DataGridTextColumn doesn't allow to enter "double" value

Question

I have property double? MyDouble { get .. set ... }. I've binded it in DataGridTextColumn:

<DataGridTextColumn Binding="{Binding MyDouble}" />

It works fine unless I add UpdateSourceTrigger=PropertyChanged.

<DataGridTextColumn Binding="{Binding MyDouble, 
                              UpdateSourceTrigger=PropertyChanged}" />

In this case I can't enter "." and add "double" value. How can I avoid this behavior?

Answer 1

Uninstall .NET 4.5 Beta. I've posted this bug to Microsoft support.