using System;
using System.IO;

namespace ConsoleApplication2
{
 /// <summary>
 /// Summary description for Class2.
 /// </summary>
 public class Class1
 {
  private const string FILE_NAME="MyFile.txt";
  public static void Main(String[] args)
  {
   StreamWriter sr;
   string report;
   if(File.Exists(FILE_NAME)) //如果文件存在,则创建File.AppendText对象
   {
    sr=File.AppendText(FILE_NAME);
    report="appended";
   }
   else  //如果文件不存在,则创建File.CreateText对象
   {
    sr=File.CreateText(FILE_NAME);
    report="created";
   }
   
   sr.WriteLine("This is my first file.");
   Console.WriteLine("{0} {1}",FILE_NAME,report);
   sr.Close();
  }
 }
}