using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ComponentModel;

using System.Windows.Forms;

using System.Drawing;



namespace WindowsFormsApplication2

{

    [DesignerCategory("Default")]

    class TextBoxEx : TextBox

    {

        public TextBoxEx()

        {

            Watermark = "";

        }



        public string Watermark { get; set; }



        private bool ShowsWatermark

        {

            get { return !DesignMode &&  !Focused && Text == ""; }

        }



        private Color WatermarkColor

        {

            get { return SystemColors.GrayText; }

        }



        protected override void WndProc(ref Message m)

        {

            base.WndProc(ref m);



            const int WM_PAINT = 0x000f;

            switch (m.Msg)

            {

                case WM_PAINT:

                    if (ShowsWatermark)

                    {

                        PrintWatermark();

                    }

                    break;

            }

        }



        private void PrintWatermark()

        {

            using (var g = CreateGraphics()) 

            {

                //using (var br = new SolidBrush(BackColor))

                //{

                //    g.FillRectangle(br, this.ClientRectangle);

                //}



                using (var br = new SolidBrush(WatermarkColor))

                {

                    var sf = new StringFormat();

                    g.DrawString(Watermark, Font, br, ClientRectangle, sf);

                }

            }

        }

    }

}