private void TextBoxItem_Validating(object sender, CancelEventArgs e) { FreeFormDateTimeProvider provider1 = this.Provider as FreeFormDateTimeProvider; if (provider1 != null) { provider1.TryParse(); } else { MaskDateTimeProvider provider2 = this.Provider as MaskDateTimeProvider; if (provider2 == null || this.Value == null) { return; } provider2.ValidateRange(); } }