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，

 

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！