深入委托与多播委托的详解

using system;
using system.collections.generic;
using system.text;
namespace consoleapplication1
{
    class 简单的委托实例
    {
        public static double area(double val)
        {
            return val * 2;
        }
        public static double scare(double val)
        {
            return val * val;
        }
    }
    class test
    {
        public delegate double delegatetest(double dd);
        static void main()
        {
            //实例化了个委托数组,（一旦定义了委托类,就可以实例化它的实例）
            delegatetest[] operations =
                {
                    //说明了委托的一种方式,把方法组合到数组
                  new delegatetest(简单的委托实例.area),
                  new delegatetest(简单的委托实例.scare)
                };
            for (int i = 0; i < operations.length; i++)
            {
                console.writeline("using operations[{0}]", i);
                test mytest = new test();
                //把委托传递给processdelagate()这个方法,operations[0]可以理解成delegatetest operations =new delegatetest(简单的委托实例.area);调用processdelagate这个方法的时候operations代理的方法是简单的委托实例.area
                mytest.processdelagate(operations[i], 12.0);
                mytest.processdelagate(operations[i], 2.0);
                console.writeline();
            }
        }
        //把委托作为一个参数传递到processdelagate()第一个参数中
        void processdelagate(delegatetest action, double d)
        {
            double result = action(d);
            console.writeline("提供的值是{0},结果是{1}", d, result);
        }
    }
}

using system;
using system.collections.generic;
using system.text;
namespace consoleapplication1
{
    //如果要多次调用这个方法,那么就要多次调用这个委托,委托包含多个方法,这个种委托就是多播委托！
    class 多播委托
    {
        //用的是void没有返回值
        public delegate void delagetetest(double val);
        static void main()
        {
            //多播委托中添加2个方法
            delagetetest mytest = new delagetetest(test.area);
            mytest += new delagetetest(test.scare);
            //下面的代码跟上面的3行代码是等价的
            //delagetetest mytest;
            //delagetetest test1 = new delagetetest(test.area);
            //delagetetest test2 = new delagetetest(test.scare);
            //mytest = test1 + test2;
            多播委托 多 = new 多播委托();
            多.opreation(mytest, 2.0);
            多.opreation(mytest, 12.0);
        }
        void opreation(delagetetest action, double d)
        {
            action(d);
        }
    }
    class test
    {
        public static void area(double val)
        {
            console.writeline(val * 2);
        }
        public static void scare(double val)
        {
            console.writeline(val * val);
        }
    }
}