[C#]统计文本文件txt中的行数(快速读取)

快速统计文本文件中的行数( StreamReader.ReadLine() ):

测试代码如下：

　　     //读取txt文件中总行数的方法
        public static int requestMethod(String _fileName)
        {
            Stopwatch sw = new Stopwatch();
            var path = _fileName;
            int lines = 0;

            //按行读取
            sw.Restart();
            using (var sr = new StreamReader(path))
            {
                var ls = "";
                while ((ls = sr.ReadLine()) != null)
                {
                    lines++;
                }
            }
            sw.Stop();
            return lines;
        }