Question

I have a control which i’m putting in dialog as a content. Due to relization of this dialog i have to create it every time when i need it(Show/Hide won’t do the trick). I want my control to remember field content beetween calls. While i can apply viewmodel to achieve this i prefer just keep control as a field and assing it as content of dialog every time i need it. But i run into following error:

“Specified element is already the logical child of another element. Disconnect it first.”

I tried to assing null to dialog window’s content before closing it, but it doesn’t solve the problem. Is there anything i can do?

Answer 1

Setting window.Content = null works fine for me. Following is the code I used:

public partial class MainWindow : Window
{
    TextBlock textBlock = new TextBlock();
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        TestWindow testWindow = new TestWindow();
        testWindow.Content = textBlock;
        testWindow.Closing += HandleTestWindowClosing;
        testWindow.Show();
    }

    void HandleTestWindowClosing(object sender, System.ComponentModel.CancelEventArgs e)
    {
        var testWindow = sender as TestWindow;
        if(testWindow!=null)
        {
            testWindow.Content = null;
            testWindow.Closing -= HandleTestWindowClosing;
        }
    }
}