屏幕截图，并存储成bmp/jpg/gif/png等多种文件格式 包括：拷贝屏幕、gdiplus图形文件转换、位图创建不规则窗体的内容-Screenshots, and stored into a bmp/jpg/gif/png and other file formats include: copies of the screen, gdiplus graphics file conversion, bitmap to create the content of irregular form