文件下载

在你的Page_Load中添加这样的代码:

 Page.Response.Clear();
 bool success = ResponseFile(Page.Request, Page.Response, "目的文件名称", @"源文件路径", 1024000);
 if (!success)
     Response.Write("下载文件出错！");
Page.Response.End();

文件下载函数代码为:

public static bool ResponseFile(HttpRequest _Request,HttpResponse _Response,string _fileName,string _fullPath, long _speed)
    {
        try
        {
            FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            BinaryReader br = new BinaryReader(myFile);
            try
            {
                _Response.AddHeader("Accept-Ranges", "bytes");
                _Response.Buffer = false;
                long fileLength = myFile.Length;
                long startBytes = 0;
     
                double pack = 10240; //10K bytes
                //int sleep = 200;   //每秒5次   即5*10K bytes每秒
                int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;
                if (_Request.Headers["Range"] != null)
                {
                    _Response.StatusCode = 206;
                    string[] range = _Request.Headers["Range"].Split(new char[] {'=', '-'});
                    startBytes = Convert.ToInt64(range[1]);
                }
                _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
                if (startBytes != 0)
                {
                    //Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength-1, fileLength));
                }
                _Response.AddHeader("Connection", "Keep-Alive");
                _Response.ContentType = "application/octet-stream";
                _Response.AddHeader("Content-Disposition","attachment;filename=" + HttpUtility.UrlEncode(_fileName,System.Text.Encoding.UTF8) );
             
                br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
                int maxCount = (int) Math.Floor((fileLength - startBytes) / pack) + 1;

                for (int i = 0; i < maxCount; i++)
                {
                    if (_Response.IsClientConnected)
                    {
                        _Response.BinaryWrite(br.ReadBytes(int.Parse(pack.ToString())));
                        Thread.Sleep(sleep);
                    }
                    else
                    {
                        i=maxCount; 
                    }
                }
            }
            catch
            {
             return false;
            }
            finally
            {
                br.Close();

                myFile.Close();
            }
        }
        catch
        {
            return false;
        }
        return true;
    }

这样就实现了文件下载时,不管是什么格式的文件,都能够弹出打开/保存窗口.

防止盗链

protected void Page_Load(object sender, EventArgs e)

{

    /*--------------------------------------------------------------*\

     *                       大文件下载，防盗链                           *

     *                                                              *

     *                       tda7264@163.com                        *

     *                                                              *

     *                   飘遥的BLOG http://xianfen.net              *

    \* -------------------------------------------------------------*/



    if (Request.QueryString["FileName"] == null)

    {

        InvalidRedirect();

    }



    string fileName = Request.QueryString["FileName"];



    if (fileName == string.Empty)

    {

        InvalidRedirect();

    }



    //判断配置文件是否直接下载                  

    string downDirect = ConfigurationManager.AppSettings["Down"].ToLower();



    if (downDirect == "true")

    {

        UpdateHits(fileName);//更新下载次数

        Response.Redirect("Upload/" + fileName);

        return;

    }



    string path = Server.MapPath(Request.ApplicationPath + "/Upload/" + fileName);

    string referrer = string.Empty;



    if (Request.UrlReferrer != null)

    {

        referrer = Request.UrlReferrer.ToString().ToLower();

    }



    string d = ConfigurationManager.AppSettings["Valid"].ToLower();

    string[] domainName = 
ConfigurationManager.AppSettings["Refers"].ToLower().Split(new char[] { ',' });



    // 如果设置为防止盗链，判断访问来源是否合法

    if (d == "false")

    {

        foreach (string s in domainName)

        {

            if (referrer.IndexOf(s.ToLower()) > 0)

            {

                UpdateHits(fileName);//更新下载次数

                ResponseFile(path);

                return;

            }

        }



        InvalidRedirect();

    }

    else

    {

        ResponseFile(path);

    }

}



protected void UpdateHits(string fileName)

{

    //更新文件下载次数的代码

}



protected void InvalidRedirect()

{

    string defaultPage = ConfigurationManager.AppSettings["DefaultRedirect"];



    Response.Redirect(defaultPage, true);

}

配置文件
配置文件中配置下载方式、盗链功能是否开启及盗链默认转向的页面地址：

<appSettings>

  <add key="Down" value="false"/>

  <!--是否直接下载-->

  <add key="Valid" value="false"/>

  <!--是否允许盗链-->

  <add key="Refers" value="localhost,google.cn"/>

  <!--多个允许的访问来源用半角的","分割-->

  <add key="DefaultRedirect" value="Error.htm"/>

  <!--默认转向的页面-->

</appSettings>