private static void OnTargetPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Label label = d as Label;
if (label != null)
{
label.LoadMetadata(false);
label._errors.Clear();
FrameworkElement oldElement = e.OldValue as FrameworkElement;
FrameworkElement newElement = e.NewValue as FrameworkElement;
EventHandler <ValidationErrorEventArgs> bindingHandler = new EventHandler <ValidationErrorEventArgs>(label.Target_BindingValidationError);
if (oldElement != null)
{
oldElement.BindingValidationError -= bindingHandler;
}
if (newElement != null)
{
newElement.BindingValidationError += bindingHandler;
ReadOnlyObservableCollection <ValidationError> newErrors = Validation.GetErrors(newElement);
if (newErrors.Count > 0)
{
// Only the first error is used by binding
label._errors.Add(newErrors[0]);
}
}
label.ParseTargetValidState();
}
}
private static void OnPropertyPathPropertyChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e)
{
Label label = depObj as Label;
if (label != null && label.Initialized)
{
label.LoadMetadata(false);
// Changing the PropertyPath sometimes requires an update for the validation state, since it might be stale.
label.ParseTargetValidState();
}
}
private static void OnDataContextPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Label label = d as Label;
if (label != null)
{
if (e.OldValue == null || e.NewValue == null || e.OldValue.GetType() != e.NewValue.GetType())
{
// Refresh the metadata, but only if the DataContext's type has changed (or if either is null)
label.LoadMetadata(false);
}
}
}