WPF ValidationRule Validate when the control is loaded
- by PaN1C_Showt1Me
Hi !
I have a control with this validation
<MyPicker.SelectedItem>
<Binding Path="Person.Value" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged" NotifyOnValidationError="True">
<Binding.ValidationRules>
<rules:MyValidationRule ValidationType="notnull"/>
</Binding.ValidationRules>
</Binding>
</MyPicker.SelectedItem>
This is the Validation Class:
class MyValidationRule : ValidationRule
{
private string _validationType;
public string ValidationType
{
get { return _validationType; }
set { _validationType = value; }
}
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
ValidationResult trueResult = new ValidationResult(true, null);
switch (_validationType.ToLower())
{
case "notnull": return value == null ? new ValidationResult(false, "EMPTY FIELD") : trueResult;
default: return trueResult;
}
}
}
Question: When the property is changed, then the Validate( ) method is called which is correct.
But to call this method at the very beginning when the MyControl is created? I need to prove immediate after initialize if the there's a null value in the control (and display a validation error)
