C#下载的几种方法

今天总结了下下载的几种方法。把代码贴出来了，方便自己以后查找。 下载的4种方式： 1、TransmitFile实现下载 [code lang="csharp"] private void DownLoadByTransmitFile(string filePath,string filename) { /* * 微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite * 下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。 */ Response.ContentType = "application/x-zip-compressed"; Response.AddHeader("Content-Disposition",string.Format("attachment;filename={0}",filename)); Response.TransmitFile(filePath); } [/code] 2、WriteFile实现下载 [code lang="csharp"] private void DownLoadByWriteFile(string filePath, string fileName) { 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(); } [/code] 3、WriteFile分块下载 [code lang="csharp"] private void DownLoadByWriteFilePart(string filePath, string fileName) { FileInfo fileInfo = new 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(); FileStream iStream = File.OpenRead(filePath); long dataLengthToRead = iStream.Length;//获取下载文件总大小 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(); } } [/code] 4、字符流形式下载 [code lang="csharp"] private void DownLoadByIO(string filePath, string fileName) { //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(); } [/code] 下载的方法： [code lang="csharp"] //下载 protected void Button1_Click(object sender, EventArgs e) { string filename="11.txt"; string filePath = Server.MapPath(filename); DownLoadByTransmitFile(filePath, filename); } [/code]