{"id":1503,"date":"2025-03-10T00:40:19","date_gmt":"2025-03-09T16:40:19","guid":{"rendered":"http:\/\/codermr.com\/?p=1503"},"modified":"2025-03-10T00:40:19","modified_gmt":"2025-03-09T16:40:19","slug":"c%e5%9f%ba%e7%a1%80%e7%9f%a5%e8%af%86%e6%b1%87%e6%80%bb%e4%b8%83%ef%bc%9a%e6%b3%9b%e5%9e%8b%e3%80%81%e5%8c%bf%e5%90%8d%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"http:\/\/codermr.com\/index.php\/2025\/03\/10\/c%e5%9f%ba%e7%a1%80%e7%9f%a5%e8%af%86%e6%b1%87%e6%80%bb%e4%b8%83%ef%bc%9a%e6%b3%9b%e5%9e%8b%e3%80%81%e5%8c%bf%e5%90%8d%e6%96%b9%e6%b3%95\/","title":{"rendered":"C#\u57fa\u7840\u77e5\u8bc6\u6c47\u603b\u4e03\uff1a\u6cdb\u578b\u3001\u533f\u540d\u65b9\u6cd5"},"content":{"rendered":"\n

C# Generics<\/h1>\n\n\n\n

Introduction to the C# generics \u3010\u6cdb\u578b\u65b9\u6cd5\u3011<\/h2>\n\n\n\n

C# generics allow you to write code that works with more than one type<\/mark><\/strong>. By using generics, you can write code with placeholders for types<\/mark><\/strong> and then provide the actual types when using the code.<\/p>\n\n\n\n

Generics introduces the concept of type parameters<\/em><\/strong> to .NET. Generics make it possible to design classes and methods<\/em><\/strong> that(\u6307”classes and methods<\/em><\/strong>“) defer the specification of one or more type parameters<\/mark><\/strong> until you use the class or method in your code. \u3010\u6cdb\u578b\u5f15\u5165\u4e86\u7c7b\u578b\u53c2\u6570\u7684\u6982\u5ff5\u3002\u6cdb\u578b\u4f7f\u8bbe\u8ba1\u7c7b\u548c\u65b9\u6cd5\u6210\u4e3a\u53ef\u80fd\uff0c\u8fd9\u4e9b\u7c7b\u548c\u65b9\u6cd5\u53ef\u4ee5\u63a8\u8fdf\u4e00\u4e2a\u6216\u591a\u4e2a\u7c7b\u578b\u53c2\u6570\u7684\u89c4\u8303\uff0c\u76f4\u5230\u60a8\u5728\u4ee3\u7801\u4e2d\u4f7f\u7528\u8be5\u7c7b\u6216\u65b9\u6cd5\u3002\u3011<\/p>\n\n\n\n

Suppose you need to write a method that swaps the values of two integer<\/a> variables. To do that, you can define a method called SwapInt()<\/code> that accepts two integer parameters like this:<\/p>\n\n\n\n

static void SwapInt(ref int a, ref int b)\n{\n    int temp = a;\n        a = b;\n        b = temp;\n}<\/code><\/pre>\n\n\n\n
Later, you want to swap the values of two\u00a0string<\/a>\u00a0variables. In this case, you need to define a new method that swaps the strings:<\/p>\n\n\n\n
static void SwapString(ref string a, ref string b)\n{\n    string temp = a;\n           a = b;\n           b = temp;\n}<\/code><\/pre>\n\n\n\n
Both SwapInt()<\/code> and SwapString()<\/code> methods have the same logic except for the types of the variables that they deal with.<\/p>\n\n\n\n
Imagine that you need to swap values of two variables of a new type e.g., float<\/a>, you need to define a new method for each new type. As the result, you\u2019ll have lots of Swap*<\/code> methods with the same logic.<\/p>\n\n\n\n
To resolve this, you can create a generic method that swaps values of variables of any type like this:<\/p>\n\n\n\n
static void Swap<T>(ref T a, ref T b)\n{\n    T temp = a;\n      a = b;\n      b = temp;\n}<\/code><\/pre>\n\n\n\n
In this\u00a0Swap()<\/code>\u00a0method, instead of using a specific type, we use the placeholder T for the type.<\/p>\n\n\n\n
When using the\u00a0Swap()<\/code>\u00a0method, you can specify the specific type. For example:<\/p>\n\n\n\n
int x = 10, y = 20; Swap<int>(ref x, ref y);<\/p>\n\n\n\n
In this example, we specify the\u00a0int<\/code>\u00a0type inside the angle brackets (<><\/code>) that follows the method name. Since the types of\u00a0x<\/code>\u00a0and\u00a0y<\/code>\u00a0are\u00a0int<\/code>, you can make the method call short like this:<\/p>\n\n\n\n
int x = 10, y = 20;\n\nSwap(ref x, ref y);<\/code><\/pre>\n\n\n\n
Summary<\/h2>\n\n\n\n