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

测试代码如下：

1 　　     //读取txt文件中总行数的方法 2         public static int requestMethod(String _fileName) 3         { 4             Stopwatch sw = new Stopwatch(); 5             var path = _fileName; 6             int lines = 0; 7  8             //按行读取 9             sw.Restart();10             using (var sr = new StreamReader(path))11             {12                 var ls = "";13                 while ((ls = sr.ReadLine()) != null)14                 {15                     lines++;16                 }17             }18             sw.Stop();19             return lines;20         }