下载问题

我查了百度 下载的办法是
FileInfo fileInfo = new FileInfo(@"F:\1111\WebApplication1\WebApplication1\Upload\RedGate.Licensing.rar");
            Response.Clear();
            Response.AddHeader("content-disposition", "attachment;filename=" + Server.UrlEncode(fileInfo.Name.ToString()));
            Response.AddHeader("content-length", fileInfo.Length.ToString());
            Response.ContentType = "application/octet-stream";
            Response.ContentEncoding = Encoding.Default;
            Response.WriteFile(@"F:\1111\WebApplication1\WebApplication1\Upload\RedGate.Licensing.rar");
但是我现在是以Ajax请求的方式去下载这个文件 这样写对不对呢
context.Response.ContentType = "text/plain";
            try
            {
                string id = context.Request["id"].ToString();
                Model.File mf = new Model.File();
                BLL.NRBLL bn = new NRBLL();
                Guid guid = new Guid(id);
                mf.Fileid = guid;
                if (bn.FN_SerchResPath(mf) != null)
                {
                    FileInfo fileInfo = new FileInfo(bn.FN_SerchResPath(mf).Tables["t_file"].Rows[0]["FilePath"].ToString());
                    context.Response.Clear();
                    context.Response.AddHeader("content-disposition", "attachment;filename=" + context.Server.UrlEncode(fileInfo.Name.ToString()));
                    context.Response.AddHeader("content-length", fileInfo.Length.ToString());
                    context.Response.ContentType = "application/octet-stream";
                    context.Response.ContentEncoding = Encoding.Default;
                    context.Response.WriteFile(bn.FN_SerchResPath(mf).Tables["t_file"].Rows[0]["FilePath"].ToString());
                    context.Response.Write("0");
                }
                else
                {
                    context.Response.Write("1");
                }
            }
            catch (Exception)
            {                throw;
            }
下载失败了 还是说我这个办法实现不了HTTP的下载