解决MVC模式文件下载附件中文名称乱码

解决如下：

进行url编码：Server.UrlPathEncode(file.AttachmentName)

 return File(file.TempWorkPath, CommonTools.GetContentType(Path.GetExtension(file.TempWorkPath).Replace(".", "")), Server.UrlPathEncode(file.AttachmentName));