I am trying to perform validation in my WPF application using the solution in Detecting WPF Validation Errors.
public static bool IsValid(DependencyObject parent)
{
// Validate all the bindings on the parent
bool valid = true;
LocalValueEnumerator localValues = parent.GetLocalValueEnumerator();
while (localValues.MoveNext())
{
LocalValueEntry entry = localValues.Current;
if (BindingOperations.IsDataBound(parent, entry.Property))
{
Binding binding = BindingOperations.GetBinding(parent, entry.Property);
foreach (ValidationRule rule in binding.ValidationRules)
{
ValidationResult result = rule.Validate(parent.GetValue(entry.Property), null);
if (!result.IsValid)
{
BindingExpression expression = BindingOperations.GetBindingExpression(parent, entry.Property);
System.Windows.Controls.Validation.MarkInvalid(expression, new ValidationError(rule, expression, result.ErrorContent, null));
valid = false;
}
}
}
}
// Validate all the bindings on the children
for (int i = 0; i != VisualTreeHelper.GetChildrenCount(parent); ++i)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (!IsValid(child))
{
valid = false;
}
}
return valid;
}
The problem I am running into is that when I step through the code for a TextBox, I'm not getting the Text property. The only properties I get are "PageHeight", "Instance", and "UndoManagerInstance". Therefore, I can not Validate the rules for the binding on the TextBox.
Does anyone have any idea why I wouldn't be getting the correct properties? Is there another way to force validaton on controls in WPF? I haven't been able to find anyone else who has had this problem.
Update:
The TextBoxes I am trying to validate are within a DataTemplate. I found that if I copy one of the TextBoxes and place it directly in the Window, I am able to get the data. Using Woodstock, I saw that the data source for the TextBoxes in the template is "ParentTemplate", but it's "Local" for the TextBox outside of the template.
So, the question now is, how can I get the DependencyProperties for controls inside a DataTemplate?
