WPF window not closing

Question

could you tell a beginner why this small WPF-application is not closing as intended after the WorkflowTerminated event fires? The used workflow just terminates immediately. (using a WPF application, .Net Framework 3.5)

public partial class MainWindow : Window
{
    private WorkflowRuntime wfRuntime = new WorkflowRuntime();

    public MainWindow()
    {
        InitializeComponent();

        wfRuntime.WorkflowTerminated += (se, ev) => this.Close(); // this doesn't close the window
        wfRuntime.WorkflowCompleted += (se, ev) => this.Close();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        WorkflowInstance launcherWorkflow = wfRuntime.CreateWorkflow(typeof(InstallerWorkflow));

        launcherWorkflow.Start();
    }
}

When setting a breakpoint in the terminated-eventhandler, is it even executed? — ZoolWay, Apr 14 '11 at 07:28
Good question by the way, this haunted me before and was very hard to figure, +1 — Teoman Soygul, Apr 14 '11 at 07:49

Teoman Soygul · Accepted Answer · 2011-04-14T07:43:15.220

6

Probably because the callback is on another thread. A basic workaround is to terminate the application altogether using Environment.Exit(1);

To call the close function on the UI thread you should use:

wfRuntime.WorkflowTerminated += (se, ev) => {
    // call back to the window to do the UI-manipulation
    this.Dispatcher.Invoke(DispatcherPriority.Normal, new Action(delegate() 
    {
       this.Close();
    }));
};

edited Apr 14 '11 at 07:43

answered Apr 14 '11 at 07:31

Teoman Soygul

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My Application object doesn't have an exit() method. Propably because it is an WPF application? I tried Application.Current.Shutdown() which doesn't help. Still doesn't close... – nabulke Apr 14 '11 at 07:35
How could I post the terminate event to the right thread (GUI thread)? – nabulke Apr 14 '11 at 07:37
Environment.Exit() works, the application is closing. But it feels kind of dirty ;-) Is there a cleaner way, to reach my goal (i.e. handling the event in the right thread, so Close() works as intended?). Nevertheless thanks for your help so far! – nabulke Apr 14 '11 at 07:40
2

Yep I updated the answer to callback the Close() method on the UI thread so UI windows closes right. – Teoman Soygul Apr 14 '11 at 07:41
Just fixed a typo by the way (forgot the second closing parenthesis before semicolon) – Teoman Soygul Apr 14 '11 at 07:47
Thanks Teoman. Now it works as intended. Looks kind of complicated right now though. At least for me as a beginner. – nabulke Apr 14 '11 at 07:51
Yes updating the UI thread (main thread mostly) from a background tread is a bit complicating at first but is quite logical once you get the hand of threading.. Been there done that:) – Teoman Soygul Apr 14 '11 at 07:53

WPF window not closing

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