Terminating a thread on WPF window close

Question

I created a small wpf window application. The MainWindow has a button that when pressed, a thread is created and begins to execute. Below is my code for xaml:

<Window x:Class="Tester.MainWindow"
    ...
    Title="MainWindow" Height="150" Width="300" Closed="OnWindowclose">
<Grid>
    <Button Content="Start" HorizontalAlignment="Left" Margin="42,47,0,0" VerticalAlignment="Top" Width="75" Click="Start_Click"/>
</Grid>

Here is what my .cs code looks like:

public partial class MainWindow : Window
{
    private Thread t1;

    public MainWindow()
    {
        InitializeComponent();
    }

    private void OnWindowclose(object sender, EventArgs e)
    {
        System.Windows.Application.Current.Shutdown();
    }

    private void Start_Click(object sender, RoutedEventArgs e)
    {
        move = true;
        t1 = new System.Threading.Thread(KeepMoving);
        t1.Start();
    }


    private void KeepMoving()
    {
    // my code
    }
}

Now, my problem is when I close the MainWindow using its close button. I can still see that the application hasn't stopped. I have tried a couple of things after reading some stackoverflow posts and created an event OnWindowClose and called application shutdown. But that doesn't seem to work as expected.

I don't want to call Thread.Abort() as it throws an exception and forums suggest not to go for it. This post seems similar to what I am looking to achieve, but still I did not get how to use it to stop thread in close window.

I am fairly new to threads so I am not sure what can I can do to fix the issue. Any help would be appreciated.

Thanks.

score 4 · Accepted Answer · answered Aug 17 '18 at 18:05

4

Make all threads run in the background

t1 = new System.Threading.Thread(KeepMoving);
t1.IsBackground = true;
t1.Start();

Add Environment Closing to Form Closing

Environment.Exit(Environment.ExitCode);

Full Code

public partial class MainWindow : Window
{
    private Thread t1;

    public MainWindow()
    {
        InitializeComponent();
    }

    private void OnWindowclose(object sender, EventArgs e)
    {
        Environment.Exit(Environment.ExitCode); // Prevent memory leak
        // System.Windows.Application.Current.Shutdown(); // Not sure if needed
    }

    private void Start_Click(object sender, RoutedEventArgs e)
    {
        move = true;
        t1 = new System.Threading.Thread(KeepMoving);
        t1.IsBackground = true; // Run in background
        t1.Start();
    }


    private void KeepMoving()
    {
    // my code
    }
}

answered Aug 17 '18 at 18:05

Impurity

1,037
2
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31

environment.exit has the same effect as thread.abort – Steve Aug 17 '18 at 18:08
3

I actually think making them background might be enough – Impurity Aug 17 '18 at 18:11
1

Okay so setting IsBackground property makes all the threads dependent on parent window thread right?? And thus closing the main window causes the dependent threads to close as well. – Naphstor Aug 17 '18 at 18:18
Yessir, see this example/explanation https://learn.microsoft.com/en-us/dotnet/api/system.threading.thread.isbackground?redirectedfrom=MSDN&view=netframework-4.7.2#System_Threading_Thread_IsBackground – Impurity Aug 17 '18 at 18:20

Terminating a thread on WPF window close

1 Answers1