Mega Code Archive

 
Categories / VB.Net / WPF
 

Show a Continuous Progress Bar While Processing on a Background Thread

<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" Height="100" Width="200">     <StackPanel>         <ProgressBar Name="progressBar"/>         <Button Name="button" Click="button_Click">Start</Button>     </StackPanel> </Window> //File:Window.xaml.vb Imports System.ComponentModel Imports System.Threading Imports System.Windows Imports System.Windows.Input Namespace WpfApplication1   Public Partial Class Window1     Inherits Window     Private worker As New BackgroundWorker()     Public Sub New()       InitializeComponent()       worker.WorkerSupportsCancellation = True       AddHandler worker.DoWork, New DoWorkEventHandler(AddressOf worker_DoWork)       AddHandler worker.RunWorkerCompleted, New RunWorkerCompletedEventHandler(AddressOf worker_RunWorkerCompleted)     End Sub     Private Sub button_Click(sender As Object, e As RoutedEventArgs)       If Not worker.IsBusy Then         Me.Cursor = Cursors.Wait         progressBar.IsIndeterminate = True         button.Content = "Cancel"         worker.RunWorkerAsync()       Else         worker.CancelAsync()       End If     End Sub     Private Sub worker_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs)       Me.Cursor = Cursors.Arrow       If e.[Error] IsNot Nothing Then         MessageBox.Show(e.[Error].Message)       End If       button.Content = "Start"       progressBar.IsIndeterminate = False     End Sub     Private Sub worker_DoWork(sender As Object, e As DoWorkEventArgs)       For i As Integer = 1 To 100         If worker.CancellationPending Then           Exit For         End If         Thread.Sleep(50)       Next     End Sub   End Class End Namespace