用于异步的BackgroundWorker

XAML代码：

<Window x:Class="backgroundtest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="160" Width="237">

    <StackPanel Height="100" Width="196">
        <ProgressBar Name="progressBar" Height="20" Width="200" Margin="10" />
        <Button Name="btnProcess" Width="100" Click="btnProcess_click" Margin="5">process</Button>
        <Button Name="btncancel" Width="100" Click="btnCancel_Click" Margin="5">cancel</Button>

    </StackPanel>
</Window>

后台代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace backgroundtest
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        BackgroundWorker bgWorker=new BackgroundWorker();
        public MainWindow()
        {
            InitializeComponent();
            bgWorker.WorkerReportsProgress = true;
            bgWorker.WorkerSupportsCancellation = true;
            bgWorker.DoWork += DoWork_Handle;
            bgWorker.ProgressChanged += ProgressChanged_Handle;
            bgWorker.RunWorkerCompleted += RunWorkerCompleted_Handler;
        }

        private void btnProcess_click(object sender, RoutedEventArgs e)
        {
            if (!bgWorker.IsBusy)
            {
                bgWorker.RunWorkerAsync();
            }
        }

        private void ProgressChanged_Handle(Object sender,ProgressChangedEventArgs args)
        {
            progressBar.Value = args.ProgressPercentage;
        }

        private void DoWork_Handle(object sender, DoWorkEventArgs args)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            for (int i = 0; i < 10; i++)
            {
                if (worker.CancellationPending)
                {
                    args.Cancel = true;
                    break;
                }
                else
                {
                    worker.ReportProgress(i*10);
                    Thread.Sleep(500);
                }
            }

        }

        private void RunWorkerCompleted_Handler(object sender, RunWorkerCompletedEventArgs args)
        {
            progressBar.Value = 0;
            if (args.Cancelled)
            {
                MessageBox.Show("process was cancelled.", "process cancelled");
            }
            else
            {
                MessageBox.Show("process completed normally.", "process completed");
            }
        }

        private void btnCancel_Click(object sender, RoutedEventArgs e)
        {
            bgWorker.CancelAsync();
        }
    }

}

用于异步的BackgroundWorker