C# ASPX.NET 文件（图片）下载

最好使用aspx页面写：

 protected void Page_Load(object sender,EventArgs e)
 {
      if(!IsPostBack)
     {
         System.Io.FileStream myFileStream = new System.Io.FileStream(Server.MapPath("",System.Io.FileMode.Open));
         long FileSize;
         FileSize = myFileStream.Length;
 　　　　 byte[] Buffer = new byte[(int)FileSize];
         myFileStream.Read(Buffer,,(int)myFileStream.Length);
         myFileStream.Close();

         Response.Clear();
         Response.ClearHeaders();
         Response.Content();
         Response.ContentType = "image/png";
         Response.AddHeader("content-disposition","attachment:filename="+"文件名.png",System.Text.Encoding.UTF8)
         Response.BinaryWrite(Buffer );
     }
 }