匿名函数是一个“内联”语句或表达式,可在需要委托类型的任何地方使用。
可以使用匿名函数来初始化命名委托,或传递命名委托(而不是命名委托类型)作为方法参数。
C# 中委托的发展
通常,针对 .NET Framework 版本 3.5 及更高版本的应用程序应使用 Lambda 表达式。
下面的示例演示了从 C# 1.0 到 C# 3.0 委托创建过程的发展:
class Test { delegate void TestDelegate(string s); static void M(string s) { Console.WriteLine(s); } static void Main(string[] args) { // Original delegate syntax required // initialization with a named method. TestDelegate testDelA = new TestDelegate(M); // C# 2.0: A delegate can be initialized with // inline code, called an "anonymous method." This // method takes a string as an input parameter. TestDelegate testDelB = delegate(string s) { Console.WriteLine(s); }; // C# 3.0. A delegate can be initialized with // a lambda expression. The lambda also takes a string // as an input parameter (x). The type of x is inferred by the compiler. TestDelegate testDelC = (x) => { Console.WriteLine(x); }; // Invoke the delegates. testDelA("Hello. My name is M and I write lines."); testDelB("That's nothing. I'm anonymous and "); testDelC("I'm a famous author."); // Keep console window open in debug mode. Console.WriteLine("Press any key to exit."); Console.ReadKey(); } } /* Output: Hello. My name is M and I write lines. That's nothing. I'm anonymous and I'm a famous author. Press any key to exit. */