本程序在VB.NET下实现Windows壁纸的自动替换功能，它可以每隔几分钟换一张桌面背景图片。另外，程序还涉及了如何转换一个图片到BMP格式的功能。-The program is implemented in VB.NET the Windows wallpaper automatically replace it every few minutes for a desktop background pictures. In addition, the program also involve