由于项目需要，需要制作一个多文档操作的界面，所以就有了这个结果。利用窗口融合，把窗口融合pagecontrol中，以实现多文档的界面-Since the project needs, need to make a multi-document operation interface, so there will be the result. Using windows integration, integration pagecontrol the window in order to achieve multi-document interface