Why is DialogResult True when I set it to False?

Question

I have a ChildWindow displayed. I have a Button with a Click event. The Click even sets DialogResult = False. I have a Closing event listener on the ChildWindow.
When the Closing event is entered, the sender is the ChildWindow and the Sender's DialogResult = TRUE!???
DialogResult was already False, when the Click event happened.
How the heck did it get to be TRUE?
And nothing else sets DialogResult in my code as far as I could find.

Answer 1

I put together a very simple MainPage:
<Grid x:Name="LayoutRoot" Background="White">
<Button Click="Button_Click">Show Child</Button>
</Grid>
and
public MainPage()
InitializeComponent();
private void Button_Click(object sender, RoutedEventArgs e)
ChildWindow1 cw = new ChildWindow1();
cw.Closed += new EventHandler(cw_Closed);
cw.Show();
void cw_Closed(object sender, EventArgs e)
ChildWindow1 cw = (ChildWindow1)sender;
if (cw.DialogResult == true )
ChildWindow1 is a regular child window
It's generated with this code:
public partial class ChildWindow1 : ChildWindow
public ChildWindow1()
InitializeComponent();
private void OKButton_Click(object sender, RoutedEventArgs e)
this.DialogResult = true;
private void CancelButton_Click(object sender, RoutedEventArgs e)
this.DialogResult = false;
I put a breakpoint in the line
if (cw.DialogResult == true )
When I click OK I get true returned.
When I click cancel I get false returned.
Hope that helps.
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