'WIN32下
Dim a As New System.Drawing.Bitmap("C:\Documents and Settings\xuwang\桌面\image2\" & DateTime.Now.ToShortDateString & ".jpg")
PictureBox1.BackgroundImage = a
'WEB
Image1.ImageUrl="C:\Documents and Settings\xuwang\桌面\image2\" + DateTime.Now.ToShortDateString() + ".jpg"