TextBox with a Transparent Background [duplicate]

Answer 1

Put this in the constructor:

SetStyle(ControlStyles.SupportsTransparentBackColor, true);

The class need to enable the transparent style. (For some reason it isn't supported by default).

public class MyControl : System.Windows.Forms.UserControl
{
        public MyControl ()
        {
            // Create visual controls
            InitializeComponent();
            SetStyle(ControlStyles.SupportsTransparentBackColor, true);
        }
}

Or if it's not a custom control:

mycontrolObject.SetStyle(ControlStyles.SupportsTransparentBackColor, true);

More about Control.SetStyle Method

Other Control Styles