//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
String s = fileName;
byte[] buffer = Encoding.UTF8.GetBytes(s);
String Text = Encoding.GetEncoding("GBK ").GetString(buffer);//HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)
Response.AddHeader("Content-Disposition", "attachment; filename=" + Text);
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}