extension method :
public static class TextBoxWatermarkExtensionMethod { private const uint ECM_FIRST = 0x1500; private const uint EM_SETCUEBANNER = ECM_FIRST + 1; [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)] private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, uint wParam, [MarshalAs(UnmanagedType.LPWStr)] string lParam); public static void SetWatermark(this TextBox textBox, string watermarkText) { SendMessage(textBox.Handle, EM_SETCUEBANNER, 0, watermarkText); } }
how to use it example on form constructor :
public TIDFrmIDSKirimUang() { InitializeComponent(); TextBoxWatermarkExtensionMethod.SetWatermark(txtTNoHP,"0815xxxxxxx"); TextBoxWatermarkExtensionMethod.SetWatermark(txtNoHP,"0815xxxxxxx"); }
reference :
http://vidmar.net/weblog/archive/2008/11/05/watermarked-textbox-in-windows-forms-on-.net.aspx
