{"id":289,"date":"2022-06-29T17:06:27","date_gmt":"2022-06-29T09:06:27","guid":{"rendered":"https:\/\/www.fengjijiao.cn\/?p=289"},"modified":"2022-06-29T17:06:28","modified_gmt":"2022-06-29T09:06:28","slug":"c%e5%a7%94%e6%89%98%ef%bc%88delegate%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.fengjijiao.cn\/?p=289","title":{"rendered":"C#\u59d4\u6258\uff08Delegate\uff09"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>using System;\r\nusing System.IO;\r\n\r\ndelegate int NumberChanger(int n);\r\n\r\nnamespace ConsoleApp1\r\n{\r\n    class Program\r\n    {\r\n        static int num = 10;\r\n        public static int AddNum(int p)\r\n        {\r\n            num += p;\r\n            return num;\r\n        }\r\n        public static int MultiNum(int q)\r\n        {\r\n            num *= q;\r\n            return num;\r\n        }\r\n        public static int getNum()\r\n        {\r\n            return num;\r\n        }\r\n        static void Main(string&#91;] args)\r\n        {\r\n            \/\/C#\u59d4\u6258\uff08Delegate\uff09\r\n            \/*\r\n             * C#\u4e2d\u7684\u59d4\u6258\u7c7b\u4f3c\u4e8eC\u6216C++\u4e2d\u51fd\u6570\u7684\u6307\u9488\u3002\u59d4\u6258\uff08Delegate\uff09\u662f\u5b58\u6709\u5bf9\u67d0\u4e2a\u65b9\u6cd5\u7684\u5f15\u7528\u7684\u4e00\u79cd\u5f15\u7528\u7c7b\u578b\u53d8\u91cf\u3002\u5f15\u7528\u53ef\u5728\u8fd0\u884c\u65f6\u88ab\u6539\u53d8\u3002\r\n             * \u59d4\u6258\uff08Delegate\uff09\u7279\u522b\u7528\u4e8e\u5b9e\u73b0\u4e8b\u4ef6\u548c\u56de\u8c03\u65b9\u6cd5\u3002\u6240\u6709\u7684\u59d4\u6258\uff08Delegate\uff09\u90fd\u6d3e\u751f\u81eaSystem.Delegate\u7c7b\u3002\r\n             * \r\n             *\/\r\n            \/\/\u58f0\u660e\u59d4\u6258\uff08Delegate\uff09\r\n            \/*\r\n             * \u59d4\u6258\u58f0\u660e\u51b3\u5b9a\u4e86\u53ef\u7531\u8be5\u59d4\u6258\u5f15\u7528\u7684\u65b9\u6cd5\u3002\u59d4\u6258\u53ef\u6307\u5411\u4e00\u4e2a\u4e0e\u5176\u5177\u6709\u76f8\u540c\u6807\u7b7e\u7684\u65b9\u6cd5\u3002\r\n             * \u4f8b\u5982\uff0c\u5047\u5982\u6709\u4e00\u4e2a\u59d4\u6258\uff1a\r\n             * public delegate int MyDelegate(string s);\r\n             * \u4e0a\u9762\u7684\u59d4\u6258\u53ef\u88ab\u7528\u4e8e\u5f15\u7528\u4efb\u4f55\u4e00\u4e2a\u5e26\u6709\u4e00\u4e2a\u5355\u4e00\u7684string\u53c2\u6570\u7684\u65b9\u6cd5\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2aint\u7c7b\u578b\u53d8\u91cf\u3002\r\n             * \u58f0\u660e\u8bed\u6cd5\uff1a\r\n             * delegate &lt;return type> &lt;delegate name> &lt;parameter list>;\r\n             * \r\n             *\/\r\n            \/\/\u5b9e\u4f8b\u5316\u59d4\u6258\uff08Delegate\uff09\r\n            \/*\r\n             * \u4e00\u65e6\u58f0\u660e\u4e86\u59d4\u6258\u7c7b\u578b\uff0c\u59d4\u6258\u5bf9\u8c61\u5fc5\u987b\u4f7f\u7528new\u5173\u952e\u5b57\u6765\u521b\u5efa\uff0c\u4e14\u4e0e\u4e00\u4e2a\u7279\u5b9a\u7684\u65b9\u6cd5\u6709\u5173\u3002\u5f53\u521b\u5efa\u59d4\u6258\u65f6\uff0c\u4f20\u9012\u5230new\u8bed\u53e5\u7684\u53c2\u6570\u5c31\u50cf\u65b9\u6cd5\u8c03\u7528\u4e00\u6837\u4e66\u5199\uff0c\u4f46\u662f\u4e0d\u5e26\u6709\u53c2\u6570\u3002\r\n             * public delegate void printString(string s);\r\n             * ...\r\n             * printString ps1 = new printString(writeToScreen);\r\n             * printString ps2 = new printString(writeToFile);\r\n             * \r\n             * \u4e0b\u9762\u7684\u5b9e\u4f8b\u6f14\u793a\u4e86\u59d4\u6258\u7684\u58f0\u660e\u3001\u5b9e\u4f8b\u5316\u548c\u4f7f\u7528\uff0c\u8be5\u59d4\u6258\u53ef\u7528\u4e8e\u5f15\u7528\u5e26\u6709\u4e00\u4e2a\u6574\u578b\u53c2\u6570\u7684\u65b9\u6cd5\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2a\u6574\u578b\u503c\u3002\r\n             * \r\n             *\/\r\n            \/\/\u521b\u5efa\u59d4\u6258\u5b9e\u4f8b\r\n            NumberChanger nc1 = new NumberChanger(AddNum);\r\n            NumberChanger nc2 = new NumberChanger(MultiNum);\r\n            \/\/\u4f7f\u7528\u59d4\u6258\u5bf9\u8c61\u8c03\u7528\u65b9\u6cd5\r\n            nc1(25);\/\/35\r\n            Console.WriteLine(\"Value of Num: {0}\", getNum());\r\n            nc2(5);\/\/175\r\n            Console.WriteLine(\"Value of Num: {0}\", getNum());\r\n\r\n            \/\/\u59d4\u6258\u7684\u591a\u64ad(Multicasting of a Delegate)\r\n            \/*\r\n             * \u59d4\u6258\u5bf9\u8c61\u53ef\u4f7f\u7528\"+\"\u8fd0\u7b97\u7b26\u8fdb\u884c\u5408\u5e76\u3002\u4e00\u4e2a\u5408\u5e76\u59d4\u6258\u8c03\u7528\u5b83\u6240\u5408\u5e76\u7684\u4e24\u4e2a\u59d4\u6258\u3002\u53ea\u6709\u76f8\u540c\u7c7b\u578b\u7684\u59d4\u6258\u53ef\u88ab\u5408\u5e76\u3002\r\n             * \"-\"\u8fd0\u7b97\u7b26\u53ef\u7528\u5408\u5e76\u59d4\u6258\u4e2d\u79fb\u9664\u7ec4\u4ef6\u59d4\u6258\u3002\r\n             * \u4f7f\u7528\u8fd9\u4e2a\u6709\u7528\u7684\u7279\u70b9\uff0c\u4f60\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u59d4\u6258\u88ab\u8c03\u7528\u65f6\u8981\u8c03\u7528\u7684\u65b9\u6cd5\u7684\u8c03\u7528\u5217\u8868\u3002\u8fd9\u88ab\u79f0\u4e3a\u59d4\u6258\u7684\u591a\u64ad\uff08multicasting\uff09\uff0c\u4e5f\u53eb\u7ec4\u64ad\u3002\r\n             *\/\r\n            \/\/\u521b\u5efa\u59d4\u6258\u5b9e\u4f8b\r\n            NumberChanger nc;\r\n            nc = nc1;\/\/+n\r\n            nc += nc2;\/\/*n\r\n            \/\/\u8c03\u7528\u591a\u64ad\r\n            nc(5);\/\/(175 + 5) * 5 = 900\r\n            Console.WriteLine(\"Value of Num: {0}\", getNum());\r\n\r\n            \/\/\u59d4\u6258\u7684\u7528\u9014\r\n            \/* \u59d4\u6258printString\u53ef\u7528\u4e8e\u5f15\u7528\u5e26\u6709\u4e00\u4e2a\u5b57\u7b26\u4e32\u4f5c\u4e3a\u8f93\u5165\u7684\u65b9\u6cd5\uff0c\u5e76\u4e0d\u8fd4\u56de\u4efb\u4f55\u4e1c\u897f\u3002\r\n             * \u6211\u4eec\u4f7f\u7528\u8fd9\u4e2a\u59d4\u6258\u6765\u8c03\u75282\u4e2a\u65b9\u6cd5\uff0c\u7b2c\u4e00\u4e2a\u628a\u5b57\u7b26\u4e32\u6253\u5370\u5230\u63a7\u5236\u53f0\uff0c\u7b2c\u4e8c\u4e2a\u628a\u5b57\u7b26\u4e32\u6253\u5370\u5230\u6587\u4ef6\u3002\r\n             * \r\n             *\/\r\n            PrintString.printString ps1 = new PrintString.printString(PrintString.WriteToScreen);\r\n            PrintString.printString ps2 = new PrintString.printString(PrintString.WriteToFile);\r\n            PrintString.sendString(ps1);\r\n            PrintString.sendString(ps2);\r\n\r\n            Console.ReadKey();\r\n        }\r\n    }\r\n\r\n    class PrintString\r\n    {\r\n        static FileStream fs;\r\n        static StreamWriter sw;\r\n        \/\/\u59d4\u6258\u58f0\u660e\r\n        public delegate void printString(string s);\r\n        \/\/\u8be5\u65b9\u6cd5\u6253\u5370\u5230\u63a7\u5236\u53f0\r\n        public static void WriteToScreen(string str)\r\n        {\r\n            Console.WriteLine(\"The String is: {0}\", str);\r\n        }\r\n        \/\/\u8be5\u65b9\u6cd5\u6253\u5370\u5230\u6587\u4ef6\r\n        public static void WriteToFile(string s)\r\n        {\r\n            fs = new FileStream(\"c:\\\\message.txt\", FileMode.Append, FileAccess.Write);\r\n            sw = new StreamWriter(fs);\r\n            sw.WriteLine(s);\r\n            sw.Flush();\r\n            sw.Close();\r\n            fs.Close();\r\n        }\r\n        \/\/\u8be5\u65b9\u6cd5\u628a\u59d4\u6258\u4f5c\u4e3a\u53c2\u6570\uff0c\u5e76\u4f7f\u7528\u5b83\u8c03\u7528\u65b9\u6cd5\r\n        public static void sendString(printString ps)\r\n        {\r\n            ps(\"Hello World\");\r\n        }\r\n\r\n    }\r\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[19],"tags":[],"_links":{"self":[{"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/posts\/289"}],"collection":[{"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=289"}],"version-history":[{"count":1,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/posts\/289\/revisions"}],"predecessor-version":[{"id":290,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=\/wp\/v2\/posts\/289\/revisions\/290"}],"wp:attachment":[{"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=289"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=289"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fengjijiao.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=289"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}