fileupload直接获得

        if (fu.PostedFile.InputStream.Length < 1)
        {
            Comm.MessageBox.Show("请选择文件");
        }
        string FileName = fu.FileName;//上传文件文件名
        string FilePath = fu.PostedFile.FileName;//上传文件完整路径+文件名
        if (FileName.ToLower().IndexOf(".txt") == -1)
        {
            Comm.MessageBox.Show("请选择要求的类型的文件");
        }
        int FileLen = fu.PostedFile.ContentLength;//获取上传文件的大小
        byte[] input = new byte[FileLen];
        System.IO.Stream UpLoadStream = fu.PostedFile.InputStream;
        UpLoadStream.Read(input, 0, FileLen);
        UpLoadStream.Position = 0;
        System.IO.StreamReader sr = new System.IO.StreamReader(UpLoadStream, System.Text.Encoding.Default);
        string aa = sr.ReadToEnd();
        sr.Close();
        UpLoadStream.Close();
        UpLoadStream = null;
        sr = null;