private ValidationResultsCollection Validate()
{
ValidationResultsCollection result = DoValidation();
if (result == null)
{
Throw.InvalidOperationException(Res.ComponentModelDoValidationNull);
}
bool newIsValid = !result.HasErrors;
bool raiseIsValidChanged = newIsValid != lastIsValid;
isValid = lastIsValid = newIsValid;
ValidationResultsCollection lastResult = cachedValidationResults;
bool raiseValidationResultsChanged = lastResult?.SequenceEqual(result) != true;
cachedValidationResults = result.ToReadOnly();
if (raiseIsValidChanged)
{
OnPropertyChanged(new PropertyChangedExtendedEventArgs(!newIsValid, newIsValid, nameof(IsValid)));
}
if (raiseValidationResultsChanged)
{
OnPropertyChanged(new PropertyChangedExtendedEventArgs(lastResult, result, nameof(ValidationResults)));
}
return(result);
}
/// <inheritdoc />
protected internal override void OnPropertyChanged(PropertyChangedExtendedEventArgs e)
{
if (e == null)
{
Throw.ArgumentNullException(Argument.e);
}
// Invalidating cached validation results if an affected property has changed.
if (isValid != null && AffectsModifiedState(e.PropertyName))
{
isValid = null;
cachedValidationResults = null;
}
base.OnPropertyChanged(e);
}