In Prism application I want to using validation.And I have implement the INotifyDataError interface in my ViewModel ,but I found that the validate solution don't be fired when the control is loaded first time.
Then I found the same Question like 'wpf Validation Binding not fired on First Load'
I Found a solution to solve the problem WPF don't fired the validation when first load the datacontext is that:
<TextBox Grid.ColumnSpan="2" Grid.Row="1" x:Name="textBoxFolder" Margin="2,4">
<TextBox.Text>
<Binding Path="this.MovieFolder" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<!-- Validation rule set to run when binding target is updated. -->
<Rules:MandatoryInputRule ValidatesOnTargetUpdated="True" />
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
as you see,ValidatesOnTargetUpdated="True"
is the key point ,this property will make WPF fired the validation when the datacontext load first time.
But I think that's a ugly solution. I need to add a Binding.ValidationRules
for every control I want to validate.
Is there a good way to solve the problem.