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>