Response向客户端发送字节流文件时需要添加的HTTP头

通常我们在做文件下载或文件导出的时候，在把二进制流文件发送到客户端之前都要为HTTP头加上一此属性：

HttpContext.Current.Response.Clear(); 
HttpContext.Current.Response.Buffer = true; 
HttpContext.Current.Response.Charset ="gb2312"; 
HttpContext.Current.Response.AppendHeader("Content-Disposition","attachment;filename="+file_name); 
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312"); 
HttpContext.Current.Response.ContentType = "application/ms-excel"; 
//HttpContext.Current.Response.ContentType = "text/HTML"; 
//image/JPEG;text/HTML;image/GIF;vnd.ms-excel/msword