c#文件下载示例的4种方法

原文链接：http://www.jb51.net/article/57068.htm

C#实现HTTP下载文件的方法

/// <summary>/// Http下载文件/// </summary>public static string HttpDownloadFile(string url, string path){    // 设置参数    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;    //发送请求并获取相应回应数据    HttpWebResponse response = request.GetResponse() as HttpWebResponse;    //直到request.GetResponse()程序才开始向目标网页发送Post请求    Stream responseStream = response.GetResponseStream();    //创建本地文件写入流    Stream stream = new FileStream(path, FileMode.Create);    byte[] bArr = new byte[1024];    int size = responseStream.Read(bArr, 0, (int)bArr.Length);    while (size > 0)    {        stream.Write(bArr, 0, size);        size = responseStream.Read(bArr, 0, (int)bArr.Length);    }    stream.Close();    responseStream.Close();    return path;}

原文链接：http://www.jb51.net/article/47822.htm

1、TransmitFile实现下载

protected void Button1_Click(object sender, EventArgs e){    Response.ContentType = "application/x-zip-compressed";    Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");    string filename = Server.MapPath("DownLoad/z.zip");    Response.TransmitFile(filename);}

2、WriteFile实现下载

//WriteFile实现下载protected void Button2_Click(object sender, EventArgs e){    string fileName = "asd.txt";//客户端保存的文件名    string filePath = Server.MapPath("DownLoad/aaa.txt");//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.WriteFile(fileInfo.FullName);    Response.Flush();    Response.End();}

3、WriteFile分块下载

//WriteFile分块下载protected void Button3_Click(object sender, EventArgs e){    string fileName = "aaa.txt";//客户端保存的文件名    string filePath = Server.MapPath("DownLoad/aaa.txt");//路径    System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);    if (fileInfo.Exists == true)    {        const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力        byte[] buffer = new byte[ChunkSize];        Response.Clear();        System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);        long dataLengthToRead = iStream.Length;//获取下载的文件总大小        Response.ContentType = "application/octet-stream";        Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));        while (dataLengthToRead > 0 && Response.IsClientConnected)        {            int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小            Response.OutputStream.Write(buffer, 0, lengthRead);            Response.Flush();            dataLengthToRead = dataLengthToRead - lengthRead;        }        Response.Close();    }}

4、流方式下载

//流方式下载protected void Button4_Click(object sender, EventArgs e){    string fileName = "aaa.txt";//客户端保存的文件名    string filePath = Server.MapPath("DownLoad/aaa.txt");//路径                                                         //以字符流的形式下载文件    FileStream fs = new FileStream(filePath, FileMode.Open);    byte[] bytes = new byte[(int)fs.Length];    fs.Read(bytes, 0, bytes.Length);    fs.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();}