public void TextImport(string path, string name)
        {
            FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
            StreamReader sr = new StreamReader(fs.Name, System.Text.Encoding.GetEncoding("GB2312"), true);
            sr.BaseStream.Seek(0, SeekOrigin.Begin);
            Regex reg = new Regex(@"1[3|5|8]\d{9}");
            while (!sr.EndOfStream)
            {
                if (!reg.IsMatch(sr.ReadLine()))//插入电话号码
                   ..........................
            }
            sr.Close();//释放资源
            fs.Close();//关闭流
            Response.Write("<script>alert('导入成功!')</script>");
        }

------解决方案--------------------

C# code

//获得readTxt文件下所有 .txt文件 循环读取
string[] fileList = Directory.GetFiles(@"d:\readTxt", "*.txt");
            foreach (string strPath in fileList)
            {
                using (StreamReader read = new StreamReader(strPath))
                {
                    string str = read.ReadLine();//逐行读取 插入数据库
                }
            }