//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();
}
}