C# / .NET messagebox is not modal

Question

Why is a C#/.NET message box not modal?

Accidentally, if the message box goes behind our main UI, then the main UI doesn't respond, until we click OK (on our message box).

Is there a workaround other than creating a custom message box?

Answer 1

You need to assign the MessageBox owner property to the main UI window (look at the 3rd constructor).