private void T2_MouseMove(object sender, MouseEventArgs e)
{
var ctrl = sender as TextBox;
var x = e.X;
var y = e.Y;
//dm.GetCursorPos(out x, out y);
if (hwnd > 0)
{
var r = dm.GetWindowRect(hwnd);
x -= r.X;
y -= r.Y;
}
ctrl.Text = x + "," + y;
}