Problem after show a MessageBox in OnValueChanged event

Mar 13, 2012 at 2:19 PM
Edited Mar 13, 2012 at 2:25 PM

In my application, there is a TextBox in the Grid. In this TextBox, the user can input a command such as "CC", the software need to check the text(I used the OnValueChanged event). If it is illegal the software will show a MessageBox, but after that the mouse state is in multi-selection state, it means when I move the mouse, the Grid will keep the selection from the Cell of that TextBox. If I click the Grid again, it will stop the multi-selection state. I think it is a bug and it is sick. Who can help me? Thank you in advance.

Please see the screenshot: