("创建文件夹错误：{}", err); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="17"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="18"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="19"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="20"> class="hljs-ln-code"> class="hljs-ln-line"> //C:\Users\\AppData\Roaming\com.mynewapp.app\db.sqlite class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="21"> class="hljs-ln-code"> class="hljs-ln-line"> path.push("db.sqlite"); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="22"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="23"> class="hljs-ln-code"> class="hljs-ln-line"> Sqlite::create_database( class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="24"> class="hljs-ln-code"> class="hljs-ln-line"> format!("sqlite:{}", path.to_str().expect("文件夹路径不能为空！")).as_str(), class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="25"> class="hljs-ln-code"> class="hljs-ln-line"> ) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="26"> class="hljs-ln-code"> class="hljs-ln-line"> .await class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="27"> class="hljs-ln-code"> class="hljs-ln-line"> .expect("创建数据库失败！"); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="28"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="29"> class="hljs-ln-code"> class="hljs-ln-line"> let db = SqlitePoolOptions::new() class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="30"> class="hljs-ln-code"> class="hljs-ln-line"> .connect(path.to_str().unwrap()) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="31"> class="hljs-ln-code"> class="hljs-ln-line"> .await class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="32"> class="hljs-ln-code"> class="hljs-ln-line"> .unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="33"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="34"> class="hljs-ln-code"> class="hljs-ln-line"> //创建迁移文件位于./migrations/文件夹下 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="35"> class="hljs-ln-code"> class="hljs-ln-line"> //cd src-tauri class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="36"> class="hljs-ln-code"> class="hljs-ln-line"> //sqlx migrate add create_users_table class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="37"> class="hljs-ln-code"> class="hljs-ln-line"> sqlx::migrate!("./migrations/").run(&db).await.unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="38"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="39"> class="hljs-ln-code"> class="hljs-ln-line"> db class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="40"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="41"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="42"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="43"> class="hljs-ln-code"> class="hljs-ln-line">// Learn more about Tauri commands at https://tauri.app/develop/calling-rust/ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="44"> class="hljs-ln-code"> class="hljs-ln-line">#[tauri::command] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="45"> class="hljs-ln-code"> class="hljs-ln-line">fn greet(name: &str) -> String { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="46"> class="hljs-ln-code"> class="hljs-ln-line"> format!("你好， {}！Rust向你问候了！", name) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="47"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="48"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="49"> class="hljs-ln-code"> class="hljs-ln-line">use serde::{Deserialize, Serialize}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="50"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Debug, Serialize, Deserialize, FromRow)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="51"> class="hljs-ln-code"> class="hljs-ln-line">struct User { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="52"> class="hljs-ln-code"> class="hljs-ln-line"> id: u16, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="53"> class="hljs-ln-code"> class="hljs-ln-line"> username: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="54"> class="hljs-ln-code"> class="hljs-ln-line"> email: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="55"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="56"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="57"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Debug, Serialize, Deserialize, FromRow)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="58"> class="hljs-ln-code"> class="hljs-ln-line">struct UserId { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="59"> class="hljs-ln-code"> class="hljs-ln-line"> id: u16, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="60"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="61"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="62"> class="hljs-ln-code"> class="hljs-ln-line">#[tauri::command] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="63"> class="hljs-ln-code"> class="hljs-ln-line">async fn get_db_value(state: tauri::State<'_, DbState>, window: tauri::Window) -> Result<String, String> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="64"> class="hljs-ln-code"> class="hljs-ln-line"> let db = &state.db; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="65"> class="hljs-ln-code"> class="hljs-ln-line"> let query_result:Vec = sqlx::query_as::<_, User>( //查询数据以特定的格式输出 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="66"> class="hljs-ln-code"> class="hljs-ln-line"> "SELECT * FROM users" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="67"> class="hljs-ln-code"> class="hljs-ln-line"> ) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="68"> class="hljs-ln-code"> class="hljs-ln-line"> .fetch(db) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="69"> class="hljs-ln-code"> class="hljs-ln-line"> .try_collect() class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="70"> class="hljs-ln-code"> class="hljs-ln-line"> .await.unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="71"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="72"> class="hljs-ln-code"> class="hljs-ln-line"> let mut div_content = String::new(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="73"> class="hljs-ln-code"> class="hljs-ln-line"> for user in query_result.iter(){ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="74"> class="hljs-ln-code"> class="hljs-ln-line"> div_content += &format!(r#"ID：{}，姓名：{}，邮箱：{} "#, user.id, user.username, user.email); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="75"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="76"> class="hljs-ln-code"> class="hljs-ln-line"> // 获取当前窗口 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="77"> class="hljs-ln-code"> class="hljs-ln-line"> let current_window = window.get_webview_window("main").unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="78"> class="hljs-ln-code"> class="hljs-ln-line"> let script = &format!("document.getElementById('db-item').innerHTML = '{}';",div_content); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="79"> class="hljs-ln-code"> class="hljs-ln-line"> current_window.eval(script).unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="80"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="81"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(String::from("数据库读取成功！")) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="82"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="83"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="84"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="85"> class="hljs-ln-code"> class="hljs-ln-line">//use tauri::Error; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="86"> class="hljs-ln-code"> class="hljs-ln-line">#[tauri::command] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="87"> class="hljs-ln-code"> class="hljs-ln-line">async fn insert_db_item(state: tauri::State<'_, DbState>, username: &str, email: Option<&str>) -> Result<String, String> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="88"> class="hljs-ln-code"> class="hljs-ln-line"> let db = &state.db; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="89"> class="hljs-ln-code"> class="hljs-ln-line"> email.unwrap_or("not set yet"); //email类型为Option<&str>，其结果为None或者Some(&str) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="90"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="91"> class="hljs-ln-code"> class="hljs-ln-line"> sqlx::query("INSERT INTO users (username, email) VALUES (?1, ?2)") class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="92"> class="hljs-ln-code"> class="hljs-ln-line"> .bind(username) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="93"> class="hljs-ln-code"> class="hljs-ln-line"> .bind(email) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="94"> class="hljs-ln-code"> class="hljs-ln-line"> .execute(db) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="95"> class="hljs-ln-code"> class="hljs-ln-line"> .await class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="96"> class="hljs-ln-code"> class="hljs-ln-line"> .map_err(|e| format!("数据库插入项目错误: {}", e))?; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="97"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="98"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(String::from("插入数据成功！")) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="99"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="100"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="101"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="102"> class="hljs-ln-code"> class="hljs-ln-line">#[tauri::command] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="103"> class="hljs-ln-code"> class="hljs-ln-line">async fn del_last_user(state: tauri::State<'_, DbState>) -> Result<String, String> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="104"> class="hljs-ln-code"> class="hljs-ln-line"> let db = &state.db; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="105"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="106"> class="hljs-ln-code"> class="hljs-ln-line"> let last_id:UserId = sqlx::query_as::<_,UserId>("SELECT id FROM users ORDER BY id DESC LIMIT 1") class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="107"> class="hljs-ln-code"> class="hljs-ln-line"> .fetch_one(db) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="108"> class="hljs-ln-code"> class="hljs-ln-line"> .await class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="109"> class="hljs-ln-code"> class="hljs-ln-line"> .unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="110"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="111"> class="hljs-ln-code"> class="hljs-ln-line"> sqlx::query("DELETE FROM users WHERE id = ?1") class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="112"> class="hljs-ln-code"> class="hljs-ln-line"> .bind(last_id.id) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="113"> class="hljs-ln-code"> class="hljs-ln-line"> .execute(db) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="114"> class="hljs-ln-code"> class="hljs-ln-line"> .await class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="115"> class="hljs-ln-code"> class="hljs-ln-line"> .map_err(|e| format!("could not delete last user: {}", e))?; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="116"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="117"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(String::from("最后一条数据删除成功！")) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="118"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="119"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="120"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="121"> class="hljs-ln-code"> class="hljs-ln-line">mod tray; //导入tray.rs模块 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="122"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="123"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="124"> class="hljs-ln-code"> class="hljs-ln-line">#[cfg_attr(mobile, tauri::mobile_entry_point)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="125"> class="hljs-ln-code"> class="hljs-ln-line">pub fn run() { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="126"> class="hljs-ln-code"> class="hljs-ln-line"> tauri::Builder::default() class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="127"> class="hljs-ln-code"> class="hljs-ln-line"> .plugin(tauri_plugin_opener::init()) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="128"> class="hljs-ln-code"> class="hljs-ln-line"> .invoke_handler(tauri::generate_handler![greet, get_db_value, insert_db_item, update_user, del_last_user]) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="129"> class="hljs-ln-code"> class="hljs-ln-line"> .setup(|app| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="130"> class="hljs-ln-code"> class="hljs-ln-line"> #[cfg(all(desktop))] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="131"> class="hljs-ln-code"> class="hljs-ln-line"> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="132"> class="hljs-ln-code"> class="hljs-ln-line"> let handle = app.handle(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="133"> class="hljs-ln-code"> class="hljs-ln-line"> tray::create_tray(handle)?; //设置app系统托盘 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="134"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="135"> class="hljs-ln-code"> class="hljs-ln-line"> tauri::async_runtime::block_on(async move { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="136"> class="hljs-ln-code"> class="hljs-ln-line"> let db = setup_db(&app).await; //setup_db(&app:&mut App)返回读写的数据库对象 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="137"> class="hljs-ln-code"> class="hljs-ln-line"> app.manage(DbState { db }); //通过app.manage(DbState{db})把数据库对象传递给state:tauri::State<'_, DbState> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="138"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="139"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(()) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="140"> class="hljs-ln-code"> class="hljs-ln-line"> }) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="141"> class="hljs-ln-code"> class="hljs-ln-line"> .run(tauri::generate_context!()) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="142"> class="hljs-ln-code"> class="hljs-ln-line"> .expect("运行Tauri程序的时候出错！"); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="143"> class="hljs-ln-code"> class="hljs-ln-line">} class="hide-preCode-box">

class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">#[tauri::command] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">async fn get_db_value(state: tauri::State<'_, DbState>) -> Result<Vec, String> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line"> let db = &state.db; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line"> let query_result:Vec = sqlx::query_as::<_, User>( //查询到的数据以特定的格式输出 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line"> "SELECT * FROM users" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line"> ) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line"> .fetch(db) class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line"> .try_collect() class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="9"> class="hljs-ln-code"> class="hljs-ln-line"> .await.unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="10"> class="hljs-ln-code"> class="hljs-ln-line"> Ok(query_result) //查询结果传递给前端 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="11"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Serialize, Deserialize)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">struct User { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line"> id: u16, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line"> username: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line"> email: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="9"> class="hljs-ln-code"> class="hljs-ln-line">#[component] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="10"> class="hljs-ln-code"> class="hljs-ln-line">pub fn App(initial_value:i32) -> impl IntoView { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="11"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="12"> class="hljs-ln-code"> class="hljs-ln-line">...... class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="13"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="14"> class="hljs-ln-code"> class="hljs-ln-line"> let (div_content, set_div_content) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="15"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="16"> class="hljs-ln-code"> class="hljs-ln-line"> let get_db_item = move |ev: SubmitEvent| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="17"> class="hljs-ln-code"> class="hljs-ln-line"> ev.prevent_default(); //类似javascript中的Event.preventDefault() class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="18"> class="hljs-ln-code"> class="hljs-ln-line"> spawn_local(async move { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="19"> class="hljs-ln-code"> class="hljs-ln-line"> let user_js = invoke_without_args("send_db_item").await; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="20"> class="hljs-ln-code"> class="hljs-ln-line"> let user_vec: Vec = serde_wasm_bindgen::from_value(user_js).map_err(|_| JsValue::from("Deserialization error")).unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="21"> class="hljs-ln-code"> class="hljs-ln-line"> let mut receive_msg = String::from("读取数据库ID序列为：["); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="22"> class="hljs-ln-code"> class="hljs-ln-line"> let mut inner_content = String::new(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="23"> class="hljs-ln-code"> class="hljs-ln-line"> for user in user_vec{ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="24"> class="hljs-ln-code"> class="hljs-ln-line"> receive_msg += &format!("{}, ", user.id); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="25"> class="hljs-ln-code"> class="hljs-ln-line"> inner_content += &format!(r###" ID：{}，姓名：{}，邮箱：{} "###, user.id, user.id, user.username, user.email); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="26"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="27"> class="hljs-ln-code"> class="hljs-ln-line"> receive_msg += "]"; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="28"> class="hljs-ln-code"> class="hljs-ln-line"> set_insert_msg.set(receive_msg); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="29"> class="hljs-ln-code"> class="hljs-ln-line"> set_div_content.set(inner_content); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="30"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="31"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="32"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="33"> class="hljs-ln-code"> class="hljs-ln-line"> view! { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="34"> class="hljs-ln-code"> class="hljs-ln-line"> ...... class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="35"> class="hljs-ln-code"> class="hljs-ln-line"> //使用inner_html修改div内容 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="36"> class="hljs-ln-code"> class="hljs-ln-line"> "db-window" id="db-item" inner_html=div_content /> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="37"> class="hljs-ln-code"> class="hljs-ln-line"> ...... class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="38"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hide-preCode-box">

class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">#[wasm_bindgen] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">extern "C" { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line">+ #[wasm_bindgen(js_namespace = ["window", "__TAURI__", "core"], js_name = invoke)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line">+ async fn invoke_without_args(cmd: &str) -> JsValue; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line"> #[wasm_bindgen(js_namespace = ["window", "__TAURI__", "core"])] //Tauri API 将会存储在 window.__TAURI__ 变量中，并通过 wasm-bindgen 导入。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line"> async fn invoke(cmd: &str, args: JsValue) -> JsValue; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-button signin active" data-title="登录复制" data-report-click="{"spm":"1001.2101.3001.4334"}" onclick="hljs.signin(event)">

class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="1"> class="hljs-ln-code"> class="hljs-ln-line">use leptos::task::spawn_local; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="2"> class="hljs-ln-code"> class="hljs-ln-line">use leptos::{ev::SubmitEvent, prelude::*}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="3"> class="hljs-ln-code"> class="hljs-ln-line">use serde::{Deserialize, Serialize}; //#derive(serialize, Deserialize)用于请求响应传递参数的序列化 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="4"> class="hljs-ln-code"> class="hljs-ln-line">use wasm_bindgen::prelude::*; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="5"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="6"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="7"> class="hljs-ln-code"> class="hljs-ln-line">//‌WASM（WebAssembly）是一种低级字节码格式，可以从C、C++、Rust等高级语言编译而来，旨在在Web端实现接近原生的执行效率‌‌ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="8"> class="hljs-ln-code"> class="hljs-ln-line">//wasm 并不是传统意义上汇编语言(Assembly),而是一种中间编译的字节码,可以在浏览器上运行非 JavaScript 编写的代码 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="9"> class="hljs-ln-code"> class="hljs-ln-line">//wasm-bindgen主要目的是实现Rust与现有JavaScript环境的无缝集成‌，自动生成必要的绑定和胶水代码，确保Rust函数和JavaScript之间平滑通信 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="10"> class="hljs-ln-code"> class="hljs-ln-line">#[wasm_bindgen] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="11"> class="hljs-ln-code"> class="hljs-ln-line">extern "C" { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="12"> class="hljs-ln-code"> class="hljs-ln-line"> #[wasm_bindgen(js_namespace = ["window", "__TAURI__", "core"], js_name = invoke)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="13"> class="hljs-ln-code"> class="hljs-ln-line"> async fn invoke_without_args(cmd: &str) -> JsValue; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="14"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="15"> class="hljs-ln-code"> class="hljs-ln-line"> #[wasm_bindgen(js_namespace = ["window", "__TAURI__", "core"])] //Tauri API 将会存储在 window.__TAURI__ 变量中，并通过 wasm-bindgen 导入。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="16"> class="hljs-ln-code"> class="hljs-ln-line"> async fn invoke(cmd: &str, args: JsValue) -> JsValue; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="17"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="18"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="19"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="20"> class="hljs-ln-code"> class="hljs-ln-line">//derive是一个编译器指令，在类型定义（如结构体或枚举）上添加#[derive(...)]让编译器为一些特性提供基本的实现， class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="21"> class="hljs-ln-code"> class="hljs-ln-line">//...表示要为其提供基本实现的特性列表。#[derive(Serialize, Deserialize)]，可以轻松地为结构体实现序列化和反序列化功能。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="22"> class="hljs-ln-code"> class="hljs-ln-line">//要在Rust中使用序列化和反序列化，首先需要在Cargo.toml文件中引入serde库 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="23"> class="hljs-ln-code"> class="hljs-ln-line">//serde = { version = "1.0", features = ["derive"] } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="24"> class="hljs-ln-code"> class="hljs-ln-line">//serde_json = "1.0" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="25"> class="hljs-ln-code"> class="hljs-ln-line">//序列化后的变量作为函数invoke(cmd, args: JsValue)的参数，JsValue为序列化格式 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="26"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Serialize, Deserialize)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="27"> class="hljs-ln-code"> class="hljs-ln-line">struct GreetArgs<'a> { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="28"> class="hljs-ln-code"> class="hljs-ln-line"> name: &'a str, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="29"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="30"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="31"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Serialize, Deserialize)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="32"> class="hljs-ln-code"> class="hljs-ln-line">struct InsertArgs<'a> { //生命周期标识符 'a 用于帮助编译器检查引用的有效性，避免悬垂引用和使用已被释放的内存。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="33"> class="hljs-ln-code"> class="hljs-ln-line"> username: &'a str, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="34"> class="hljs-ln-code"> class="hljs-ln-line"> email: &'a str, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="35"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="36"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="37"> class="hljs-ln-code"> class="hljs-ln-line">#[derive(Serialize, Deserialize)] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="38"> class="hljs-ln-code"> class="hljs-ln-line">struct User { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="39"> class="hljs-ln-code"> class="hljs-ln-line"> id: u16, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="40"> class="hljs-ln-code"> class="hljs-ln-line"> username: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="41"> class="hljs-ln-code"> class="hljs-ln-line"> email: String, class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="42"> class="hljs-ln-code"> class="hljs-ln-line">} class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="43"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="44"> class="hljs-ln-code"> class="hljs-ln-line">//Component是一个重要的概念，它通常指的是项目中的一部分代码或功能模块。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="45"> class="hljs-ln-code"> class="hljs-ln-line">#[component] class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="46"> class="hljs-ln-code"> class="hljs-ln-line">pub fn App(initial_value:i32) -> impl IntoView { //函数返回IntoView类型，即返回view!宏，函数名App()也是主程序view!宏中的组件名(component name)。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="47"> class="hljs-ln-code"> class="hljs-ln-line"> let (name, set_name) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="48"> class="hljs-ln-code"> class="hljs-ln-line"> let (greet_msg, set_greet_msg) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="49"> class="hljs-ln-code"> class="hljs-ln-line"> let (value, set_value) = signal(initial_value); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="50"> class="hljs-ln-code"> class="hljs-ln-line"> let (username, set_username) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="51"> class="hljs-ln-code"> class="hljs-ln-line"> let (email, set_email) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="52"> class="hljs-ln-code"> class="hljs-ln-line"> let (insert_msg, set_insert_msg) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="53"> class="hljs-ln-code"> class="hljs-ln-line"> //let (fetch_msg, set_fetch_msg) = signal(String::new()); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="54"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="55"> class="hljs-ln-code"> class="hljs-ln-line"> let update_name = move |ev| { //将闭包传递给按钮组件的onclick参数，鼠标点击触发事件，更新之前创建signal中的值。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="56"> class="hljs-ln-code"> class="hljs-ln-line"> let v = event_target_value(&ev); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="57"> class="hljs-ln-code"> class="hljs-ln-line"> set_name.set(v); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="58"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="59"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="60"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="61"> class="hljs-ln-code"> class="hljs-ln-line"> let get_db_item = move |ev: SubmitEvent| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="62"> class="hljs-ln-code"> class="hljs-ln-line"> ev.prevent_default(); //类似javascript中的Event.preventDefault(),处理字段非常有用 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="63"> class="hljs-ln-code"> class="hljs-ln-line"> spawn_local(async move { //使用Leptos的spawn_local创建一个本地线程(local_thread)Future, 提供一个异步move闭包。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="64"> class="hljs-ln-code"> class="hljs-ln-line"> let new_msg = invoke_without_args("get_db_value").await.as_string().unwrap(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="65"> class="hljs-ln-code"> class="hljs-ln-line"> set_insert_msg.set(new_msg); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="66"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="67"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="68"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="69"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="70"> class="hljs-ln-code"> class="hljs-ln-line"> let greet = move |ev: SubmitEvent| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="71"> class="hljs-ln-code"> class="hljs-ln-line"> ev.prevent_default(); //类似javascript中的Event.preventDefault(),处理字段非常有用 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="72"> class="hljs-ln-code"> class="hljs-ln-line"> spawn_local(async move { //使用Leptos的spawn_local创建一个本地线程(local_thread)Future, 提供一个异步move闭包。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="73"> class="hljs-ln-code"> class="hljs-ln-line"> let name = name.get_untracked(); //防止通常由Leptos signal产生的反应式绑定，因此即使值发生变化，Leptos也不会尝试更新闭包。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="74"> class="hljs-ln-code"> class="hljs-ln-line"> if name.is_empty() { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="75"> class="hljs-ln-code"> class="hljs-ln-line"> return; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="76"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="77"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="78"> class="hljs-ln-code"> class="hljs-ln-line"> let args = serde_wasm_bindgen::to_value(&GreetArgs { name: &name }).unwrap(); //参数序列化 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="79"> class="hljs-ln-code"> class="hljs-ln-line"> // Learn more about Tauri commands at https://tauri.app/develop/calling-rust/ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="80"> class="hljs-ln-code"> class="hljs-ln-line"> let new_msg = invoke("greet", args).await.as_string().unwrap(); //使用invoke调用greet命令，greet类似于API class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="81"> class="hljs-ln-code"> class="hljs-ln-line"> set_greet_msg.set(new_msg); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="82"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="83"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="84"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="85"> class="hljs-ln-code"> class="hljs-ln-line"> let update_user = move |ev| { //将闭包传递给按钮组件的onclick参数，更新之前创建signal中的值。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="86"> class="hljs-ln-code"> class="hljs-ln-line"> let v = event_target_value(&ev); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="87"> class="hljs-ln-code"> class="hljs-ln-line"> set_username.set(v); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="88"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="89"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="90"> class="hljs-ln-code"> class="hljs-ln-line"> let update_email = move |ev| { //将闭包传递给按钮组件的onclick参数，更新之前创建signal中的值。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="91"> class="hljs-ln-code"> class="hljs-ln-line"> let v = event_target_value(&ev); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="92"> class="hljs-ln-code"> class="hljs-ln-line"> set_email.set(v); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="93"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="94"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="95"> class="hljs-ln-code"> class="hljs-ln-line"> let insert_db_item = move|ev:SubmitEvent| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="96"> class="hljs-ln-code"> class="hljs-ln-line"> ev.prevent_default(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="97"> class="hljs-ln-code"> class="hljs-ln-line"> spawn_local(async move { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="98"> class="hljs-ln-code"> class="hljs-ln-line"> let username = username.get_untracked(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="99"> class="hljs-ln-code"> class="hljs-ln-line"> let email = email.get_untracked(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="100"> class="hljs-ln-code"> class="hljs-ln-line"> if username.is_empty() { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="101"> class="hljs-ln-code"> class="hljs-ln-line"> return; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="102"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="103"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="104"> class="hljs-ln-code"> class="hljs-ln-line"> let args = serde_wasm_bindgen::to_value(&InsertArgs { username: &username, email:&email }).unwrap(); //参数序列化 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="105"> class="hljs-ln-code"> class="hljs-ln-line"> // Learn more about Tauri commands at https://tauri.app/develop/calling-rust/ class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="106"> class="hljs-ln-code"> class="hljs-ln-line"> let new_msg = invoke("insert_db_item", args).await.as_string().unwrap_or(String::from("Insert Data Failed!!!")); //使用invoke调用insert_db_item命令，greet类似于API class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="107"> class="hljs-ln-code"> class="hljs-ln-line"> set_insert_msg.set(new_msg); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="108"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="109"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="110"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="111"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="112"> class="hljs-ln-code"> class="hljs-ln-line"> let del_last_item = move|ev:SubmitEvent| { class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="113"> class="hljs-ln-code"> class="hljs-ln-line"> ev.prevent_default(); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="114"> class="hljs-ln-code"> class="hljs-ln-line"> spawn_local(async move { //使用Leptos的spawn_local创建一个本地线程(local_thread)Future, 提供一个异步move闭包。 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="115"> class="hljs-ln-code"> class="hljs-ln-line"> let new_msg = invoke_without_args("del_last_user").await.as_string().unwrap_or(String::from("Delete Data Failed!!!")); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="116"> class="hljs-ln-code"> class="hljs-ln-line"> set_insert_msg.set(new_msg); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="117"> class="hljs-ln-code"> class="hljs-ln-line"> }); class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="118"> class="hljs-ln-code"> class="hljs-ln-line"> }; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="119"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="120"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="121"> class="hljs-ln-code"> class="hljs-ln-line"> let clear = move |_| {set_value.set(0);}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="122"> class="hljs-ln-code"> class="hljs-ln-line"> let decrement = move |_| {set_value.update(|v| *v -=1);}; //update()函数接受闭包，参数是signal的setter值set_value class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="123"> class="hljs-ln-code"> class="hljs-ln-line"> let increment = move |_| {set_value.update(|v| *v +=1);}; class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="124"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="125"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="126"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="127"> class="hljs-ln-code"> class="hljs-ln-line"> view! { //view!宏作为App()函数的返回值返回IntoView类型 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="128"> class="hljs-ln-code"> class="hljs-ln-line"> "container"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="129"> class="hljs-ln-code"> class="hljs-ln-line"> "Welcome to Tauri(2.1.1) + Leptos(0.7.2)" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="130"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="131"> class="hljs-ln-code"> class="hljs-ln-line"> "row"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="132"> class="hljs-ln-code"> class="hljs-ln-line"> "https://tauri.app" target="_blank"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="133"> class="hljs-ln-code"> class="hljs-ln-line"> "public/tauri.svg" class="logo tauri" alt="Tauri logo"/> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="134"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="135"> class="hljs-ln-code"> class="hljs-ln-line"> "https://docs.rs/leptos/" target="_blank"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="136"> class="hljs-ln-code"> class="hljs-ln-line"> "public/leptos.svg" class="logo leptos" alt="Leptos logo"/> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="137"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="138"> class="hljs-ln-code"> class="hljs-ln-line"> "https://scybbd.com" target="_blank"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="139"> class="hljs-ln-code"> class="hljs-ln-line"> "public/doughnutS.svg" class="logo scybbd" alt="YislWll's website"/> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="140"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="141"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="142"> class="hljs-ln-code"> class="hljs-ln-line"> "点击Tauri、Leptos和Scybbd的logo了解更多..." class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="143"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="144"> class="hljs-ln-code"> class="hljs-ln-line"> "row" id="greet-form" on:submit=greet> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="145"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="146"> class="hljs-ln-code"> class="hljs-ln-line"> id="greet-input" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="147"> class="hljs-ln-code"> class="hljs-ln-line"> placeholder="请输入一个名字..." class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="148"> class="hljs-ln-code"> class="hljs-ln-line"> on:input=update_name class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="149"> class="hljs-ln-code"> class="hljs-ln-line"> /> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="150"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="151"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="152"> class="hljs-ln-code"> class="hljs-ln-line"> { move || greet_msg.get() } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="153"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="154"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="155"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="156"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="157"> class="hljs-ln-code"> class="hljs-ln-line"> "margin:0 10px 0 10px;" class:red=move||{value.get()<0}>"数值："{value} //当值小于0时，字体变成红色 class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="158"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="159"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="160"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="161"> class="hljs-ln-code"> class="hljs-ln-line"> "row" id="insert-form" on:submit=insert_db_item> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="162"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="163"> class="hljs-ln-code"> class="hljs-ln-line"> id="user-input" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="164"> class="hljs-ln-code"> class="hljs-ln-line"> placeholder="请输入姓名..." class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="165"> class="hljs-ln-code"> class="hljs-ln-line"> on:input=update_user class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="166"> class="hljs-ln-code"> class="hljs-ln-line"> style="margin:0 10px 0 10px;" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="167"> class="hljs-ln-code"> class="hljs-ln-line"> /> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="168"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="169"> class="hljs-ln-code"> class="hljs-ln-line"> id="email-input" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="170"> class="hljs-ln-code"> class="hljs-ln-line"> placeholder="请输入邮箱（可选）..." class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="171"> class="hljs-ln-code"> class="hljs-ln-line"> on:input=update_email class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="172"> class="hljs-ln-code"> class="hljs-ln-line"> style="margin:0 10px 0 10px;" class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="173"> class="hljs-ln-code"> class="hljs-ln-line"> /> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="174"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="175"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="176"> class="hljs-ln-code"> class="hljs-ln-line"> "info">数据库变动信息:{ move || insert_msg.get() } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="177"> class="hljs-ln-code"> class="hljs-ln-line"> "form-container"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="178"> class="hljs-ln-code"> class="hljs-ln-line"> "db-window" id="db-item"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="179"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="180"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="181"> class="hljs-ln-code"> class="hljs-ln-line"> "btn-window"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="182"> class="hljs-ln-code"> class="hljs-ln-line"> "row" on:submit=get_db_item> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="183"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="184"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="185"> class="hljs-ln-code"> class="hljs-ln-line"> "row" on:submit=del_last_item> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="186"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="187"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="188"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="189"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="190"> class="hljs-ln-code"> class="hljs-ln-line"> class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="191"> class="hljs-ln-code"> class="hljs-ln-line"> } class="hljs-ln-numbers"> class="hljs-ln-line hljs-ln-n" data-line-number="192"> class="hljs-ln-code"> class="hljs-ln-line">} class="hide-preCode-box">

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21天学通C++读书笔记（二十三：自适应容器：栈和队列）

1. 栈和队列的行为特征

1.1 栈

1.2 队列

2. 使用STL stack 类

2.1 实例化stack

2.2 stack 的成员函数

2.3 使用 push() 和 pop() 在栈顶插入和删除元素

3. 使用STL queue 类

3.1 实例化queue

3.2 queue 的成员函数

3.3 使用 push() 在队尾插入以及使用 pop() 从队首删除

4. 使用STL 优先级队列

4.1 实例化priority_queue 类

4.2 priority_queue 的成员函数

4.3 使用push()在priority_queue末尾插入以及使用pop()在priority_queue开头删除

Q&A

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