委托：组合委托的例子

using  System;
using  System.Collections;
using  System.ComponentModel;
using  System.Data;
using  System.Drawing;
using  System.Web;
using  System.Web.SessionState;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.HtmlControls;

namespace  AspNetTest.Common
{
    /**//// <summary>
    /// Degalete_Math_Op 的摘要说明。
    /// </summary>
    public class Define_Degalete_MathOp : System.Web.UI.Page
    {
        private void Page_Load(object sender, System.EventArgs e)
        {
            MathOp mathOp = new MathOp(1,0);
            mathOp.opDelegate = new MathOp.OpDelegate(OperateFunc.Add);
            Response.Write("加：" + mathOp.Operate() + "<br>");
            mathOp.opDelegate = new MathOp.OpDelegate(OperateFunc.Subtract);
            Response.Write("减：" + mathOp.Operate() + "<br>");
            mathOp.opDelegate = new MathOp.OpDelegate(OperateFunc.Multiply);
            Response.Write("乘：" + mathOp.Operate() + "<br>");
            mathOp.opDelegate = new MathOp.OpDelegate(OperateFunc.Divide);
            Response.Write("除：" + mathOp.Operate() + "<br>");
            Response.Write("<hr>");
            
            //改变组合委托的参数
            mathOp.opDelegate = null;
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Add);
            mathOp.op2 = 1;
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Subtract);
            Response.Write("改变第二个组合委托的参数后，减操作的值为：" + mathOp.Operate() + "<br>");                        
            Response.Write("<hr>");
            
            mathOp.opDelegate = null;
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Add);
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Subtract);
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Multiply);
            mathOp.opDelegate += new MathOp.OpDelegate(OperateFunc.Divide);
            //以下输出的是 0,即最后一个Divide的return值
            Response.Write("组合委托的return值是：" + mathOp.Operate() + "<br>");
            Response.Write("<hr>");
            
            mathOp.opResponseDelegate = null;
            mathOp.opResponseDelegate += new MathOp.OpResponseDelegate(OperateFunc.ResponseAdd);
            mathOp.opResponseDelegate += new MathOp.OpResponseDelegate(OperateFunc.ResponseSubtract);
            mathOp.opResponseDelegate += new MathOp.OpResponseDelegate(OperateFunc.ResponseMultiply);
            mathOp.opResponseDelegate += new MathOp.OpResponseDelegate(OperateFunc.ResponseDivide);    
            Response.Write("组合委托的所有执行输出值是：<br>");    
            mathOp.ResponseOperate();    
        }
        
        public class MathOp
        {
            public MathOp(int op1, int op2)
            {
                this.op1 = op1;
                this.op2 = op2;
            }
            public delegate int OpDelegate(int op1, int op2);
            public delegate void OpResponseDelegate(int op1, int op2);
            public OpDelegate opDelegate;
            public OpResponseDelegate opResponseDelegate;
            public int Operate()
            {
                if(opDelegate != null)
                {
                    int result = opDelegate(this.op1, this.op2);
                    return result;
                }
                else
                {
                    throw new NullReferenceException();
                }
            }
            public void ResponseOperate()
            {
                if(opResponseDelegate != null)
                {
                    opResponseDelegate(this.op1, this.op2);
                }
                else
                {
                    throw new NullReferenceException();
                }
            }
            private int op1;
            public int op2;
        }
        
        public class OperateFunc
        {
            public static int Add(int op1, int op2)
            {
                return (int)op1+op2;
            }
            public static int Subtract(int op1, int op2)
            {
                return (int)op1-op2;
            }
            public static int Multiply(int op1, int op2)
            {
                return (int)op1*op2;
            }
            //表示整除
            public static int Divide(int op1, int op2)
            {
                return op2==0 ? 0 : (int)op1/op2;
            }
            
            
            public static void ResponseAdd(int op1, int op2)
            {
                int result = (int)op1+op2;
                HttpContext.Current.Response.Write("加：" + result + "<br>");
            }
            public static void ResponseSubtract(int op1, int op2)
            {
                int result = (int)op1-op2;
                HttpContext.Current.Response.Write("减：" + result + "<br>");                
            }
            public static void ResponseMultiply(int op1, int op2)
            {
                int result = (int)op1*op2;
                HttpContext.Current.Response.Write("乘：" + result + "<br>");
            }
            //表示整除
            public static void ResponseDivide(int op1, int op2)
            {
                int result = (op2==0 ? 0 : (int)op1/op2);
                HttpContext.Current.Response.Write("除：" + result + "<br>");
            }
        }
        
        
        
        
        
        
        
        
        Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {    
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion
    }
}