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</script><link rel="stylesheet" href="https://cdn.jsdmirror.com/npm/instantsearch.css/themes/reset-min.css"><link rel="stylesheet" href="https://cdn.jsdmirror.com/npm/@fancyapps/ui@5.0/dist/fancybox/fancybox.css"><link rel="stylesheet" href="https://cdn.jsdmirror.com/npm/@fortawesome/fontawesome-free@6.7.2/css/all.min.css"><title>C# 基本语法 | Bi's Blog</title><link rel="stylesheet" href="/_astro/BaseLayout.D7kFxpxP.css"></head> <body> <header class="site-header"> <nav class="nav"> <a class="brand" href="/">Bi's Blog</a> <button class="nav-menu-toggle" type="button" aria-label="打开菜单" aria-expanded="false" data-nav-toggle> <i class="fa-solid fa-bars nav-menu-open" aria-hidden="true"></i> <i class="fa-solid fa-xmark nav-menu-close" aria-hidden="true"></i> </button> <div class="nav-menu" data-nav-menu> <div class="nav-links nav-center"> <a href="/archives/"><i class="fa-solid fa-box-archive nav-icon" aria-hidden="true"></i><span>归档</span></a><a href="/categories/"><i class="fa-solid fa-folder-open nav-icon" aria-hidden="true"></i><span>分类</span></a><a href="/tags/"><i class="fa-solid fa-tags nav-icon" aria-hidden="true"></i><span>标签</span></a><a href="/shuoshuo/"><i class="fa-regular fa-comments nav-icon" aria-hidden="true"></i><span>说说</span></a><a href="/about/"><i class="fa-solid fa-heart nav-icon" aria-hidden="true"></i><span>关于</span></a><a href="/link/"><i class="fa-solid fa-link nav-icon" aria-hidden="true"></i><span>友链</span></a> </div> <div class="nav-links nav-actions"> <button class="nav-random" type="button" onclick="randomPost()" aria-label="前往随机文章" title="前往随机文章"> <i class="fa-solid fa-shuffle nav-icon" aria-hidden="true"></i> <span>随机文章</span> </button> <button class="nav-search search-typesense-trigger" type="button" aria-label="搜索" title="搜索"> <i class="fa-solid fa-magnifying-glass nav-icon" aria-hidden="true"></i> <span>搜索</span> </button> <button class="theme-toggle" type="button" aria-label="切换夜间模式" title="切换夜间模式" data-theme-toggle> <i class="fa-solid fa-sun theme-toggle-sun nav-icon" aria-hidden="true"></i> <i class="fa-solid fa-moon theme-toggle-moon nav-icon" aria-hidden="true"></i> </button> </div> </div> </nav> </header> <main> <section class="post-layout"> <article class="article post-article"> <header class="article-header"> <div class="article-header-content"> <time datetime="2025-08-16T18:01:10.000Z">2025/08/17</time> <h1>C# 基本语法</h1> <div class="meta-list"> <a href="/categories/study/">学习</a> <a href="/tags/C%23/">#C#</a> </div> </div> </header> <section class="article-summary-card" aria-label="AI 文章摘要"> <div class="article-summary-dots" aria-hidden="true"> <span></span> <span></span> <span></span> </div> <p class="article-summary-content"> <span class="article-summary-text" data-summary-text="这篇文章通过Rectangle示例讲解C#面向对象基础，展示类与对象如何封装数据及行为，并输出面积15.75。随后介绍using引入命名空间、class声明类、注释、成员变量与函数、实例化流程及标识符规则。重点解析C#9顶级语句，无需Main方法即可在文件顶层直接写代码，编译器自动生成入口，适合脚本化开发，示例演示变量、方法、LINQ与异常处理，简化小型项目结构。">这篇文章通过Rectangle示例讲解C#面向对象基础，展示类与对象如何封装数据及行为，并输出面积15.75。随后介绍using引入命名空间、class声明类、注释、成员变量与函数、实例化流程及标识符规则。重点解析C#9顶级语句，无需Main方法即可在文件顶层直接写代码，编译器自动生成入口，适合脚本化开发，示例演示变量、方法、LINQ与异常处理，简化小型项目结构。</span> <span class="article-summary-caret" aria-hidden="true"></span> </p> <div class="article-summary-footer"> <span class="article-summary-brand"> <span aria-hidden="true">✣</span>
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AI摘要
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</span> <span class="article-summary-model">QWEN</span> </div> </section> <div class="prose" data-toc="[{"depth":1,"text":"简介","id":"简介"},{"depth":1,"text":"using 关键字","id":"using-关键字"},{"depth":1,"text":"class 关键字","id":"class-关键字"},{"depth":1,"text":"C# 中的注释","id":"c-中的注释"},{"depth":1,"text":"成员变量","id":"成员变量"},{"depth":1,"text":"标识符","id":"标识符"},{"depth":1,"text":"C# 关键字","id":"c-关键字"},{"depth":1,"text":"顶级语句（Top-Level Statements）","id":"顶级语句top-level-statements"},{"depth":2,"text":"特点：","id":"特点"}]"> <h1 id="简介">简介</h1>
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<p>C# 是一种面向对象的编程语言。在面向对象的程序设计方法中，程序由各种相互交互的对象组成。相同种类的对象通常具有相同的类型，或者说，是在相同的 class 中。</p>
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<p>例如，以 Rectangle（矩形）对象为例。它具有 length 和 width 属性。根据设计，它可能需要接受这些属性值、计算面积和显示细节。</p>
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<p>实例</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#E1E4E8">using System;</span></span>
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<span class="line"><span style="color:#E1E4E8">namespace RectangleApplication</span></span>
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<span class="line"><span style="color:#E1E4E8">{</span></span>
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<span class="line"><span style="color:#E1E4E8"> class Rectangle</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#6A737D"> // 成员变量</span></span>
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<span class="line"><span style="color:#F97583"> double</span><span style="color:#E1E4E8"> length;</span></span>
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<span class="line"><span style="color:#F97583"> double</span><span style="color:#E1E4E8"> width;</span></span>
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<span class="line"><span style="color:#E1E4E8"> public </span><span style="color:#F97583">void</span><span style="color:#B392F0"> Acceptdetails</span><span style="color:#E1E4E8">()</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#E1E4E8"> length </span><span style="color:#F97583">=</span><span style="color:#79B8FF"> 4.5</span><span style="color:#E1E4E8">; </span></span>
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<span class="line"><span style="color:#E1E4E8"> width </span><span style="color:#F97583">=</span><span style="color:#79B8FF"> 3.5</span><span style="color:#E1E4E8">;</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> public </span><span style="color:#F97583">double</span><span style="color:#B392F0"> GetArea</span><span style="color:#E1E4E8">()</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#F97583"> return</span><span style="color:#E1E4E8"> length </span><span style="color:#F97583">*</span><span style="color:#E1E4E8"> width;</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> public </span><span style="color:#F97583">void</span><span style="color:#B392F0"> Display</span><span style="color:#E1E4E8">()</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Length: {0}"</span><span style="color:#E1E4E8">, length);</span></span>
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<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Width: {0}"</span><span style="color:#E1E4E8">, width);</span></span>
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<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Area: {0}"</span><span style="color:#E1E4E8">, </span><span style="color:#B392F0">GetArea</span><span style="color:#E1E4E8">());</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> </span></span>
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<span class="line"><span style="color:#E1E4E8"> class ExecuteRectangle</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#F97583"> static</span><span style="color:#F97583"> void</span><span style="color:#B392F0"> Main</span><span style="color:#E1E4E8">(string</span><span style="color:#F97583">[]</span><span style="color:#E1E4E8"> args)</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#E1E4E8"> Rectangle r </span><span style="color:#F97583">=</span><span style="color:#E1E4E8"> new </span><span style="color:#B392F0">Rectangle</span><span style="color:#E1E4E8">();</span></span>
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<span class="line"><span style="color:#E1E4E8"> r.</span><span style="color:#B392F0">Acceptdetails</span><span style="color:#E1E4E8">();</span></span>
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<span class="line"><span style="color:#E1E4E8"> r.</span><span style="color:#B392F0">Display</span><span style="color:#E1E4E8">();</span></span>
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<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">ReadLine</span><span style="color:#E1E4E8">();</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8">}</span></span></code></pre>
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<p>尝试一下 »
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当上面的代码被编译和执行时，它会产生下列结果：</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="plaintext"><code><span class="line"><span>Length: 4.5</span></span>
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<span class="line"><span>Width: 3.5</span></span>
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<span class="line"><span>Area: 15.75</span></span></code></pre>
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<h1 id="using-关键字">using 关键字</h1>
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<p>在任何 C# 程序中的第一条语句都是：</p>
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<p>using System;
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using 关键字用于在程序中包含命名空间。一个程序可以包含多个 using 语句。</p>
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<h1 id="class-关键字">class 关键字</h1>
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<p>class 关键字用于声明一个类。</p>
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<h1 id="c-中的注释">C# 中的注释</h1>
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<p>注释是用于解释代码。编译器会忽略注释的条目。在 C# 程序中，多行注释以 /* 开始，并以字符 */ 终止，如下所示：</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#6A737D">/* 这个程序演示</span></span>
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<span class="line"><span style="color:#6A737D">C# 的注释</span></span>
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<span class="line"><span style="color:#6A737D">使用 */</span></span></code></pre>
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<p>单行注释是用 // 符号表示。例如：</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#6A737D">// 这一行是注释 </span></span></code></pre>
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<h1 id="成员变量">成员变量</h1>
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<p>变量是类的属性或数据成员，用于存储数据。在上面的程序中，Rectangle 类有两个成员变量，名为 length 和 width。</p>
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<p>成员函数
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函数是一系列执行指定任务的语句。类的成员函数是在类内声明的。我们举例的类 Rectangle 包含了三个成员函数： AcceptDetails、GetArea 和 Display。</p>
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<p>实例化一个类
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在上面的程序中，类 ExecuteRectangle 是一个包含 Main() 方法和实例化 Rectangle 类的类。</p>
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<h1 id="标识符">标识符</h1>
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<p>标识符是用来识别类、变量、函数或任何其它用户定义的项目。在 C# 中，类的命名必须遵循如下基本规则：</p>
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<ul>
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<li>标识符必须以字母、下划线或 @ 开头，后面可以跟一系列的字母、数字（ 0 - 9 ）、下划线（ _ ）、@。</li>
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<li>标识符中的第一个字符不能是数字。</li>
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<li>标识符必须不包含任何嵌入的空格或符号，比如 ? - +! # % ^ & * ( ) [ ] { } . ; : ” ’ / \。</li>
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<li>标识符不能是 C# 关键字。除非它们有一个 @ 前缀。 例如，@if 是有效的标识符，但 if 不是，因为 if 是关键字。</li>
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<li>标识符必须区分大小写。大写字母和小写字母被认为是不同的字母。</li>
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<li>不能与C#的类库名称相同。</li>
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</ul>
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<h1 id="c-关键字">C# 关键字</h1>
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<p>关键字是 C# 编译器预定义的保留字。这些关键字不能用作标识符，但是，如果您想使用这些关键字作为标识符，可以在关键字前面加上 @ 字符作为前缀。</p>
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<p>在 C# 中，有些关键字在代码的上下文中有特殊的意义，如 get 和 set，这些被称为上下文关键字（contextual keywords）。</p>
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<h1 id="顶级语句top-level-statements">顶级语句（Top-Level Statements）</h1>
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<p>在 C# 9.0 版本中，引入了顶级语句（Top-Level Statements）的概念，这是一种新的编程范式，允许开发者在文件的顶层直接编写语句，而不需要将它们封装在方法或类中。</p>
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<h2 id="特点">特点：</h2>
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<p>无需类或方法：顶级语句允许你直接在文件的顶层编写代码，无需定义类或方法。</p>
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<p>文件作为入口点：包含顶级语句的文件被视为程序的入口点，类似于 C# 之前的 Main 方法。</p>
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<p>自动 Main 方法：编译器会自动生成一个 Main 方法，并将顶级语句作为 Main 方法的主体。</p>
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<p>支持局部函数：尽管不需要定义类，但顶级语句的文件中仍然可以定义局部函数。</p>
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<p>更好的可读性：对于简单的脚本或工具，顶级语句提供了更好的可读性和简洁性。</p>
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<p>适用于小型项目：顶级语句非常适合小型项目或脚本，可以快速编写和运行代码。</p>
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<p>与现有代码兼容：顶级语句可以与现有的 C# 代码库一起使用，不会影响现有代码。</p>
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<p>传统 C# 代码 - 在使用顶级语句之前，你必须像这样编写一个 C# 程序：</p>
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<p>实例</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#E1E4E8">using System;</span></span>
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<span class="line"></span>
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<span class="line"><span style="color:#E1E4E8">namespace MyApp</span></span>
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<span class="line"><span style="color:#E1E4E8">{</span></span>
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<span class="line"><span style="color:#E1E4E8"> class Program</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#F97583"> static</span><span style="color:#F97583"> void</span><span style="color:#B392F0"> Main</span><span style="color:#E1E4E8">(string</span><span style="color:#F97583">[]</span><span style="color:#E1E4E8"> args)</span></span>
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<span class="line"><span style="color:#E1E4E8"> {</span></span>
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<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Hello, World!"</span><span style="color:#E1E4E8">);</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8"> }</span></span>
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<span class="line"><span style="color:#E1E4E8">}</span></span></code></pre>
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<p>使用顶级语句的 C# 代码 - 使用顶级语句，可以简化为：</p>
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<p>实例</p>
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<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#E1E4E8">using System;</span></span>
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<span class="line"></span>
|
||
<span class="line"><span style="color:#E1E4E8">Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Hello, World!"</span><span style="color:#E1E4E8">);</span></span></code></pre>
|
||
<p>顶级语句支持所有常见的 C# 语法，包括声明变量、定义方法、处理异常等。</p>
|
||
<p>实例</p>
|
||
<pre class="astro-code github-dark" style="background-color:#24292e;color:#e1e4e8; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;" tabindex="0" data-language="c"><code><span class="line"><span style="color:#E1E4E8">using System;</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">using System.Linq;</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="color:#6A737D">// 顶级语句中的变量声明</span></span>
|
||
<span class="line"><span style="color:#F97583">int</span><span style="color:#E1E4E8"> number </span><span style="color:#F97583">=</span><span style="color:#79B8FF"> 42</span><span style="color:#E1E4E8">;</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">string message </span><span style="color:#F97583">=</span><span style="color:#9ECBFF"> "The answer to life, the universe, and everything is"</span><span style="color:#E1E4E8">;</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="color:#6A737D">// 输出变量</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">($</span><span style="color:#9ECBFF">"{message} {number}."</span><span style="color:#E1E4E8">);</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="color:#6A737D">// 定义和调用方法</span></span>
|
||
<span class="line"><span style="color:#F97583">int</span><span style="color:#B392F0"> Add</span><span style="color:#E1E4E8">(</span><span style="color:#F97583">int</span><span style="color:#FFAB70"> a</span><span style="color:#E1E4E8">, </span><span style="color:#F97583">int</span><span style="color:#FFAB70"> b</span><span style="color:#E1E4E8">) </span><span style="color:#F97583">=></span><span style="color:#E1E4E8"> a </span><span style="color:#F97583">+</span><span style="color:#E1E4E8"> b;</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">($</span><span style="color:#9ECBFF">"Sum of 1 and 2 is {Add(1, 2)}."</span><span style="color:#E1E4E8">);</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="color:#6A737D">// 使用 LINQ</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">var numbers </span><span style="color:#F97583">=</span><span style="color:#E1E4E8"> new</span><span style="color:#F97583">[]</span><span style="color:#E1E4E8"> { </span><span style="color:#79B8FF">1</span><span style="color:#E1E4E8">, </span><span style="color:#79B8FF">2</span><span style="color:#E1E4E8">, </span><span style="color:#79B8FF">3</span><span style="color:#E1E4E8">, </span><span style="color:#79B8FF">4</span><span style="color:#E1E4E8">, </span><span style="color:#79B8FF">5</span><span style="color:#E1E4E8"> };</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">var evens </span><span style="color:#F97583">=</span><span style="color:#E1E4E8"> numbers.</span><span style="color:#B392F0">Where</span><span style="color:#E1E4E8">(n </span><span style="color:#F97583">=></span><span style="color:#E1E4E8"> n </span><span style="color:#F97583">%</span><span style="color:#79B8FF"> 2</span><span style="color:#F97583"> ==</span><span style="color:#79B8FF"> 0</span><span style="color:#E1E4E8">).</span><span style="color:#B392F0">ToArray</span><span style="color:#E1E4E8">();</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Even numbers: "</span><span style="color:#F97583"> +</span><span style="color:#E1E4E8"> string.</span><span style="color:#B392F0">Join</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">", "</span><span style="color:#E1E4E8">, evens));</span></span>
|
||
<span class="line"></span>
|
||
<span class="line"><span style="color:#6A737D">// 异常处理</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">try</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">{</span></span>
|
||
<span class="line"><span style="color:#F97583"> int</span><span style="color:#E1E4E8"> zero </span><span style="color:#F97583">=</span><span style="color:#79B8FF"> 0</span><span style="color:#E1E4E8">;</span></span>
|
||
<span class="line"><span style="color:#F97583"> int</span><span style="color:#E1E4E8"> result </span><span style="color:#F97583">=</span><span style="color:#E1E4E8"> number </span><span style="color:#F97583">/</span><span style="color:#E1E4E8"> zero;</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">}</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">catch (DivideByZeroException ex)</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">{</span></span>
|
||
<span class="line"><span style="color:#E1E4E8"> Console.</span><span style="color:#B392F0">WriteLine</span><span style="color:#E1E4E8">(</span><span style="color:#9ECBFF">"Error: "</span><span style="color:#F97583"> +</span><span style="color:#E1E4E8"> ex.Message);</span></span>
|
||
<span class="line"><span style="color:#E1E4E8">}</span></span></code></pre> </div> <section class="post-copyright-card" aria-label="文章版权信息"> <div class="post-copyright-mark" aria-hidden="true"> <span>CC</span> </div> <div class="post-copyright-main"> <h2>C# 基本语法</h2> <a class="post-copyright-link" href="/posts/e9a8e898/">/posts/e9a8e898/</a> <dl class="post-copyright-meta"> <div> <dt>作者</dt> <dd>biss</dd> </div> <div> <dt>发布于</dt> <dd><time datetime="2025-08-16T18:01:10.000Z">2025/08/17</time></dd> </div> <div> <dt>许可协议</dt> <dd><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" target="_blank" rel="noreferrer">CC BY-NC-SA 4.0</a></dd> </div> </dl> </div> <div class="post-copyright-footer"> <div class="post-copyright-tags" aria-label="文章标签"> <a href="/tags/C%23/">C#</a> </div> <div class="post-copyright-actions" aria-label="文章操作"> <button class="post-copyright-action is-primary post-share-button" type="button" data-share-title="C# 基本语法" data-share-url="https://blog.biss.click/posts/e9a8e898/" title="分享文章"> <svg aria-hidden="true" viewBox="0 0 24 24"> <path d="M4 12v7a1 1 0 0 0 1 1h14a1 1 0 0 0 1-1v-7"></path> <path d="M12 16V4"></path> <path d="m7 9 5-5 5 5"></path> </svg> <span>分享</span> </button> <a class="post-copyright-action" href="/rss.xml" title="订阅 RSS"> <svg aria-hidden="true" viewBox="0 0 24 24"> <path d="M5 5a14 14 0 0 1 14 14"></path> <path d="M5 11a8 8 0 0 1 8 8"></path> <path d="M6 18h.01"></path> </svg> <span>订阅</span> </a> <a class="post-copyright-action" href="/about/" title="打赏作者"> <svg aria-hidden="true" viewBox="0 0 24 24"> <path d="M7 8h10"></path> <path d="M8 8V5h8v3"></path> <path d="M6 8h12l-1.5 11h-9L6 8Z"></path> <path d="M10 12h4"></path> </svg> <span>打赏</span> </a> <a class="post-copyright-icon" href="https://twitter.com/intent/tweet?url=https%3A%2F%2Fblog.biss.click%2Fposts%2Fe9a8e898%2F&text=C%23%20%E5%9F%BA%E6%9C%AC%E8%AF%AD%E6%B3%95" target="_blank" rel="noreferrer" title="分享到 X"> <span aria-hidden="true">x</span> </a> <a class="post-copyright-icon" href="https://service.weibo.com/share/share.php?url=https%3A%2F%2Fblog.biss.click%2Fposts%2Fe9a8e898%2F&title=C%23%20%E5%9F%BA%E6%9C%AC%E8%AF%AD%E6%B3%95" target="_blank" rel="noreferrer" title="分享到微博"> <span aria-hidden="true">微</span> </a> </div> </div> </section> <script>
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</script> </article> <aside class="article-sidebar" aria-label="文章侧边栏"> <section class="sidebar-card article-author-card"> <img class="profile-avatar" src="https://free.picui.cn/free/2025/08/10/689845496a283.png" alt="biss" loading="lazy"> <div class="profile-name">biss</div> <div class="article-author-meta"> <span>2025/08/17</span> <a href="/categories/study/">学习</a> </div> </section> <section class="sidebar-card article-tags-card"> <h2> <span aria-hidden="true">#</span>
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||
文章标签
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||
<em>1</em> </h2> <div class="article-tag-list" aria-label="文章标签"> <a href="/tags/C%23/">#C#</a> </div> </section> <div class="article-sticky-sidebar"> <section class="sidebar-card toc-card"> <h2> <span aria-hidden="true">☰</span>
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||
文章目录
|
||
<em>9</em> </h2> <nav class="toc-list toc-tree" aria-label="文章目录" data-toc-tree> <div class="toc-group is-open" data-toc-group data-heading-id="简介"> <a class="toc-link toc-link-main" href="#简介" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>简介</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="using-关键字"> <a class="toc-link toc-link-main" href="#using-关键字" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>using 关键字</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="class-关键字"> <a class="toc-link toc-link-main" href="#class-关键字" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>class 关键字</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="c-中的注释"> <a class="toc-link toc-link-main" href="#c-中的注释" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>C# 中的注释</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="成员变量"> <a class="toc-link toc-link-main" href="#成员变量" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>成员变量</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="标识符"> <a class="toc-link toc-link-main" href="#标识符" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>标识符</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="c-关键字"> <a class="toc-link toc-link-main" href="#c-关键字" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>C# 关键字</span> </a> </div><div class="toc-group" data-toc-group data-heading-id="顶级语句top-level-statements"> <a class="toc-link toc-link-main" href="#顶级语句top-level-statements" data-toc-link data-toc-top> <span class="toc-marker" aria-hidden="true"></span> <span>顶级语句（Top-Level Statements）</span> </a> <div class="toc-children" data-toc-children> <a class="toc-link toc-link-child toc-depth-2" href="#特点" data-toc-link> <span>特点：</span> </a> </div> </div> </nav> </section> <section class="sidebar-card same-category-card"> <h2> <span aria-hidden="true">▣</span>
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code.dataset.language ||
|
||
[...pre.classList, ...code.classList]
|
||
.find((className) => className.startsWith('language-'))
|
||
?.replace(/^language-/, '') ||
|
||
'';
|
||
|
||
const normalized = rawLanguage.trim().toLowerCase();
|
||
return languageNames[normalized] || normalized.toUpperCase() || 'Code';
|
||
}
|
||
|
||
function getCodeText(code, lines) {
|
||
if (lines.length > 0) return lines.map((line) => line.textContent || '').join('\n');
|
||
return code.textContent || '';
|
||
}
|
||
|
||
prose.querySelectorAll('img').forEach((image) => {
|
||
if (image.closest('a, .article-header-cover')) return;
|
||
|
||
const src = image.currentSrc || image.getAttribute('src');
|
||
if (!src) return;
|
||
|
||
const link = document.createElement('a');
|
||
link.className = 'fancybox';
|
||
link.href = src;
|
||
link.dataset.fancybox = 'article-gallery';
|
||
link.dataset.caption = image.getAttribute('alt') || '';
|
||
image.parentNode?.insertBefore(link, image);
|
||
link.appendChild(image);
|
||
});
|
||
|
||
prose.querySelectorAll('table').forEach((table) => {
|
||
if (table.closest('.table-scroll')) return;
|
||
|
||
const wrapper = document.createElement('div');
|
||
wrapper.className = 'table-scroll';
|
||
table.parentNode?.insertBefore(wrapper, table);
|
||
wrapper.appendChild(table);
|
||
});
|
||
|
||
prose.querySelectorAll('.butterfly-hide-inline').forEach((item) => {
|
||
const button = item.querySelector('.butterfly-hide-toggle');
|
||
if (!button) return;
|
||
|
||
button.addEventListener('click', () => {
|
||
item.classList.toggle('is-open');
|
||
});
|
||
});
|
||
|
||
if (window.Fancybox) {
|
||
window.Fancybox.bind('[data-fancybox="article-gallery"]', {
|
||
compact: false,
|
||
dragToClose: true,
|
||
Images: {
|
||
zoom: true,
|
||
},
|
||
});
|
||
}
|
||
|
||
async function copyText(text) {
|
||
if (navigator.clipboard?.writeText) {
|
||
await navigator.clipboard.writeText(text);
|
||
return;
|
||
}
|
||
|
||
const textarea = document.createElement('textarea');
|
||
textarea.value = text;
|
||
textarea.setAttribute('readonly', '');
|
||
textarea.style.position = 'fixed';
|
||
textarea.style.top = '-9999px';
|
||
textarea.style.opacity = '0';
|
||
document.body.appendChild(textarea);
|
||
textarea.select();
|
||
document.execCommand('copy');
|
||
textarea.remove();
|
||
}
|
||
|
||
prose.querySelectorAll('pre').forEach((pre) => {
|
||
if (pre.closest('.code-block')) return;
|
||
|
||
const code = pre.querySelector('code');
|
||
if (!code) return;
|
||
|
||
const wrapper = document.createElement('div');
|
||
wrapper.className = 'code-block';
|
||
pre.parentNode?.insertBefore(wrapper, pre);
|
||
wrapper.appendChild(pre);
|
||
|
||
const header = document.createElement('div');
|
||
header.className = 'code-block-header';
|
||
|
||
const language = document.createElement('span');
|
||
language.className = 'code-block-language';
|
||
language.textContent = getCodeLanguage(pre, code);
|
||
|
||
const toolbar = document.createElement('div');
|
||
toolbar.className = 'code-block-toolbar';
|
||
|
||
const copyButton = document.createElement('button');
|
||
copyButton.className = 'code-block-copy';
|
||
copyButton.type = 'button';
|
||
copyButton.textContent = copyLabels.idle;
|
||
copyButton.setAttribute('aria-label', '复制代码');
|
||
|
||
const toggleButton = document.createElement('button');
|
||
toggleButton.className = 'code-block-toggle';
|
||
toggleButton.type = 'button';
|
||
toggleButton.textContent = '展开';
|
||
toggleButton.setAttribute('aria-expanded', 'false');
|
||
|
||
toolbar.append(copyButton, toggleButton);
|
||
header.append(language, toolbar);
|
||
wrapper.appendChild(header);
|
||
|
||
const codeLines = [...code.querySelectorAll(':scope > .line')];
|
||
if (codeLines.length > 0) {
|
||
wrapper.classList.add('has-line-numbers');
|
||
wrapper.style.setProperty('--line-number-width', `${String(codeLines.length).length + 1}ch`);
|
||
codeLines.forEach((line, index) => {
|
||
line.dataset.line = String(index + 1);
|
||
});
|
||
}
|
||
|
||
const lineCount = codeLines.length || (code.textContent || '').split(/\r?\n/).length;
|
||
if (lineCount > collapsedLineCount) wrapper.classList.add('is-collapsible');
|
||
|
||
copyButton.addEventListener('click', async () => {
|
||
try {
|
||
await copyText(getCodeText(code, codeLines));
|
||
copyButton.textContent = copyLabels.done;
|
||
window.setTimeout(() => {
|
||
copyButton.textContent = copyLabels.idle;
|
||
}, 1400);
|
||
} catch {
|
||
copyButton.textContent = copyLabels.error;
|
||
window.setTimeout(() => {
|
||
copyButton.textContent = copyLabels.idle;
|
||
}, 1600);
|
||
}
|
||
});
|
||
|
||
toggleButton.addEventListener('click', () => {
|
||
const isExpanded = wrapper.classList.toggle('is-expanded');
|
||
toggleButton.textContent = isExpanded ? '收起' : '展开';
|
||
toggleButton.setAttribute('aria-expanded', String(isExpanded));
|
||
});
|
||
});
|
||
})();
|
||
</script> |