File Stream C#

using System;
using System.IO;
public class SWBuff 
{
    public static void Main(String[] args)
    {
            string logFile = "a.log";
            string fileName = "a.log";
      string textToAdd = "asdf";
            FileStream fs = new FileStream(fileName, FileMode.CreateNew, FileAccess.Write, FileShare.None);
      
            StreamWriter swFromFile = new StreamWriter(logFile);
            swFromFile.Write(textToAdd);
            swFromFile.Flush();
            swFromFile.Close();
    }
}