.net中下载文件的方法
一、//TransmitFile实现下载 protected void Button1_Click(object sender, EventArgs e) { /* 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。 代码如下： */ Response.ContentType = "application/x-zip-compressed"; Response.AddHeader("Content-Disposition", "attachment;filename=z.zip"); string filename = Server.MapPath("DownLoad/z.zip"); Response.TransmitFile(filename); }
二、//WriteFile实现下载 protected void Button2_Click(object sender, EventArgs e) { /* using System.IO;
*/ 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(); }
三、 //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(); } }
四、//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(); }
//----------------------------------------------------------
public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody ) {
WebForm.Response.ClearHeaders(); WebForm.Response.Clear(); WebForm.Response.Expires = 0; WebForm.Response.Buffer = true; WebForm.Response.AddHeader("Accept-Language", "zh-tw"); //'文件名称 WebForm.Response.AddHeader("content-disposition", "attachment; filename='"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"'"); WebForm.Response.ContentType = "Application/octet-stream"; //'文件内容 WebForm.Response.Write(FileBody);//----------- WebForm.Response.End(); }
//上面这段代码是下载一个动态产生的文本文件，若这个文件已经存在于服务器端的实体路径，则可以通过下面的函数：
public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath ) { WebForm.Response.ClearHeaders(); WebForm.Response.Clear(); WebForm.Response.Expires = 0; WebForm.Response.Buffer = true; WebForm.Response.AddHeader("Accept-Language", "zh-tw"); //文件名称 WebForm.Response.AddHeader("content-disposition", "attachment; filename='" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"'" ); WebForm.Response.ContentType = "Application/octet-stream"; //文件内容 WebForm.Response.Write(System.IO.File.Rea}dAllBytes(FilePath));//--------- WebForm.Response.End();
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