C# 文件下载四方法
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using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; using System.IO; public partial class _Default : System.Web.UI.Page { protected void Page_Load( object sender, EventArgs e) { } //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); } //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(); } //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(); } } //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(); } } |