ASP.NET C# 文件下载

1.文件下载到客户端

//WriteFile实现下载

protected void Download_Click(object sender, EventArgs e)
{
　　string fileName = "20151223Test.doc";//客户端保存的文件名
　　//string filePath = Server.MapPath("DownLoad/aaa.txt");//路径
　　string filePath = Server.MapPath(@"files est.doc");//路径

　　FileInfo fileInfo = new FileInfo(filePath);
　　Response.Clear();
　　Response.ClearContent();
　　Response.ClearHeaders();
　　Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
　　Response.AddHeader("Content-Length", fileInfo.Length.ToString());
　　Response.AddHeader("Content-Transfer-Encoding", "binary");
　　Response.ContentType = "application/octet-stream";
　　//Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
　　Response.ContentEncoding = System.Text.Encoding.UTF8;
　　Response.WriteFile(fileInfo.FullName);
　　Response.Flush();
　　Response.End();
}

//TransmitFile实现下载
protected void DownLoadTF_Click(object sender, EventArgs e)
{

　　Response.ContentType = "application/x-zip-compressed";
　　Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");
　　string filename = Server.MapPath(@"filesDownloadsText.zip");
　　Response.TransmitFile(filename);
　　//Response.TransmitFile 需要 ：Microsoft .NET Framework 1.1 Service Pack 1 支持！！
}

//流方式下载
protected void DownLoadFL_Click(object sender, EventArgs e)
{
　　string fileName = "20151223aaa.doc";//客户端保存的文件名
　　//string filePath = Server.MapPath("DownLoad/aaa.txt");//路径
　　string filePath = Server.MapPath(@"files租户装修手册-印象城.doc");//路径

　　//以字符流的形式下载文件
　　using (FileStream fs = new FileStream(filePath, FileMode.Open))
　　{
　　　　byte[] bytes = new byte[(int)fs.Length];
　　　　fs.Read(bytes, 0, bytes.Length);

　　　　Response.ContentType = "application/octet-stream";
　　　　//通知浏览器下载文件而不是打开
　　　　Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
　　　　Response.BinaryWrite(bytes);
　　　　Response.Flush();
　　　　Response.End();
　　}
}

//流方式下载 2
protected void DownLoadFL2_Click(object sender, EventArgs e)
{
　　string fileName = "20151223aaa.doc";//客户端保存的文件名
　　//string filePath = Server.MapPath("DownLoad/aaa.txt");//路径
　　string filePath = Server.MapPath(@"files租户装修手册-印象城.doc");//路径

　　//以字符流的形式下载文件
　　using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
　　{
　　　　byte[] bytes = new byte[(int)fs.Length];
　　　　using (BinaryWriter bw = new BinaryWriter(fs))
　　　　{
　　　　　　bw.Write(bytes);
　　　　　　bw.Close();
　　　　　　Response.ContentType = "application/octet-stream";
　　　　　　//通知浏览器下载文件而不是打开
　　　　　　Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
　　　　　　Response.BinaryWrite(bytes);
　　　　　　Response.Flush();
　　　　　　Response.End();
　　　　}
　　}
}

 //http请求常用下载方式；

//通过webClient方式

WebClient client = new WebClient();
string url="http://down6.3987.com:801/2010/office_3987.com.zip";
Stream strm = client.OpenRead("http://down6.3987.com:801/2010/office_3987.com.zip");
string filename=url.Substring(url.LastIndexOf('/')+1);
int count = 0;
byte[] buffer = new byte[4096];
FileStream fs = new FileStream(Application.StartupPath+"//"+filename, FileMode.Create);
while ((count = strm.Read(buffer, 0, buffer.Length)) > 0) {

fs.Write(buffer, 0, count);

}
fs.Close();
strm.Close();
strm.Dispose();
fs.Dispose();

//通过原生态HttpWebrequest方式

string url = "http://down6.3987.com:801/2010/office_3987.com.zip";

string filename = url.Substring(url.LastIndexOf('/') + 1);
//用webClient方式创建http请求
HttpWebRequest req =(HttpWebRequest)HttpWebRequest.Create(url) ; //创建链接

//获取服务其数据
HttpWebResponse res = (HttpWebResponse)req.GetResponse();

Stream mystream = res.GetResponseStream();

//开始文件操作
FileStream fs = new FileStream(AppDomain.CurrentDomain.BaseDirectory+"//"+filename, FileMode.Create, FileAccess.Write, FileShare.None);

byte[] buffer=new byte[1024];
int count=0;
while((count=mystream.Read(buffer,0,1024))>0)
{
fs.Write(buffer, 0, count);
}

fs.Close();
mystream.Close();
fs.Dispose();

参考：C#中http请求下载的常用方式demo