{"id":205807,"date":"2025-06-12T09:24:31","date_gmt":"2025-06-12T01:24:31","guid":{"rendered":"https:\/\/server.hk\/cnblog\/205807\/"},"modified":"2025-06-12T09:24:31","modified_gmt":"2025-06-12T01:24:31","slug":"golang-%e5%87%bd%e6%95%b0%ef%bc%9a%e7%94%a8-withvalue-%e4%bc%a0%e9%80%92%e4%b8%8a%e4%b8%8b%e6%96%87%e6%95%b0%e6%8d%ae","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/205807\/","title":{"rendered":"Golang \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e"},"content":{"rendered":"<p>\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u6211\u4eec\u8981\u52aa\u529b\u5b66\u4e60\u5566\uff01\u4eca\u5929\u6211\u7ed9\u5927\u5bb6\u5e26\u6765<br \/>\n<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u300aGOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\u300b<\/span>\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4e0b\u6587\u4e2d\u7684\u5185\u5bb9\u6211\u4eec\u4e3b\u8981\u4f1a\u6d89\u53ca\u5230<br \/>\n<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\"><\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u5728\u9605\u8bfb\u672c\u6587\u8fc7\u7a0b\u4e2d\u6709\u9047\u5230\u4e0d\u6e05\u695a\u7684\u5730\u65b9\uff0c\u6b22\u8fce\u7559\u8a00\u5440\uff01\u6211\u4eec\u4e00\u8d77\u8ba8\u8bba\uff0c\u4e00\u8d77\u5b66\u4e60\uff01,\u5728 Go \u4e2d\uff0c\u4f7f\u7528 WithValue \u51fd\u6570\u53ef\u4ee5\u5411 context.Context \u6dfb\u52a0\u952e\u503c\u5bf9\uff0c\u5b9e\u73b0\u4e0a\u4e0b\u6587\u6570\u636e\u5728\u51fd\u6570\u8c03\u7528\u94fe\u4e2d\u7684\u4f20\u9012\u3002\u5177\u4f53\u6b65\u9aa4\u5982\u4e0b\uff1a\u521b\u5efa\u4e00\u4e2a\u6839 context\u3002\u4f7f\u7528 WithValue \u6dfb\u52a0\u952e\u503c\u5bf9\u5230 context\u3002\u5728\u9700\u8981\u65f6\u901a\u8fc7 Value \u65b9\u6cd5\u4ece\u4e0a\u4e0b\u6587\u4e2d\u83b7\u53d6\u6570\u636e\u3002,<br \/>\n<img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241027\/1730005591671dca57623ce.jpg\" class=\"aligncenter\">,\u5728 Go \u4e2d\uff0c[<br \/>\n<code>context.Context<\/code>](https:\/\/pkg.go.dev\/context#Context) \u7c7b\u578b\u7528\u4e8e\u5728\u51fd\u6570\u8c03\u7528\u94fe\u4e2d\u4f20\u9012\u4e0a\u4e0b\u6587\u4fe1\u606f\u3002[<br \/>\n<code>context.WithValue<\/code>](https:\/\/pkg.go.dev\/context#WithValue) \u51fd\u6570\u5141\u8bb8\u6211\u4eec\u5411\u4e0a\u4e0b\u6587\u4e2d\u6dfb\u52a0\u81ea\u5b9a\u4e49\u952e\u503c\u5bf9\uff0c\u4ece\u800c\u53ef\u4ee5\u5728\u9700\u8981\u65f6\u4f7f\u7528\u8fd9\u4e9b\u6570\u636e\u3002,\u5176\u4e2d\uff1a,\u8ba9\u6211\u4eec\u901a\u8fc7\u4e00\u4e2a\u793a\u4f8b\u6765\u4e86\u89e3\u5982\u4f55\u5728\u51fd\u6570\u4e2d\u4f7f\u7528<br \/>\n<code>WithValue<\/code> \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\uff1a,\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u4f7f\u7528<br \/>\n<code>WithValue<\/code> \u5728\u6839 context \u4e2d\u6dfb\u52a0\u4e86\u4e00\u500b\u952e\u503c\u5bf9\uff0c\u5176\u4e2d\u952e\u662f &#8220;user_id&#8221;\uff0c\u503c\u662f 1\u3002\u7576\u6211\u5011\u8abf\u7528<br \/>\n<code>getUserInfo<\/code> \u6642\uff0c\u5b83\u5f9e\u4e0a\u4e0b\u6587\u4e2d\u63d0\u53d6\u7528\u6236 ID\uff0c\u4e26\u4f7f\u7528\u5b83\u67e5\u8a62\u8cc7\u6599\u5eab\u7372\u53d6\u7528\u6236\u8cc7\u8a0a\u3002,\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aGOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~GOLANG\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03GOLANG\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01,\u8fc7\u5ea6\u4f7f\u7528<br \/>\n<code>WithValue<\/code> \u53ef\u80fd\u4f1a\u5728\u4e0a\u4e0b\u6587\u4e2d\u4ea7\u751f\u5927\u91cf\u7684\u6570\u636e\u3002\u56e0\u6b64\uff0c\u5efa\u8bae\u4ec5\u5728\u7edd\u5bf9\u5fc5\u8981\u65f6\u4f7f\u7528\u5b83\u3002,\u4f20\u9012\u7ed9<br \/>\n<code>WithValue<\/code> \u7684\u952e\u5e94\u8be5\u8db3\u591f\u72ec\u7279\uff0c\u4ee5\u907f\u514d\u4e0e\u5176\u4ed6\u4e0a\u4e0b\u6587\u4e2d\u4f7f\u7528\u7684\u952e\u51b2\u7a81\u3002,\u4e0a\u4e0b\u6587\u4e2d\u7684\u6570\u636e\u662f\u4e0d\u53ef\u5909\u7684\uff0c\u8fd9\u610f\u5473\u7740\u4f60\u6dfb\u52a0\u7684\u6570\u636e\u4e0d\u80fd\u88ab\u4fee\u6539\u3002,<br \/>\n<code>key<\/code> \u662f\u6570\u636e\u7684\u952e\uff0c\u53ef\u4ee5\u662f\u4efb\u4f55\u7c7b\u578b\u7684\u503c\uff08\u901a\u5e38\u662f\u5b57\u7b26\u4e32\uff09\u3002,<br \/>\n<code>ctx<\/code> \u662f\u8981\u6dfb\u52a0\u6570\u636e\u7684\u4e0a\u4e0b\u6587\u3002,<br \/>\n<code>val<\/code> \u662f\u8981\u5b58\u50a8\u5728\u4e0a\u4e0b\u6587\u4e2d\u7684\u6570\u636e\u503c\u3002,\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u6211\u4eec\u8981\u52aa\u529b\u5b66\u4e60\u5566\uff01\u4eca\u5929\u6211\u7ed9\u5927\u5bb6\u5e26\u6765<br \/>\n<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u300aGOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\u300b<\/span>\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4e0b\u6587\u4e2d\u7684\u5185\u5bb9\u6211\u4eec\u4e3b\u8981\u4f1a\u6d89\u53ca\u5230<br \/>\n<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\"><\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u5728\u9605\u8bfb\u672c\u6587\u8fc7\u7a0b\u4e2d\u6709\u9047\u5230\u4e0d\u6e05\u695a\u7684\u5730\u65b9\uff0c\u6b22\u8fce\u7559\u8a00\u5440\uff01\u6211\u4eec\u4e00\u8d77\u8ba8\u8bba\uff0c\u4e00\u8d77\u5b66\u4e60\uff01,<br \/>\n<b><\/b> <\/p>\n<p>\u5f53\u524d\u4f4d\u7f6e\uff1a <span>&gt;<\/span>  <span>&gt;<\/span>  <span>&gt;<\/span>  <span>&gt;<\/span> <span>GOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e<\/span><\/p>\n<h1>GOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e<\/h1>\n<p><span>2024-10-27 13:06:46<\/span><br \/>\n<span><i><\/i>0\u6d4f\u89c8<\/span><br \/>\n<span style=\"cursor: pointer\"><i><\/i>\u6536\u85cf<\/span> <\/p>\n<p>\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u6211\u4eec\u8981\u52aa\u529b\u5b66\u4e60\u5566\uff01\u4eca\u5929\u6211\u7ed9\u5927\u5bb6\u5e26\u6765<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u300aGOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\u300b<\/span>\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4e0b\u6587\u4e2d\u7684\u5185\u5bb9\u6211\u4eec\u4e3b\u8981\u4f1a\u6d89\u53ca\u5230<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\"><\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u5728\u9605\u8bfb\u672c\u6587\u8fc7\u7a0b\u4e2d\u6709\u9047\u5230\u4e0d\u6e05\u695a\u7684\u5730\u65b9\uff0c\u6b22\u8fce\u7559\u8a00\u5440\uff01\u6211\u4eec\u4e00\u8d77\u8ba8\u8bba\uff0c\u4e00\u8d77\u5b66\u4e60\uff01<\/p>\n<p>\u5728 Go \u4e2d\uff0c\u4f7f\u7528 WithValue \u51fd\u6570\u53ef\u4ee5\u5411 context.Context \u6dfb\u52a0\u952e\u503c\u5bf9\uff0c\u5b9e\u73b0\u4e0a\u4e0b\u6587\u6570\u636e\u5728\u51fd\u6570\u8c03\u7528\u94fe\u4e2d\u7684\u4f20\u9012\u3002\u5177\u4f53\u6b65\u9aa4\u5982\u4e0b\uff1a\u521b\u5efa\u4e00\u4e2a\u6839 context\u3002\u4f7f\u7528 WithValue \u6dfb\u52a0\u952e\u503c\u5bf9\u5230 context\u3002\u5728\u9700\u8981\u65f6\u901a\u8fc7 Value \u65b9\u6cd5\u4ece\u4e0a\u4e0b\u6587\u4e2d\u83b7\u53d6\u6570\u636e\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241027\/1730005591671dca57623ce.jpg\" class=\"aligncenter\"><\/p>\n<h2>GOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e<\/h2>\n<p>\u5728 Go \u4e2d\uff0c[<code>context.Context<\/code>](https:\/\/pkg.go.dev\/context#Context) \u7c7b\u578b\u7528\u4e8e\u5728\u51fd\u6570\u8c03\u7528\u94fe\u4e2d\u4f20\u9012\u4e0a\u4e0b\u6587\u4fe1\u606f\u3002[<code>context.WithValue<\/code>](https:\/\/pkg.go.dev\/context#WithValue) \u51fd\u6570\u5141\u8bb8\u6211\u4eec\u5411\u4e0a\u4e0b\u6587\u4e2d\u6dfb\u52a0\u81ea\u5b9a\u4e49\u952e\u503c\u5bf9\uff0c\u4ece\u800c\u53ef\u4ee5\u5728\u9700\u8981\u65f6\u4f7f\u7528\u8fd9\u4e9b\u6570\u636e\u3002<\/p>\n<h3>\u8bed\u6cd5<\/h3>\n<pre>func WithValue(ctx Context, key, val interface{}) Context<\/pre>\n<p>\u5176\u4e2d\uff1a<\/p>\n<ul>\n<li><code>ctx<\/code> \u662f\u8981\u6dfb\u52a0\u6570\u636e\u7684\u4e0a\u4e0b\u6587\u3002<\/li>\n<li><code>key<\/code> \u662f\u6570\u636e\u7684\u952e\uff0c\u53ef\u4ee5\u662f\u4efb\u4f55\u7c7b\u578b\u7684\u503c\uff08\u901a\u5e38\u662f\u5b57\u7b26\u4e32\uff09\u3002<\/li>\n<li><code>val<\/code> \u662f\u8981\u5b58\u50a8\u5728\u4e0a\u4e0b\u6587\u4e2d\u7684\u6570\u636e\u503c\u3002<\/li>\n<\/ul>\n<h3>\u5b9e\u6218\u6848\u4f8b<\/h3>\n<p>\u8ba9\u6211\u4eec\u901a\u8fc7\u4e00\u4e2a\u793a\u4f8b\u6765\u4e86\u89e3\u5982\u4f55\u5728\u51fd\u6570\u4e2d\u4f7f\u7528 <code>WithValue<\/code> \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\uff1a<\/p>\n<pre>package main\n\nimport (\n    \"context\"\n    \"fmt\"\n    \"log\"\n)\n\n\/\/ \u7528\u6236\u8cc7\u6599\u7684\u578b\u614b\ntype User struct {\n    ID int\n    Name string\n}\n\nfunc main() {\n    \/\/ \u5275\u5efa\u4e00\u500b\u6839 context\n    ctx := context.Background()\n\n    \/\/ \u4f7f\u7528 WithValue \u70ba\u7528\u6236\u8cc7\u6599\u6dfb\u52a0\u4e0a\u4e0b\u6587\u8cc7\u6599\n    \/\/ key \u70ba \"user_id\"\uff0cval \u70ba 1\n    ctx = context.WithValue(ctx, \"user_id\", 1)\n\n    \/\/ \u8abf\u7528\u51fd\u5f0f getUserInfo\uff0c\u4e26\u5728\u5176\u4e2d\u8a2a\u554f\u4e0a\u4e0b\u6587\u8cc7\u6599\n    userInfo, err := getUserInfo(ctx)\n    if err != nil {\n        log.Fatal(err)\n    }\n\n    fmt.Printf(\"\u7528\u6236\u8cc7\u8a0a\uff1aID: %d, \u540d\u7a31: %s\\n\", userInfo.ID, userInfo.Name)\n}\n\n\/\/ getUserInfo \u51fd\u6578\uff0c\u5b83\u5f9e\u4e0a\u4e0b\u6587\u8cc7\u6599\u4e2d\u63d0\u53d6\u7528\u6236 ID \u4e26\u4f7f\u7528\u5b83\u67e5\u8a62\u8cc7\u6599\u5eab\u4f86\u7372\u53d6\u7528\u6236\u8cc7\u8a0a\nfunc getUserInfo(ctx context.Context) (*User, error) {\n    \/\/ \u5f9e\u4e0a\u4e0b\u6587\u4e2d\u7372\u53d6\u7528\u6236 ID\n    userID, ok := ctx.Value(\"user_id\").(int)\n    if !ok {\n        return nil, fmt.Errorf(\"\u4e0a\u4e0b\u6587\u8cc7\u6599\u4e2d\u6c92\u6709\u4f7f\u7528\u8005 ID\")\n    }\n\n    \/\/ \u67e5\u8a62\u8cc7\u6599\u5eab\u4ee5\u7372\u53d6\u7528\u6236\u8cc7\u8a0a\n    \/\/ \u6b64\u8655\u7701\u7565\u67e5\u8a62\u8cc7\u6599\u5eab\u7684\u4ee3\u78bc\n\n    return &amp;User{\n        ID: userID,\n        Name: \"John Doe\",\n    }, nil\n}<\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u4f7f\u7528 <code>WithValue<\/code> \u5728\u6839 context \u4e2d\u6dfb\u52a0\u4e86\u4e00\u500b\u952e\u503c\u5bf9\uff0c\u5176\u4e2d\u952e\u662f &#8220;user_id&#8221;\uff0c\u503c\u662f 1\u3002\u7576\u6211\u5011\u8abf\u7528 <code>getUserInfo<\/code> \u6642\uff0c\u5b83\u5f9e\u4e0a\u4e0b\u6587\u4e2d\u63d0\u53d6\u7528\u6236 ID\uff0c\u4e26\u4f7f\u7528\u5b83\u67e5\u8a62\u8cc7\u6599\u5eab\u7372\u53d6\u7528\u6236\u8cc7\u8a0a\u3002<\/p>\n<h3>\u6ce8\u610f\uff1a<\/h3>\n<ul>\n<li>\u4e0a\u4e0b\u6587\u4e2d\u7684\u6570\u636e\u662f\u4e0d\u53ef\u5909\u7684\uff0c\u8fd9\u610f\u5473\u7740\u4f60\u6dfb\u52a0\u7684\u6570\u636e\u4e0d\u80fd\u88ab\u4fee\u6539\u3002<\/li>\n<li>\u4f20\u9012\u7ed9 <code>WithValue<\/code> \u7684\u952e\u5e94\u8be5\u8db3\u591f\u72ec\u7279\uff0c\u4ee5\u907f\u514d\u4e0e\u5176\u4ed6\u4e0a\u4e0b\u6587\u4e2d\u4f7f\u7528\u7684\u952e\u51b2\u7a81\u3002<\/li>\n<li>\u8fc7\u5ea6\u4f7f\u7528 <code>WithValue<\/code> \u53ef\u80fd\u4f1a\u5728\u4e0a\u4e0b\u6587\u4e2d\u4ea7\u751f\u5927\u91cf\u7684\u6570\u636e\u3002\u56e0\u6b64\uff0c\u5efa\u8bae\u4ec5\u5728\u7edd\u5bf9\u5fc5\u8981\u65f6\u4f7f\u7528\u5b83\u3002<\/li>\n<\/ul>\n<p>\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aGOLANG \u51fd\u6570\uff1a\u7528 WithValue \u4f20\u9012\u4e0a\u4e0b\u6587\u6570\u636e\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~GOLANG\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03GOLANG\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<dd>\n   PHP\u51fd\u6570\u5982\u4f55\u5904\u7406\u7f3a\u5931\u53c2\u6570\n <\/dd>\n<\/dl>\n<dl>\n<dt>\n <\/dt>\n<dd>\n   \u51fd\u6570\u6d4b\u8bd5\u7684 GOLANG \u6700\u4f73\u5b9e\u8df5\n <\/dd>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u6211\u4eec\u8981\u52aa\u529b\u5b66\u4e60\u5566\uff01\u4eca&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-205807","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/205807","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=205807"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/205807\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=205807"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=205807"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=205807"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}