Create a Background Worker Thread in XAML

Posted on by coder
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//File:Window.xaml.cs

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

namespace WpfApplication1
{
public partial class Window1 : Window
{
private readonly BackgroundWorker worker;

public Window1()
{
InitializeComponent();
worker = this.FindResource(“backgroundWorker”) as BackgroundWorker;
}

private void button_Click(object sender, RoutedEventArgs e)
{
if(!worker.IsBusy)
{
this.Cursor = Cursors.Wait;
worker.RunWorkerAsync();
button.Content = “Cancel”;
}else{
worker.CancelAsync();
}
}

private void BackgroundWorker_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
for(int i = 1; i <= 100; i++) { if(worker.CancellationPending) break; Thread.Sleep(100); worker.ReportProgress(i); } } private void BackgroundWorker_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e) { this.Cursor = Cursors.Arrow; Console.WriteLine(e.Error.Message); button.Content = "Start"; } private void BackgroundWorker_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; } } } [/csharp]

Show a ProgressBar While Processing on a Background Thread

Posted on by coder
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//File:Window.xaml.cs
using System.ComponentModel;
using System.Threading;
using System.Windows;
using System.Windows.Input;

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

public Window1()
{
InitializeComponent();
worker.WorkerReportsProgress = true;
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
worker.ProgressChanged += worker_ProgressChanged;
}

private void button_Click(object sender, RoutedEventArgs e)
{
worker.RunWorkerAsync();
this.Cursor = Cursors.Wait;
button.IsEnabled = false;
}

private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
this.Cursor = Cursors.Arrow;
if(e.Error != null)
MessageBox.Show(e.Error.Message);
button.IsEnabled = true;
}
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
for(int i = 1; i <= 100; i++) { Thread.Sleep(100); worker.ReportProgress(i); } } private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; } } } [/csharp]

Use BackgroundWorker to run task at background

Posted on by coder
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//File:Window.xaml.cs
using System.ComponentModel;
using System.Threading;
using System.Windows;
using System.Windows.Input;

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

public Window1()
{
InitializeComponent();
worker.WorkerReportsProgress = true;
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
worker.ProgressChanged += worker_ProgressChanged;
}

private void button_Click(object sender, RoutedEventArgs e)
{
worker.RunWorkerAsync();
this.Cursor = Cursors.Wait;
button.IsEnabled = false;
}

private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
this.Cursor = Cursors.Arrow;
if(e.Error != null)
MessageBox.Show(e.Error.Message);
button.IsEnabled = true;
}
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
for(int i = 1; i <= 100; i++) { Thread.Sleep(100); worker.ReportProgress(i); } } private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; } } } [/csharp]

A Cancellable ProgressBar While Processing on a Background Thread

Posted on by coder
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//File:Window.xaml.cs
using System.ComponentModel;
using System.Threading;
using System.Windows;
using System.Windows.Input;

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

public Window1()
{
InitializeComponent();
worker.WorkerReportsProgress = true;
worker.WorkerSupportsCancellation = true;
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
worker.ProgressChanged += worker_ProgressChanged;
}

private void button_Click(object sender, RoutedEventArgs e){
if(!worker.IsBusy)
{
this.Cursor = Cursors.Wait;
worker.RunWorkerAsync();
button.Content = “Cancel”;
}else{
worker.CancelAsync();
}
}

private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
this.Cursor = Cursors.Arrow;
if(e.Cancelled)
{
MessageBox.Show(“Operation was canceled”);
}
else if(e.Error != null)
{
MessageBox.Show(e.Error.Message);
}

button.Content = “Start”;
}

private void worker_DoWork(object sender, DoWorkEventArgs e)
{
for(int i = 1; i <= 100; i++) { if(worker.CancellationPending) { e.Cancel = true; return; } Thread.Sleep(100); worker.ReportProgress(i); } } private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; } } } [/csharp]

Show a Continuous Progress Bar While Processing on a Background Thread

Posted on by coder
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//File:Window.xaml.cs
using System.ComponentModel;
using System.Threading;
using System.Windows;
using System.Windows.Input;

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

public Window1()
{
InitializeComponent();
worker.WorkerSupportsCancellation = true;
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
}

private void button_Click(object sender, RoutedEventArgs e)
{
if (!worker.IsBusy)
{
this.Cursor = Cursors.Wait;
progressBar.IsIndeterminate = true;
button.Content = “Cancel”;
worker.RunWorkerAsync();
}
else
{
worker.CancelAsync();
}
}

private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
this.Cursor = Cursors.Arrow;

if (e.Error != null)
{
MessageBox.Show(e.Error.Message);
}

button.Content = “Start”;
progressBar.IsIndeterminate = false;
}

private void worker_DoWork(object sender, DoWorkEventArgs e){
for (int i = 1; i <= 100; i++) { if (worker.CancellationPending) break; Thread.Sleep(50); } } } } [/csharp]

Using a BackgroundWorker: progress changed and completed

Posted on by coder
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//File:Window.xaml.cs
using System;
using System.Collections.Generic;
using System.Text;
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.Shapes;
using System.ComponentModel;
using System.Threading;

namespace BackgroundWorkerExample
{
partial class MyWindow : Window
{
BackgroundWorker bw = new BackgroundWorker();

public MyWindow()
{
bw.DoWork += new DoWorkEventHandler(bw_DoWork);
bw.ProgressChanged += bw_ProgressChanged;
bw.RunWorkerCompleted += bw_RunWorkerCompleted;
bw.WorkerReportsProgress = true;
bw.RunWorkerAsync();
}

void bw_DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 0; i < 10; ++i) { int percent = i * 10; bw.ReportProgress(percent); Thread.Sleep(1000); } } void bw_ProgressChanged(object sender, ProgressChangedEventArgs e) { this.Title = "Working: " + e.ProgressPercentage + "%"; } void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { this.Title = "Finished"; } } } [/csharp]

Unblock Thread with BackgroundWorker

Posted on by coder
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<Window x:Class="WPFThreading.UnblockThreadTwo"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="UI Thread Blocker" Height="275" Width="225">
  <Border Width="200" Height="225" BorderBrush="Black" 
    BorderThickness="1" Margin="4">
    <StackPanel>

      <Label>Simulate Long-Running Process</Label>
      <Button Name="button1" Click="button1_click">Go to sleep</Button>

      <Label>Will I respond?</Label>
      <Button Name="button2" Click="button2_click">Try Me</Button>

      <Label>Output Messages</Label>
      <TextBox Name="textbox1"/>

      <Label/>

      <StackPanel Orientation="Horizontal">
        <Label>UI thread:</Label>
        <Label Name="UIThreadLabel"></Label>
      </StackPanel>

      <StackPanel Orientation="Horizontal">
        <Label>BG thread:</Label>
        <Label Name="BackgroundThreadLabel"></Label>
      </StackPanel>

    </StackPanel>
  </Border>
</Window>
//File:Window.xaml.cs

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

namespace WPFThreading
{
  
  public partial class UnblockThreadTwo : System.Windows.Window
  {

    private BackgroundWorker worker;

    private delegate void SimpleDelegate();

    public UnblockThreadTwo()
    {
      InitializeComponent();

      this.UIThreadLabel.Content = this.Dispatcher.Thread.ManagedThreadId;
      this.BackgroundThreadLabel.Content = "N/A";
    }

    private void button1_click(object sender, RoutedEventArgs e)
    {
      worker = new BackgroundWorker();

      worker.DoWork += new DoWorkEventHandler(RunOnBGThread);

      worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BGThreadWorkDone);

      worker.RunWorkerAsync();
    }

    private void button2_click(object sender, RoutedEventArgs e)
    {
      this.textbox1.Text = "Hello WPF";
    }

    private void LongRunningProcess()
    {

      SimpleDelegate del1 = delegate(){ this.BackgroundThreadLabel.Content = Thread.CurrentThread.ManagedThreadId; };
      this.Dispatcher.BeginInvoke(DispatcherPriority.Send, del1);

      Thread.Sleep(5000);
    }

    private void RunOnBGThread(object sender, DoWorkEventArgs e)
    {
      LongRunningProcess();
    }

    private void BGThreadWorkDone(object sender,RunWorkerCompletedEventArgs e)
    {
       this.textbox1.Text = "Done Sleeping..";
    }

  }
}