using System.Windows;
using System.Threading;
using System.ComponentModel;

namespace WpfApp1
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {

        private BackgroundWorker bw = new BackgroundWorker(); //声明BackgroundWorker对象

        public MainWindow()
        {
            InitializeComponent();

            InitBW();

        }

        /// <summary>
        /// 初始化
        /// </summary>
        private void InitBW()
        {
            //属性
            bw.WorkerReportsProgress = true;
            bw.WorkerSupportsCancellation = true;

            //事件
            bw.DoWork += Bw_DoWork;
            bw.ProgressChanged += Bw_ProgressChanged;
            bw.RunWorkerCompleted += Bw_RunWorkerCompleted;
        }

        private void Bw_DoWork(object sender, DoWorkEventArgs e)
        {
            //string a = e.Argument as string;

            for (int i = 0; i < 100; i++)
            {
                //当接收到取消指令时
                if (bw.CancellationPending)
                {
                    e.Cancel = true;
                    return;
                }
                else
                {
                    bw.ReportProgress(i, "Working"); //调用ReportProgress方法
                    Thread.Sleep(10);
                }
            }
        }

        private void Bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            pro1.Value = e.ProgressPercentage;
            txt1.Text = e.ProgressPercentage.ToString() + "%";
            txt2.Text = e.UserState.ToString();
        }

        private void Bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            //是否出现错误
            if (e.Error != null)
            {
                MessageBox.Show(e.Error.ToString());
                return;
            }

            //是否为用户取消
            if (e.Cancelled)
            {
                txt1.Text = "终止";
                txt2.Text = "Worked";
            }
            else
            {
                txt1.Text = "完毕";
                txt2.Text = "Worked";
            }
        }


        //启动
        private void btnStart_Click(object sender, RoutedEventArgs e)
        {
            //是否正在执行一个异步操作
            if (bw.IsBusy)
                return;

            pro1.Maximum = 100;
            btnStart.IsEnabled = false;
            btnStop.IsEnabled = true;
            bw.RunWorkerAsync("hello world");

        }

        //停止
        private void btnStop_Click(object sender, RoutedEventArgs e)
        {
            bw.CancelAsync();
            btnStart.IsEnabled = true;
            btnStop.IsEnabled = false;
        }

    }
}

private void Form1_Load(object sender, EventArgs e)
{
      this.backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
       this.textBox1.Text = "UI";
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Delegate3
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();
        }
        
        private void button1_Click(object sender, EventArgs e)
        {
            //启动异步调用方法
            //调用RunWorkerAsync()方法，会触发DoWork事件
            this.backgroundWorker2.RunWorkerAsync();
        }

        private void backgroundWorker2_DoWork(object sender, DoWorkEventArgs e)
        {
            backgroundWorker2.WorkerReportsProgress = true;
            for (int i = 1; i <= 100; i++)
            {
                //这里判断一下是否用户要求取消后台进行，并可以尽早退出。
                //可以通过调用CancelAsync方法设置CancellationPending的值为false
                if (backgroundWorker2.CancellationPending)
                {
                    backgroundWorker2.ReportProgress(i, String.Format("{0}%,操作被用户申请中断", i));
                }

                //调用 ReportProgress 方法，会触发ProgressChanged事件
                backgroundWorker2.ReportProgress(i, String.Format("{0}%", i));
                System.Threading.Thread.Sleep(10);
            }
        }

        private void backgroundWorker2_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            this.progressBar1.Value = e.ProgressPercentage;
            this.label1.Text = e.UserState.ToString();
            this.label1.Update();
        }

        private void backgroundWorker2_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            //这是结束后做的事情
            MessageBox.Show("完成");
        }
    }
}