c sharp中实现分行写数据到Txt中，以及读取文件中任一行数据

using System;
using System.Text;
using System.IO;
namespace TxtReadWrite
{
 class APPlicationEvent
{
    public static void Main(string[] agrs)
{
   SaveTxt(100,"E:/3.txt");
   GetCertainLineTxt(120,"E:/3.txt");
}
public static void SaveTxt(int count,string path)
{
   int [] aa=new int[count];
   string [] bb=new string[count];
for(int i=0;i<count;i++)
{
//string [] bb=new string[count];
aa[i]=i;
bb[i]=aa[i].ToString();
Console.WriteLine(bb[i]);
//File.WriteAllLines("E:/3.txt",bb[i]+'n',Encoding.UTF8);
}

File.WriteAllLines(path,bb,Encoding.UTF8);
}
public static void GetCertainLineTxt(int LineNum,string path)
{
string[] line=File.ReadAllLines(@path);
if(LineNum>=line.Length)
  Console.WriteLine("超出数据行数范围!");
else
  Console.WriteLine(line[LineNum]);
}
}
}