/// <summary>
        /// DesignRectangle控件鼠标左键按下
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void dr_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            DesignRectangle item = sender as DesignRectangle;

            mouseVerticalPosition   = e.GetPosition(cvsPanle).Y;
            mouseHorizontalPosition = e.GetPosition(cvsPanle).X;
            isMouseCaptured         = true;
            isMoveByDesignRectangle = false;
            item.CaptureMouse();
            e.Handled            = true;
            line_Top.Visibility  = System.Windows.Visibility.Visible;
            line_Left.Visibility = System.Windows.Visibility.Visible;
        }