Question

How to prevent to copy & paste any text [using right click and also Ctrl+C and Ctrl+v keys] in masked edit text-box in C#/vb.net?

Answer 1

Inherit from TextBox and override the WndProc method :

private const int WM_CUT = 0x0300;
private const int WM_COPY = 0x0301;
private const int WM_PASTE = 0x0302;

protected override void WndProc(ref Messsage m)
{
    if (m.Msg == WM_CUT || m.Msg == WM_COPY || m.Msg == WM_PASTE)
        return;
    base.WndProc(ref m);
}

It should also prevent copy/paste from the context menu