本代码制作抓不住的方块的实例。程序执行后，创建一个含有方块的面板，用户可以通过鼠标抓取方块，但是，无论用户怎样努力，方块总是朝着与鼠标运动相反的方向运动，这就是抓不住的方块。 -Not catch the code produced examples of the box. Procedures implemented, to create a box containing the panel, the user can mouse crawling through the box, but regardless of how the efforts of users, the box is always moving with the mouse movement in the opposite direction movement, and this is the side grip block.