How can I selectively validate a form in WPF?

Question

I'm currently using the validation code listed here in an application. I'd like to selectively validate a page. What I mean by that is this: I have a form that's databound with validation rules attached. I also have a checkbox that, when checked, disables and clears the values of several bound textboxes. Is there a property I can set on these textboxes to tell the validation engine not to include these when validating?

Answer 1

Possibly, you could have triggers that would switch the bindings. Meaning the Setter-s would rebind the property using another bindings with different validation rules.

But that would only(?) work if all those validation rules are in a ControlTemplate or DataTemplate.

Answer 2

Perhaps if you wrote an attached property for your Validator class, and checked for it first thing in your IsValid method.

static class Validator
{
    public static readonly DependencyProperty SkipValidationProperty =
        DependencyProperty.RegisterAttached("SkipValidation", typeof(bool), typeof(Validator),
        new UIPropertyMetadata(false));
    public static bool GetSkipValidation(DependencyObject obj)
    {
        return (bool)obj.GetValue(SkipValidationProperty);
    }
    public static void SetSkipValidation(DependencyObject obj, bool value)
    {
        obj.SetValue(SkipValidationProperty, value);
    }


    public static bool IsValid(DependencyObject parent)
    {
        if (Validator.GetSkipValidation(parent)) return true;
       //Rest of the validation code
    }


}

Then you could do something as simple as:

<StackPanel>
 <TextBox x:Name="txt" local:Validator.SkipValidation="{Binding IsChecked, ElementName=cbx}" />
 <CheckBox x:Name="cbx" >Skip Validate?</CheckBox>        
</StackPanel>