ContentType 属性 MIME

".asf" = "video/x-ms-asf"
".avi" = "video/avi"
".doc" = "application/msword"
".zip" = "application/zip"
".xls" = "application/vnd.ms-excel"
".gif" = "image/gif"
".jpg"= "image/jpeg"
".wav" = "audio/wav"
".mp3" = "audio/mpeg3"
".mpg" "mpeg" = "video/mpeg"
".rtf" = "application/rtf"
".htm", "html" = "text/html"
".asp" = "text/asp"
 
‘Handle All Other Files
= "application/octet-stream"

原文：http://www.cnblogs.com/xiaoyintao/p/4056332.html