实现窗口的层叠平铺，包括横向平铺、纵向平铺、排列图标等操作，还包括复制、粘贴等操作。整个程序类似一个Windows的记事本一样。-Cascade realization of a window tiling, including horizontal tiling, vertical tiling, Arrange Icons and other operations, including copy, paste and other operations. The entire process