{"id":3535,"date":"2025-04-13T14:01:07","date_gmt":"2025-04-13T06:01:07","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3535"},"modified":"2025-04-13T14:01:07","modified_gmt":"2025-04-13T06:01:07","slug":"c-%e9%a2%84%e5%a4%84%e7%90%86%e5%99%a8%e6%8c%87%e4%bb%a4%ef%bc%88preprocessor-directives%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/04\/13\/c-%e9%a2%84%e5%a4%84%e7%90%86%e5%99%a8%e6%8c%87%e4%bb%a4%ef%bc%88preprocessor-directives%ef%bc%89\/","title":{"rendered":"C# \u9884\u5904\u7406\u5668\u6307\u4ee4\uff08Preprocessor Directives\uff09"},"content":{"rendered":"\n<p>\u672c\u7ae0\u8282\u662f\u5173\u4e8e <strong>C# \u9884\u5904\u7406\u5668\u6307\u4ee4\uff08Preprocessor Directives\uff09<\/strong> \u7684\u5168\u9762\u3001\u8be6\u7ec6\u3001\u4e13\u4e1a\u8bb2\u89e3\uff0c\u7ed3\u5408\u6743\u5a01\u8d44\u6599\uff0c\u6db5\u76d6\u5e38\u89c1\u6307\u4ee4\u3001\u8bed\u6cd5\u89c4\u5219\u3001\u4f7f\u7528\u573a\u666f\u3001\u6700\u4f73\u5b9e\u8df5\u548c\u793a\u4f8b\u4ee3\u7801\uff0c\u9002\u5408\u521d\u5b66\u5f00\u53d1\u8005\u5b66\u4e60\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">1. \u4ec0\u4e48\u662f\u9884\u5904\u7406\u5668\u6307\u4ee4\uff1f<\/h2>\n\n\n\n<p>C# \u9884\u5904\u7406\u5668\u6307\u4ee4\u662f\u4ee5 <code>#<\/code> \u5f00\u5934\u7684\u4e00\u7cfb\u5217\u6307\u4ee4\uff0c<strong>\u5728\u4ee3\u7801\u7f16\u8bd1\u524d\u7531\u7f16\u8bd1\u5668\u5904\u7406<\/strong>\uff0c\u4f46\u4e0d\u662f\u7531 CLR\uff08\u516c\u5171\u8bed\u8a00\u8fd0\u884c\u65f6\uff09\u6267\u884c\u7684\u3002\u8fd9\u4e9b\u6307\u4ee4\u4e0d\u662f\u771f\u6b63\u610f\u4e49\u4e0a\u7684 C# \u8bed\u53e5\uff0c<strong>\u4e0d\u80fd\u5f71\u54cd\u8fd0\u884c\u65f6\u884c\u4e3a\uff0c\u4f46\u53ef\u63a7\u5236\u7f16\u8bd1\u884c\u4e3a<\/strong>\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\ud83c\udfaf \u901a\u5e38\u7528\u4e8e\u6761\u4ef6\u7f16\u8bd1\u3001\u8c03\u8bd5\u3001\u4ee3\u7801\u7ec4\u7ec7\u7b49\u76ee\u7684\u3002<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">2. \u5e38\u89c1\u9884\u5904\u7406\u5668\u6307\u4ee4\u53ca\u8bf4\u660e<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6307\u4ee4<\/th><th>\u8bf4\u660e<\/th><\/tr><\/thead><tbody><tr><td><code>#define<\/code><\/td><td>\u5b9a\u4e49\u7b26\u53f7<\/td><\/tr><tr><td><code>#undef<\/code><\/td><td>\u53d6\u6d88\u5b9a\u4e49\u7b26\u53f7<\/td><\/tr><tr><td><code>#if<\/code> \/ <code>#elif<\/code> \/ <code>#else<\/code> \/ <code>#endif<\/code><\/td><td>\u6761\u4ef6\u7f16\u8bd1<\/td><\/tr><tr><td><code>#warning<\/code><\/td><td>\u7f16\u8bd1\u65f6\u663e\u793a\u8b66\u544a\u4fe1\u606f<\/td><\/tr><tr><td><code>#error<\/code><\/td><td>\u7f16\u8bd1\u65f6\u4e2d\u6b62\u5e76\u663e\u793a\u9519\u8bef\u4fe1\u606f<\/td><\/tr><tr><td><code>#region<\/code> \/ <code>#endregion<\/code><\/td><td>\u6298\u53e0\u4ee3\u7801\u533a\u57df\uff08\u4ec5\u5bf9 IDE \u6709\u6548\uff09<\/td><\/tr><tr><td><code>#pragma<\/code><\/td><td>\u63a7\u5236\u7f16\u8bd1\u5668\u884c\u4e3a\uff08\u5982\u7981\u7528\u8b66\u544a\uff09<\/td><\/tr><tr><td><code>#line<\/code><\/td><td>\u63a7\u5236\u884c\u53f7\u4e0e\u6587\u4ef6\u540d\uff08\u7528\u4e8e\u8c03\u8bd5\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3. \u57fa\u672c\u4f7f\u7528\u793a\u4f8b<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">3.1 \u5b9a\u4e49\u548c\u4f7f\u7528\u7b26\u53f7<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>#define DEBUG\nusing System;\n\nclass Program {\n    static void Main() {\n#if DEBUG\n        Console.WriteLine(\"\u8c03\u8bd5\u6a21\u5f0f\");\n#else\n        Console.WriteLine(\"\u53d1\u5e03\u6a21\u5f0f\");\n#endif\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3.2 <code>#undef<\/code> \u793a\u4f8b<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>#define TEST\n#undef TEST\n\n#if TEST\nConsole.WriteLine(\"\u6d4b\u8bd5\u4ee3\u7801\");\n#endif<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3.3 <code>#warning<\/code> \u4e0e <code>#error<\/code><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>#warning \u8fd9\u662f\u4e00\u4e2a\u8b66\u544a\u63d0\u793a\uff0c\u4ec5\u7528\u4e8e\u5f00\u53d1\u73af\u5883\n#error \u7f16\u8bd1\u5df2\u4e2d\u6b62\uff0c\u539f\u56e0\uff1a\u914d\u7f6e\u9519\u8bef<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3.4 <code>#region<\/code> \u548c <code>#endregion<\/code><\/h3>\n\n\n\n<p>\u7528\u4e8e\u4ee3\u7801\u6298\u53e0\uff0c\u5728 Visual Studio\u3001Rider\u3001VS Code \u7b49 IDE \u4e2d\u5e38\u89c1\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#region \u6570\u636e\u8bbf\u95ee\u5c42\npublic class Repository {\n    \/\/ \u5b9e\u73b0\u4ee3\u7801\n}\n#endregion<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3.5 <code>#pragma warning<\/code> \u793a\u4f8b<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>#pragma warning disable CS0168  \/\/ \u7981\u7528\u201c\u53d8\u91cf\u58f0\u660e\u4f46\u672a\u4f7f\u7528\u201d\u8b66\u544a\nint unusedVar;\n#pragma warning restore CS0168<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">4. \u591a\u6761\u4ef6\u7f16\u8bd1<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>#define DEBUG\n#define VERBOSE\n\n#if DEBUG &amp;&amp; VERBOSE\nConsole.WriteLine(\"\u8c03\u8bd5 + \u8be6\u7ec6\u4fe1\u606f\");\n#elif DEBUG\nConsole.WriteLine(\"\u8c03\u8bd5\u6a21\u5f0f\");\n#else\nConsole.WriteLine(\"\u666e\u901a\u6a21\u5f0f\");\n#endif<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">5. \u4e0e\u7f16\u8bd1\u5668\u53c2\u6570\u914d\u5408\u4f7f\u7528\uff08MSBuild\uff09<\/h2>\n\n\n\n<p>\u5728\u9879\u76ee\u5c5e\u6027\u6216 <code>.csproj<\/code> \u4e2d\u8bbe\u7f6e\u6761\u4ef6\u7b26\u53f7\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;PropertyGroup&gt;\n  &lt;DefineConstants&gt;DEBUG;TRACE;MYCUSTOM&lt;\/DefineConstants&gt;\n&lt;\/PropertyGroup&gt;<\/code><\/pre>\n\n\n\n<p>\ud83d\udd27 \u4f60\u4e5f\u53ef\u4ee5\u5728\u547d\u4ee4\u884c\u4e2d\u4f7f\u7528 <code>\/define<\/code>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>csc \/define:DEBUG Program.cs<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">6. \u6ce8\u610f\u4e8b\u9879<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e0d\u652f\u6301\u5b8f\u5b9a\u4e49\uff08\u5982 C\/C++ \u7684 <code>#define MAX(a,b)<\/code>\uff09<\/li>\n\n\n\n<li>\u6307\u4ee4\u4f5c\u7528\u8303\u56f4\u662f\u6574\u4e2a\u6587\u4ef6\uff0c\u4e0d\u80fd\u5728\u51fd\u6570\u5185\u90e8\u5b9a\u4e49<\/li>\n\n\n\n<li>\u4e0d\u5efa\u8bae\u6ee5\u7528\u6761\u4ef6\u7f16\u8bd1\uff0c\u5f71\u54cd\u4ee3\u7801\u53ef\u8bfb\u6027<\/li>\n\n\n\n<li>\u63a8\u8350\u7528 <code>#region<\/code> \u5408\u7406\u7ec4\u7ec7\u5927\u578b\u7c7b\u7ed3\u6784\uff0c\u63d0\u5347\u5f00\u53d1\u4f53\u9a8c<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">7. \u4f7f\u7528\u573a\u666f\u603b\u7ed3<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u573a\u666f<\/th><th>\u63a8\u8350\u6307\u4ee4<\/th><\/tr><\/thead><tbody><tr><td>\u591a\u73af\u5883\u8c03\u8bd5\uff08\u8c03\u8bd5 vs \u53d1\u5e03\uff09<\/td><td><code>#if DEBUG<\/code><\/td><\/tr><tr><td>\u5927\u578b\u9879\u76ee\u4ee3\u7801\u7ba1\u7406<\/td><td><code>#region<\/code><\/td><\/tr><tr><td>\u53ef\u9009\u6a21\u5757\u529f\u80fd\u63a7\u5236<\/td><td><code>#if FEATURE_X<\/code><\/td><\/tr><tr><td>\u9759\u6001\u4ee3\u7801\u5206\u6790\u5904\u7406<\/td><td><code>#pragma warning<\/code><\/td><\/tr><tr><td>\u7981\u7528\u672a\u4f7f\u7528\u53d8\u91cf\u7b49\u8b66\u544a<\/td><td><code>#pragma warning disable<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">8. \u5b98\u65b9\u6587\u6863\u4e0e\u6743\u5a01\u53c2\u8003<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\ud83d\udd17 <a href=\"https:\/\/learn.microsoft.com\/en-us\/dotnet\/csharp\/language-reference\/preprocessor-directives\/\">Microsoft Learn: Preprocessor Directives<\/a><\/li>\n\n\n\n<li>\ud83d\udd17 <a href=\"https:\/\/learn.microsoft.com\/en-us\/dotnet\/csharp\/language-reference\/preprocessor-directives\/preprocessor-if\">#if Directive &#8211; C# Reference<\/a><\/li>\n\n\n\n<li>\ud83d\udd17 <a href=\"https:\/\/learn.microsoft.com\/en-us\/dotnet\/csharp\/misc\/\">C# \u7f16\u8bd1\u5668\u8b66\u544a\u4ee3\u7801\u5217\u8868\uff08CS\u5f00\u5934\uff09<\/a><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">9. \u5b9e\u6218\u6280\u5de7\u4e0e\u6700\u4f73\u5b9e\u8df5<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u2705 \u4f7f\u7528 <code>#region<\/code> \u5206\u533a\u5927\u578b\u7c7b\uff0c\u5982\u6a21\u578b\u3001\u5c5e\u6027\u3001\u65b9\u6cd5\u3001\u79c1\u6709\u65b9\u6cd5\u7b49<\/li>\n\n\n\n<li>\u2705 \u5728\u591a\u5e73\u53f0\u9879\u76ee\u4e2d\u4f7f\u7528\u7b26\u53f7\u533a\u5206\uff08\u5982 Windows \/ Linux\uff09<\/li>\n\n\n\n<li>\u2705 \u4f7f\u7528 <code>#pragma warning disable<\/code> \u5904\u7406\u4ec5\u5728\u7279\u5b9a\u5e73\u53f0\u4e0b\u89e6\u53d1\u7684\u8b66\u544a<\/li>\n\n\n\n<li>\u26a0\ufe0f \u5c3d\u91cf\u907f\u514d\u590d\u6742\u7684\u6761\u4ef6\u5d4c\u5957\uff0c\u63a8\u8350\u7528\u914d\u7f6e\u7ba1\u7406\uff08\u5982 appsettings\uff09\u66ff\u4ee3\u8fd0\u884c\u671f\u903b\u8f91\u63a7\u5236<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u7ae0\u8282\u662f\u5173\u4e8e C# \u9884\u5904\u7406\u5668\u6307\u4ee4\uff08Preprocessor Directives\uff09 \u7684\u5168\u9762\u3001\u8be6\u7ec6\u3001\u4e13\u4e1a\u8bb2\u89e3\uff0c\u7ed3 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3536,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[83],"tags":[],"class_list":["post-3535","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-c-"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3535","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=3535"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3535\/revisions"}],"predecessor-version":[{"id":3537,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3535\/revisions\/3537"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3536"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3535"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3535"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}