https://stackoverflow.com/questions/4902565/waterm...
using System.Drawing;
using System.Windows.Forms;
public class ExTextBox : TextBox
{
string hint;
public string Hint
{
get { return hint; }
set { hint = value; this.Invalidate(); }
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == 0xf)
{
if (!this.Focused && string.IsNullOrEmpty(this.Text)
&& !string.IsNullOrEmpty(this.Hint))
{
using (var g = this.CreateGraphics())
{
TextRenderer.DrawText(g, this.Hint, this.Font,
this.ClientRectangle, SystemColors.GrayText , this.BackColor,
TextFormatFlags.Top | TextFormatFlags.Left);
}
}
}
}
}