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。 -Create a panel containing a box, the user can grab the mouse box, but no matter how hard the user, always moving boxes moving in the opposite direction with the mouse movement, and t