{"id":57798,"date":"2024-10-10T21:13:36","date_gmt":"2024-10-10T13:13:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/57798\/"},"modified":"2024-10-10T21:13:36","modified_gmt":"2024-10-10T13:13:36","slug":"go%e6%95%99%e7%a8%8b-go-%e8%aa%9e%e8%a8%80-defer%ef%bc%88%e5%bb%b6%e9%81%b2%e5%9f%b7%e8%a1%8c%e8%aa%9e%e5%8f%a5%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/57798\/","title":{"rendered":"GO\u6559\u7a0b: Go \u8a9e\u8a00 defer\uff08\u5ef6\u9072\u57f7\u884c\u8a9e\u53e5\uff09"},"content":{"rendered":"<h1 id=\"go%e6%95%99%e7%a8%8b-go-%e8%aa%9e%e8%a8%80-defer%ef%bc%88%e5%bb%b6%e9%81%b2%e5%9f%b7%e8%a1%8c%e8%aa%9e%e5%8f%a5%ef%bc%89-JQSBnaFAjx\">GO\u6559\u7a0b: Go \u8a9e\u8a00 defer\uff08\u5ef6\u9072\u57f7\u884c\u8a9e\u53e5\uff09<\/h1>\n<p>\u5728 Go \u8a9e\u8a00\u4e2d\uff0c<code>defer<\/code> \u662f\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u95dc\u9375\u5b57\uff0c\u5141\u8a31\u958b\u767c\u8005\u5728\u51fd\u6578\u57f7\u884c\u7d50\u675f\u6642\u5ef6\u9072\u57f7\u884c\u67d0\u4e9b\u8a9e\u53e5\u3002\u9019\u5c0d\u65bc\u8cc7\u6e90\u7ba1\u7406\u3001\u932f\u8aa4\u8655\u7406\u4ee5\u53ca\u78ba\u4fdd\u6e05\u7406\u5de5\u4f5c\u80fd\u5920\u5728\u51fd\u6578\u7d50\u675f\u6642\u81ea\u52d5\u57f7\u884c\u975e\u5e38\u91cd\u8981\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e <code>defer<\/code> \u7684\u7528\u6cd5\u53ca\u5176\u5728\u5be6\u969b\u958b\u767c\u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"1-defer-%e7%9a%84%e5%9f%ba%e6%9c%ac%e7%94%a8%e6%b3%95-JQSBnaFAjx\">1. defer \u7684\u57fa\u672c\u7528\u6cd5<\/h2>\n<p>\u7576\u4f60\u5728\u51fd\u6578\u4e2d\u4f7f\u7528 <code>defer<\/code> \u95dc\u9375\u5b57\u6642\uff0c\u5f8c\u9762\u7684\u8a9e\u53e5\u6703\u5728\u51fd\u6578\u8fd4\u56de\u4e4b\u524d\u57f7\u884c\u3002\u9019\u610f\u5473\u8457\u7121\u8ad6\u51fd\u6578\u662f\u6b63\u5e38\u8fd4\u56de\u9084\u662f\u56e0\u70ba\u932f\u8aa4\u800c\u63d0\u524d\u9000\u51fa\uff0c<code>defer<\/code> \u8a9e\u53e5\u90fd\u6703\u88ab\u57f7\u884c\u3002<\/p>\n<pre><code>package main\n\nimport \"fmt\"\n\nfunc main() {\n    defer fmt.Println(\"\u9019\u53e5\u8a71\u6703\u5728\u51fd\u6578\u7d50\u675f\u6642\u57f7\u884c\")\n    fmt.Println(\"\u9019\u53e5\u8a71\u6703\u5148\u57f7\u884c\")\n}\n<\/code><\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u7576 <code>main<\/code> \u51fd\u6578\u7d50\u675f\u6642\uff0c<code>defer<\/code> \u8a9e\u53e5\u6703\u88ab\u57f7\u884c\uff0c\u8f38\u51fa\u7d50\u679c\u5c07\u662f\uff1a<\/p>\n<pre><code>\u9019\u53e5\u8a71\u6703\u5148\u57f7\u884c\n\u9019\u53e5\u8a71\u6703\u5728\u51fd\u6578\u7d50\u675f\u6642\u57f7\u884c\n<\/code><\/pre>\n<h2 id=\"2-defer-%e7%9a%84%e5%9f%b7%e8%a1%8c%e9%a0%86%e5%ba%8f-JQSBnaFAjx\">2. defer \u7684\u57f7\u884c\u9806\u5e8f<\/h2>\n<p>\u5982\u679c\u5728\u4e00\u500b\u51fd\u6578\u4e2d\u6709\u591a\u500b <code>defer<\/code> \u8a9e\u53e5\uff0c\u5b83\u5011\u7684\u57f7\u884c\u9806\u5e8f\u662f\u5f8c\u9032\u5148\u51fa\uff08LIFO\uff09\u3002\u9019\u610f\u5473\u8457\u6700\u5f8c\u4e00\u500b\u88ab\u5b9a\u7fa9\u7684 <code>defer<\/code> \u8a9e\u53e5\u6703\u6700\u5148\u57f7\u884c\u3002<\/p>\n<pre><code>package main\n\nimport \"fmt\"\n\nfunc main() {\n    defer fmt.Println(\"\u7b2c\u4e00\u500b defer\")\n    defer fmt.Println(\"\u7b2c\u4e8c\u500b defer\")\n    defer fmt.Println(\"\u7b2c\u4e09\u500b defer\")\n}\n<\/code><\/pre>\n<p>\u57f7\u884c\u7d50\u679c\u5c07\u662f\uff1a<\/p>\n<pre><code>\u7b2c\u4e09\u500b defer\n\u7b2c\u4e8c\u500b defer\n\u7b2c\u4e00\u500b defer\n<\/code><\/pre>\n<h2 id=\"3-defer-%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-JQSBnaFAjx\">3. defer \u7684\u61c9\u7528\u5834\u666f<\/h2>\n<h3 id=\"3-1-%e8%b3%87%e6%ba%90%e7%ae%a1%e7%90%86-JQSBnaFAjx\">3.1 \u8cc7\u6e90\u7ba1\u7406<\/h3>\n<p>\u5728\u8655\u7406\u6587\u4ef6\u3001\u7db2\u7d61\u9023\u63a5\u6216\u5176\u4ed6\u9700\u8981\u6e05\u7406\u7684\u8cc7\u6e90\u6642\uff0c<code>defer<\/code> \u662f\u4e00\u500b\u7406\u60f3\u7684\u9078\u64c7\u3002\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u5373\u4f7f\u5728\u767c\u751f\u932f\u8aa4\u7684\u60c5\u6cc1\u4e0b\uff0c\u8cc7\u6e90\u4e5f\u80fd\u88ab\u6b63\u78ba\u91cb\u653e\u3002<\/p>\n<pre><code>package main\n\nimport (\n    \"fmt\"\n    \"os\"\n)\n\nfunc main() {\n    file, err := os.Open(\"example.txt\")\n    if err != nil {\n        fmt.Println(err)\n        return\n    }\n    defer file.Close() \/\/ \u78ba\u4fdd\u6587\u4ef6\u5728\u51fd\u6578\u7d50\u675f\u6642\u95dc\u9589\n\n    \/\/ \u9032\u884c\u6587\u4ef6\u64cd\u4f5c\n    fmt.Println(\"\u6587\u4ef6\u64cd\u4f5c\u6210\u529f\")\n}\n<\/code><\/pre>\n<h3 id=\"3-2-%e9%8c%af%e8%aa%a4%e8%99%95%e7%90%86-JQSBnaFAjx\">3.2 \u932f\u8aa4\u8655\u7406<\/h3>\n<p>\u5728\u932f\u8aa4\u8655\u7406\u65b9\u9762\uff0c<code>defer<\/code> \u53ef\u4ee5\u7528\u4f86\u8a18\u9304\u932f\u8aa4\u4fe1\u606f\u6216\u9032\u884c\u6e05\u7406\u5de5\u4f5c\uff0c\u9019\u6a23\u5373\u4f7f\u5728\u767c\u751f\u932f\u8aa4\u6642\u4e5f\u80fd\u4fdd\u6301\u4ee3\u78bc\u7684\u6574\u6f54\u3002<\/p>\n<pre><code>package main\n\nimport \"fmt\"\n\nfunc riskyFunction() {\n    defer func() {\n        if r := recover(); r != nil {\n            fmt.Println(\"\u6355\u7372\u5230\u932f\u8aa4:\", r)\n        }\n    }()\n    panic(\"\u767c\u751f\u4e86\u4e00\u500b\u932f\u8aa4\")\n}\n\nfunc main() {\n    riskyFunction()\n}\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>defer<\/code> \u7528\u65bc\u6355\u7372\u53ef\u80fd\u767c\u751f\u7684\u932f\u8aa4\uff0c\u5f9e\u800c\u907f\u514d\u7a0b\u5e8f\u5d29\u6f70\u3002<\/p>\n<h2 id=\"4-%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-JQSBnaFAjx\">4. \u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u96d6\u7136 <code>defer<\/code> \u63d0\u4f9b\u4e86\u8a31\u591a\u4fbf\u5229\uff0c\u4f46\u4e5f\u6709\u4e00\u4e9b\u9700\u8981\u6ce8\u610f\u7684\u5730\u65b9\uff1a<\/p>\n<ul>\n<li><strong>\u6027\u80fd\u5f71\u97ff\uff1a<\/strong>\u6bcf\u6b21\u8abf\u7528 <code>defer<\/code> \u90fd\u6703\u6709\u4e00\u5b9a\u7684\u6027\u80fd\u958b\u92b7\uff0c\u56e0\u6b64\u5728\u6027\u80fd\u654f\u611f\u7684\u4ee3\u78bc\u4e2d\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/li>\n<li><strong>\u8b8a\u91cf\u4f5c\u7528\u57df\uff1a<\/strong>\u5728 <code>defer<\/code> \u8a9e\u53e5\u4e2d\u4f7f\u7528\u7684\u8b8a\u91cf\u6703\u5728\u5b9a\u7fa9\u6642\u88ab\u6355\u7372\uff0c\u800c\u4e0d\u662f\u5728\u57f7\u884c\u6642\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-JQSBnaFAjx\">\u7e3d\u7d50<\/h2>\n<p>Go \u8a9e\u8a00\u4e2d\u7684 <code>defer<\/code> \u95dc\u9375\u5b57\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7ba1\u7406\u8cc7\u6e90\u548c\u8655\u7406\u932f\u8aa4\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528 <code>defer<\/code>\uff0c\u53ef\u4ee5\u4f7f\u4ee3\u78bc\u66f4\u52a0\u7c21\u6f54\u548c\u6613\u65bc\u7dad\u8b77\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u904b\u884c\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u60a8\u7684\u61c9\u7528\u5728\u7a69\u5b9a\u7684\u74b0\u5883\u4e2d\u904b\u884c\u3002\u4e86\u89e3\u66f4\u591a\u95dc\u65bc <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3 Go \u8a9e\u8a00\u4e2d\u7684 defer \u8a9e\u53e5\uff0c\u5b78\u7fd2\u5982\u4f55\u5ef6\u9072\u57f7\u884c\u51fd\u6578\uff0c\u63d0\u5347\u7a0b\u5f0f\u78bc\u53ef\u8b80\u6027\u8207\u8cc7\u6e90\u7ba1\u7406\u6548\u7387\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4924],"tags":[],"class_list":["post-57798","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/57798","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=57798"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/57798\/revisions"}],"predecessor-version":[{"id":57799,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/57798\/revisions\/57799"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=57798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=57798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=57798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}