A ComboBox.SelectedItemProperty is bound TowWay to a DependencyProperty in The Control.
In the ControlTemplate :
<ComboBox IsEditable="True">
<ComboBox.SelectedItem>
<Binding RelativeSource="{RelativeSource TemplatedParent}"
Path="SomeDP" Mode="TwoWay" NotifyOnValidationError="True">
<Binding.ValidationRules>
<vld:DeleteAfterInitValidationRule ValidatesOnTargetUpdated="True" />
</Binding.ValidationRules>
</Binding>
</ComboBox.SelectedItem>
</ComboBox>
When the ValidationRule returns false
return ValidationResult(false,msg);
The Dependency Property bound to selected item is not updated.
Is there a way to force the binding to update the source ?
*Please if any one is going to raise a discussion here about
BindingExpression.UpdateSource() , please supply a working example, and not just blurt it out because it sounds like the solution , i do not intend to use Explicit mode on my Binding.
Further more i can easily code my way around this but a good .net programmer should thrive to write less code and use the built in mechanisms supplied by the .net framework ,
And that is the soul purpose of this question , is there a built in way of updating the source while notifying of a DataError ?