委托小案例

// Declare delegate -- defines required signature:
delegate double MathAction(double num);

class DelegateTest
{
??? // Regular method that matches signature:
??? static double Double(double input)
??? {
??????? return input * 2;
??? }

??? static void Main()
??? {
??????? // Instantiate delegate with named method:
??????? MathAction ma = Double;

??????? // Invoke delegate ma:
??????? double multByTwo = ma(4.5);
??????? Console.WriteLine(multByTwo);

??????? // Instantiate delegate with anonymous method:
??????? MathAction ma2 = delegate(double input)
??????? {
??????????? return input * input;
??????? };

??????? double square = ma2(5);
??????? Console.WriteLine(square);

??????? // Instantiate delegate with lambda expression
??????? MathAction ma3 = s => s * s * s;
??????? double cube = ma3(4.375);

??????? Console.WriteLine(cube);
??? }
}


?this.button2.Click += new System.EventHandler(this.button2_Click);

?this.button2.Click += new System.EventHandler(this.button1_Click);

这也是委托的一种，也可以给它委托多个事件，

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委托： 个人理解 就是 委托别人做事情，一件事可以委托多个人，可以得到多种结果，也可以没结果，也就是委托可以委托多个方法，可以有返回值，也可以没返回值！?

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