asp.net 下载功能出错？？？~~

Question

 System.IO.FileInfo file = new System.IO.FileInfo(filepath);
           Response.Clear();
           Response.AddHeader("Content-Disposition", "attachment;filename=" + file.Name);
           Response.AddHeader("Content-Length", file.Length.ToString());
           Response.ContentType = "application/octet-stream";
           Response.WriteFile(file.FullName);
           Response.End();           Response.Flush();
           Response.Clear();执行到Response.End(); 弹出对话框说：无法复制文件：无法读源文件或磁盘。
调试filepath路径是正确

Answer 1

去掉这句呢？
          Response.End();