Question

How do I change the background color of a XAML textbox depending on value at runtime? These color values can be customized by the end user. Seems I can’t just set the “Background” property.

    <TextBox Name="nameInput" Width="300" HorizontalAlignment="Left" />

How would the code behind look to accomplish this? This doesn’t work:

Private Sub NameInput_TextChanged(sender As Object, e As TextChangedEventArgs) Handles nameInput.TextChanged

    Select Case nameInput.Text
        Case "x"
            nameInput.Background = "Red"
        Case "y"
            nameInput.Background = "Green"
    End Select
End Sub

Answer 1

you need to assign SolidColorBrush instead of just Color.

Private Sub NameInput_TextChanged(sender As Object, e As TextChangedEventArgs) Handles nameInput.TextChanged

Select Case nameInput.Text
    Case "x"
        nameInput.Background = new SolidColorBrush(Windows.UI.Colors.Red);
    Case "y"
        nameInput.Background = new SolidColorBrush(Windows.UI.Colors.Green);
End Select
End Sub