asp.net实现文件下载功能

今天又需要写程序，是网站下载功能。以前曾经有写，是写在一个类别中，http://www.cnblogs.com/insus/articles/1411756.html  也录制过视频，http://www.cnblogs.com/insus/articles/1411761.html 不过还是有网友向Insus.NET索求代码。

今天Insus.NET只好帖出今天写的代码，仅供参考：

<asp:Button ID="ButtonDownload" runat="server" OnClick="ButtonButtonDownload_Click"
                        Text="下载视频" />

xxx.aspx.cs:

 protected void ButtonButtonDownload_Click(object sender, EventArgs e)
    {
        HttpResponse _Response = HttpContext.Current.Response;
        //取数据表
        DataRow objDataRow = objMedia.GetFileByPrimaryKey(id).Rows[0];
        //取得文件目录与文件名。
        string f = objDataRow["Directory"].ToString() + objDataRow["NewFileName"].ToString();
        //取得旧文件名
        string fn = objDataRow["OldFileName"].ToString();

        FileInfo fileInfo = new FileInfo(Server.MapPath (f));
        _Response.Clear();
        _Response.ClearHeaders();
        _Response.Buffer = false;
        _Response.ContentType = "application/octet-stream";
        _Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fn, System.Text.Encoding.UTF8));
        _Response.AppendHeader("Content-Length", fileInfo.Length.ToString());
        _Response.WriteFile(fileInfo.FullName);
        _Response.Flush();
        _Response.End();
    }