Add null check in UpdateButtonState to prevent potential NullReferenceException

Copilot · ayushjai19 · Copilot · commit cac0ba8fc715 · 2025-12-18T10:28:00.000Z
Co-authored-by: ayushjai19 &lt;244442986+ayushjai19@users.noreply.github.com&gt;
diff --git a/WinUIGallery/Samples/ControlPages/Fundamentals/Controls/TemperatureConverterControl.xaml.cs b/WinUIGallery/Samples/ControlPages/Fundamentals/Controls/TemperatureConverterControl.xaml.cs
@@ -44,7 +44,7 @@ private void InputTextBox_TextChanged(object sender, TextChangedEventArgs e)
 
     private void UpdateButtonState()
     {
-        IsConvertButtonEnabled = !string.IsNullOrWhiteSpace(InputTextBox.Text);
+        IsConvertButtonEnabled = InputTextBox != null && !string.IsNullOrWhiteSpace(InputTextBox.Text);
     }
 
     private void Button_Click(object sender, RoutedEventArgs e)

Original file line number	Diff line number	Diff line change
`@@ -44,7 +44,7 @@ private void InputTextBox_TextChanged(object sender, TextChangedEventArgs e)`
`44`	`44`
`45`	`45`	`private void UpdateButtonState()`
`46`	`46`	`{`
`47`		`- IsConvertButtonEnabled = !string.IsNullOrWhiteSpace(InputTextBox.Text);`
	`47`	`+ IsConvertButtonEnabled = InputTextBox != null && !string.IsNullOrWhiteSpace(InputTextBox.Text);`
`48`	`48`	`}`
`49`	`49`
`50`	`50`	`private void Button_Click(object sender, RoutedEventArgs e)`