Transparent border in WPF programmatically
This is because you can't just cast a Color to be a Brush. use the Transparent brush instead
border.Background = Brushes.Transparent;
Use a SolidColorBrush:
border.Background = new SolidColorBrush(Colors.Transparent);The VisualBrush has a different purpose. See an overview of the main types of WPF brushes here:
You can also create a SolidColorBrush with transparent color:This will create a fully transparent color
border.Background = new SolidColorBrush(Color.FromArgb(0, 0, 0, 0));but you can also make semitransparent color by changing alpha (this will look like 50% transparent red:
border.Background = new SolidColorBrush(Color.FromArgb(128, 255, 0, 0));