private void DelTool(NativeMethods.TOOLINFO toolInfo)
 {
     IntPtr lresult = NativeMethods.SendMessage(Handle, NativeMethods.TTM_DELTOOL, IntPtr.Zero, ref toolInfo);
 }
 private bool AddTool(NativeMethods.TOOLINFO toolInfo)
 {
     IntPtr retVal = NativeMethods.SendMessage(Handle, NativeMethods.TTM_ADDTOOL, IntPtr.Zero, ref toolInfo);
     return (retVal != IntPtr.Zero);
 }