CODEWITHSUNDEEP
c#.netwpf
Bender
Bender

Reputation: 523

System.InvalidOperationException: Can not set Visibility

I created a window that can be closed only when you click outside of it. The code works very well here:

 protected override void OnDeactivated(EventArgs e)
 {
     try
     {
         base.OnDeactivated(e);
         Close();
     }
     catch (Exception ex) { Console.WriteLine(ex.ToString()); }
 }

The only problem comes when the window is closed, for example, with alt + f4, in particular, takes this exception:

You can not set Visibility to Visible or call Show, ShowDialog, Close WindowInteropHelper.EnsureHandle or while you are on the closure of the Window.

How can I make sure to avoid it? Actually I've managed the exception with Try/Catch..

Upvotes: 3

Views: 1111

Answers (1)

andreask
andreask

Reputation: 4298

Before the window's Deactivated event is raised, the Closing event occurs (but, obviously, only if the window is closed on purpose by the user, e.g. by pressing Alt+F4). This means you can set a flag in the window's Closing event handler indicating that the window is currently being closed, meaning that the Close() method needs not be called in the Deactivated event handler:

    private bool _isClosing;

    protected override void OnClosing(CancelEventArgs e)
    {
        base.OnClosing(e);
        _isClosing = true;
    }

    protected override void OnDeactivated(EventArgs e)
    {
        base.OnDeactivated(e);
        if (!_isClosing)
            Close();
    }

Upvotes: 3

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