WPF TexBox TwoWay Binding Problem when ValidationRules used

Posted by ignis on Stack Overflow See other posts from Stack Overflow or by ignis
Published on 2010-04-14T06:37:44Z Indexed on 2010/04/14 6:43 UTC
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Filed under:

wpf

|

xaml

|

databinding

I seem to have a problem with TwoWay DataBinding - my application has a window with a bunch of textboxes that allow to edit values of the properties they are bound to. Everything works well except for textboxes that also have a validation rule defined, in which case no text is displayed in the textbox when the window opens (binding back-to-source still works fine for those). If I remove Validation rule, everything's back to normal. I searched for an answer to this for a few hours now, but somehow did not even find anyone else complaining of the same issue. I am completely new to WPF, and I am sure it is just a silly mistake I have somewhere in my code... I will greatly appreciate any feedback...

<TextBox Margin="40,2,20,0" Grid.Column="0" Grid.Row="1" Background="#99FFFFFF" >
        <Binding Path="LastName" Mode="TwoWay" ValidatesOnDataErrors="true" UpdateSourceTrigger="LostFocus" >
                    <Binding.ValidationRules>
                        <validation:StringNameValidationRule />
                    </Binding.ValidationRules>
        </Binding>
</TextBox>

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