private void btnSend_Click(object sender, RoutedEventArgs e) { Button obj=(Button)sender; obj.Content="Cancel"; SendImage send = new SendImage(); Thread t = new Thread(send.Image); t.Start(); //run separate thread.(very long, 9 hours) //so dont wait. //but the button should be reset to obj.Content="Send" //Can I do this? } I want the button to be reset to "Send" (after completion of thread). But form should not wait. Is this possible?
You can do this more elegantly using the BackgroundWorker class.
XAML for the Button:
<Button x:Name="btnGo" Content="Send" Click="btnGo_Click"></Button> Code :
private BackgroundWorker _worker; public MainWindow() { InitializeComponent(); _worker = new BackgroundWorker(); _worker.WorkerSupportsCancellation = true; _worker.WorkerReportsProgress = true; } private void btnGo_Click(object sender, RoutedEventArgs e) { _worker.RunWorkerCompleted += delegate(object completedSender, RunWorkerCompletedEventArgs completedArgs) { Dispatcher.BeginInvoke((Action)(() => { btnGo.Content = "Send"; })); }; _worker.DoWork += delegate(object s, DoWorkEventArgs args) { Dispatcher.BeginInvoke((Action)(() => { btnGo.Content = "Cancel"; })); SendImage sendImage = args.Argument as SendImage; if (sendImage == null) return; var count = 0; while (!_worker.CancellationPending) { Dispatcher.BeginInvoke((Action)(() => { btnGo.Content = string.Format("Cancel {0} {1}", sendImage.Name, count); })); Thread.Sleep(100); count++; } }; if (_worker.IsBusy) { _worker.CancelAsync(); } else { _worker.RunWorkerAsync(new SendImage() { Name = "Test" }); } } 
Make the Button a member of your Window/UserControl class (by giving it a Name in XAML). When the thread eventually finishes, do this before returning from the thread method:
myButton.Dispatcher.BeginInvoke( (Action)(() => myButton.Content = "Send")); 