WPF Window Closing does not work after Cancel : <p>I have an issue that I can't seem to resolve via Google (likely because I'm not searching the right criteria). I have a Closing Event that checks if a button is enabled and pops a messagebox  with a result (Yes/No). If the user says NO, I get the desired results in the app; however, the X in the top right corner stops working. How to I "reinstate" the close button ("X" in the top right hand corner) so it works again if pressed (and also evaluates the logic again). </p>

<p>I tried this: <a href="https://stackoverflow.com/questions/3001525/how-to-override-default-window-close-operation">Stackoverflow Question</a></p>

<p>i don't think I want to play with Visibility of the window. The window doesnt go anywhere. They have dirty data and they need to fix it or have it auto saved. </p>

<p>What I have in the application is:</p>

<pre><code>        private void DXWindow_Closing(object sender, CancelEventArgs e)
    {

        if (BtnPatSave.IsEnabled == false) return;
        if (MessageBox.Show(Properties.Resources.PatAcctMsgBox3, Properties.Resources.PatAcctMsgBox1,
                MessageBoxButton.YesNo,
                MessageBoxImage.Warning) == MessageBoxResult.No)
        {
            e.Cancel = true;
        }
        else
        {
            var patId = TbPatId.Text;
            var usl = new UnSetLockValue();
            usl.UnSetVal(patId);
            Log.Info("Patient Account is now unlocked by user: " + Environment.UserName);
        }
    }
</code></pre>
