Support the Cancellation of a Background Worker Thread : BackgroundWorker « Windows Presentation Foundation « C# / CSharp Tutorial






<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF" Width="230" Height="148" >
    <StackPanel>
        <Button Click="StartStop_Click" Name="btnStartStop" Height="34">Start</Button>
        <TextBlock Name="txtBiggestPrime" Margin="5" />
    </StackPanel>
</Window>
//File:Window.xaml.cs

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


namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        private BackgroundWorker worker = new BackgroundWorker();

        private long from = 2;
        private long to = 2000;
        private long biggestPrime;

        public Window1(): base()
        {
            InitializeComponent();
            worker.WorkerSupportsCancellation = true;
            worker.DoWork += new DoWorkEventHandler(worker_DoWork);
            worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
        }
        private void StartStop_Click(object sender, RoutedEventArgs e)
        {
            if(!worker.IsBusy)
            {
                worker.RunWorkerAsync();
                btnStartStop.Content = "Cancel";
                txtBiggestPrime.Text = string.Empty;
            }
            else
            {
                worker.CancelAsync();
            }
        }

        private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if(e.Cancelled)
            {
                MessageBox.Show("Operation was canceled");
            }

            btnStartStop.Content = "Start";
            txtBiggestPrime.Text = biggestPrime.ToString();
        }

        private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            for(long current = from; current <= to; current++)
            {
                if(worker.CancellationPending)
                {
                    e.Cancel = true;
                    return;
                }
                biggestPrime = current;
            }
        }
    }
}
WPF Support The Cancellation Of A Background Worker Thread








24.152.BackgroundWorker
24.152.1.Execute a Method Asynchronously Using a Background Worker ThreadExecute a Method Asynchronously Using a Background Worker Thread
24.152.2.Track the Progress of a Background Worker ThreadTrack the Progress of a Background Worker Thread
24.152.3.Support the Cancellation of a Background Worker ThreadSupport the Cancellation of a Background Worker Thread
24.152.4.Create a Background Worker Thread in XAMLCreate a Background Worker Thread in XAML
24.152.5.Show a ProgressBar While Processing on a Background ThreadShow a ProgressBar While Processing on a Background Thread
24.152.6.Use BackgroundWorker to run task at backgroundUse BackgroundWorker to run task at background
24.152.7.A Cancellable ProgressBar While Processing on a Background ThreadA Cancellable ProgressBar While Processing on a Background Thread
24.152.8.Show a Continuous Progress Bar While Processing on a Background ThreadShow a Continuous Progress Bar While Processing on a Background Thread
24.152.9.Using a BackgroundWorker: progress changed and completedUsing a BackgroundWorker: progress changed and completed
24.152.10.Unblock Thread with BackgroundWorkerUnblock Thread with BackgroundWorker