string[] line=File.ReadAllLines("e:\a.txt");
            int lines = line.Length;

------解决方案--------------------
StreamReader txtReader = new StreamReader(Application.StartupPath + "\\aa.txt.txt");  
string[] reader = new string[100];  
for (int i = 0; i < 100; i++)  
{  
   reader[i] = txtReader.ReadLine();  
   if (reader[i] == null)  
       return;  
}  
把txt里面的内容读到一个数组中

------解决方案--------------------
探讨

能先读后判断吗,哈哈/ 


  string[] line=File.ReadAllLines("e:\a.txt");
  int lines = line.Length;