实现了单文档界面的应用，左边为树状图资源管理窗口，中间为主显示区域，下面为输出窗口，右边为逻辑操作窗口，各窗口之间可以自由拖拽(o achieve the application of a single document interface, the left side of the tree for resource management window, the middle of the main display area, the following output window, the