说明：  用DreictX进行抓屏是很简单的，DirectX提供了很优雅的实现。 每个DirectX程序都包含一个被我们称作缓冲的内存区域，其中保存了和该程序有关的显存内容，这在程序中被称作后台缓冲（Back Buffer），有些程序有不止一个的后台缓冲。还有一个缓冲，在默认情况下每个程序都可以访问－前台缓冲。前台缓冲保存了和桌面相关的显存内容，实质上就是屏幕图像。 我们的程序通过访问前台缓冲就可以捕捉到当前屏幕的内容。由DirectX的底层优化机制做保证，我们的抓屏效率是很高的，至少比GDI方式高。
(DreictX carried out with screenshots is very simple, DirectX provides a very elegant implementation. Each contains a DirectX program was what we call the buffer memory region, which is preserved and the procedures related to memory content, which in the procedure, known as the background buffer (Back Buffer), some programs have more than one of the background buffer . There is also a buffer, by default, each program can access- front buffer. Front buffer to preserve the memory and desktop-related content, in essence, is the screen image. Our procedures by visiting the front buffer can capture the current screen content. From the bottom of DirectX optimized mechanism that we are screenshots of the efficiency is very high, at least way more than a high GDI.)