C#下载文件(TransmitFile/WriteFile/流方式)实例介绍

usingSystem;
usingSystem.Data;
usingSystem.Configuration;
usingSystem.Web;
usingSystem.Web.Security;
usingSystem.Web.UI;
usingSystem.Web.UI.WebControls;
usingSystem.Web.UI.WebControls.WebParts;
usingSystem.Web.UI.HtmlControls;
usingSystem.IO;
publicpartialclass_Default:System.Web.UI.Page
{
protectedvoidPage_Load(objectsender,EventArgse)
{
}
//TransmitFile实现下载
protectedvoidButton1_Click(objectsender,EventArgse)
{
Response.ContentType="application/x-zip-compressed";
Response.AddHeader("Content-Disposition","attachment;filename=z.zip");
stringfilename=Server.MapPath("DownLoad/z.zip");
Response.TransmitFile(filename);
}
//WriteFile实现下载
protectedvoidButton2_Click(objectsender,EventArgse)
{
stringfileName="asd.txt";//客户端保存的文件名
stringfilePath=Server.MapPath("DownLoad/aaa.txt");//路径
FileInfofileInfo=newFileInfo(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
protectedvoidButton3_Click(objectsender,EventArgse)
{
stringfileName="aaa.txt";//客户端保存的文件名
stringfilePath=Server.MapPath("DownLoad/aaa.txt");//路径
System.IO.FileInfofileInfo=newSystem.IO.FileInfo(filePath);
if(fileInfo.Exists==true)
{
constlongChunkSize=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=newbyte[ChunkSize];
Response.Clear();
System.IO.FileStreamiStream=System.IO.File.OpenRead(filePath);
longdataLengthToRead=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)
{
intlengthRead=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
protectedvoidButton4_Click(objectsender,EventArgse)
{
stringfileName="aaa.txt";//客户端保存的文件名
stringfilePath=Server.MapPath("DownLoad/aaa.txt");//路径
//以字符流的形式下载文件
FileStreamfs=newFileStream(filePath,FileMode.Open);
byte[]bytes=newbyte[(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();
}
}