Read binary file using file pointer

using System;
using System.IO;
using System.Text;
 
 
class Class1{
  static void Main(string[] args)  {
         byte[] byData = new byte[100];
         char[] charData = new Char[100];
 
 
         try {
            FileStream aFile = new FileStream("practice.txt",FileMode.Open);
            aFile.Seek(55,SeekOrigin.Begin);
            aFile.Read(byData,0,100);
         }
         catch(IOException e)
         {
            Console.WriteLine("An IO exception has been thrown!");
            Console.WriteLine(e.ToString());
            Console.ReadLine();
            return;
         }
 
 
         Decoder d = Encoding.UTF8.GetDecoder();
         d.GetChars(byData, 0, byData.Length, charData, 0);
 
 
         Console.WriteLine(charData);
         return;
  }
}