分割窗口QSplitter类在应用程序中经常用到，它可以灵活分布窗口的布局，经常用在类似文件资源管理器的窗口设计中。此程序实现了一个非常简单的分割窗口功能，整个对话框由三个窗口组成，各窗口之间的大小可以随意拖动改变。-Split the window QSplitter classes frequently used in the application, it can be flexible distribution of the layout of the window, often used in similar to the File Explorer window design. This program a very simple split-window function, the entire dialog is composed by three windows, the size of each window can drag to change.