C#•2y ago

Windows crashing the program when attempting to reopen windows after having been closed once already

My MainWindow has some buttons which open other windows also in the project through a app.view_name.ShowDialog(); command. If I click the button to open the problem windows and then close it, if I attempt to reopen by clicking the button once again I get this exception:

System.InvalidOperationException: 'Cannot set Visibility or call Show, ShowDialog, or WindowInteropHelper.EnsureHandle after a Window has closed.'

. Of the four buttons in this MainWindow two of them are experiencing this crash, while the others aren't for some reason. Please tell me if there's any code you would like to see as I am more than happy to provide it, but there's just so much code that could be relevant to my inexperienced eyes I didn't know what to post.

11 Replies

HimmDawg•2y ago

The exception message says it all: "Cannot set Visibility or call Show, ShowDialog, or WindowInteropHelper.EnsureHandle after a Window has closed." How do you open those windows?

Jimmacle•2y ago

it sounds like one instance of the dialog is sitting around in a singleton/static class if you're trying to show a new window you should create a new window

GipperOP•2y ago

If I have a window called say "thingA", in the app.xaml.cs I initialize the view associated with it:

public thingA View_thingA { get; private set; }
public App()
{
    View_thingA = new thingA();
}

public thingA View_thingA { get; private set; }
public App()
{
    View_thingA = new thingA();
}

then in the MainWindow.xaml.cs, when the respective button is clicked:

private void bt_thingA_Click(object sender, RoutedEventArgs e)
{
    app.View_thingA.ShowDialog();
}

private void bt_thingA_Click(object sender, RoutedEventArgs e)
{
    app.View_thingA.ShowDialog();
}

Jimmacle•2y ago

yeah don't do that you can't reopen the same instance of a window you've already closed, which is exactly what the exception is telling you you need to create a new thingA each time

GipperOP•2y ago

In the button click event? How?

Jimmacle•2y ago

how do you think?

GipperOP•2y ago

private void bt_thingA_Click(object sender, RoutedEventArgs e)
{
    View_thingA = new thingA();
    app.View_thingA.ShowDialog();
}

private void bt_thingA_Click(object sender, RoutedEventArgs e)
{
    View_thingA = new thingA();
    app.View_thingA.ShowDialog();
}

???

Jimmacle•2y ago

you should not be accessing anything from whatever app is

GipperOP•2y ago

aah, ok, fixed thank you any idea why this happened with opening of some windows but not others?

Jimmacle•2y ago

no, but it seems like a bad pattern to be using

GipperOP•2y ago

yeah, it probably is in a perfect world I would like to do it better but oh well

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Windows crashing the program when attempting to reopen windows after having been closed once already