private void OnLeftSizeToolPositionChanged(object sender, DragObjectEventArgs e)
{
WindowApi.RECT rect = new WindowApi.RECT();
WindowApi.GetWindowRect(this.handle, ref rect);
rect.left -= (int)e.Delta.X;
WindowApi.MoveWindow(this.handle, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, false);
}