C#回调函数使用一例

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Threading;

namespace CSharp_002_回调机制

{

    public partial class frmMain : Form

    {

        //定义回调

        private delegate void SetProgressBar2ValueCallBack(int value);

        //声明回调

        private SetProgressBar2ValueCallBack setProgressBar2ValueCallBack;

        public frmMain()

        {

            InitializeComponent();

        }

        private void btnStart_Click(object sender, EventArgs e)

        {

            //初始化回调

            setProgressBar2ValueCallBack = new SetProgressBar2ValueCallBack(SetProgressBar2ValueMethod);

            Thread progressBar2Thread = new Thread(SetProgressBar2Value);

            progressBar2Thread.Start();

            for (int i = 0; i <= 100; i++)

            {

                Application.DoEvents();

                Thread.Sleep(50);

                pgProgressBar1.Value = i;

            }

        }

        //设置进度条2的值 的线程

        private void SetProgressBar2Value()

        {

            for (int i = 0; i <= 100;i++ )

            {

                Thread.Sleep(50);

                pgProgressBar2.Invoke(setProgressBar2ValueCallBack, i);

            }

        }

        //设置进度条2的值 被委托的方法

        private void SetProgressBar2ValueMethod(int value)

        {

            pgProgressBar2.Value = value;

        }

    }//end class frmMain

}