Demonstrate random access file : FileStream « File Directory Stream « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. File Directory Stream
3. FileStream

using System; 
using System.IO;  
 
class MainClass { 
  public static void Main() { 
    FileStream f; 
    char ch; 
 
    try { 
      f = new FileStream("random.dat", FileMode.Create); 
    } 
    catch(IOException exc) { 
      Console.WriteLine(exc.Message); 
      return ; 
    } 
 
    // Write the alphabet.      
    for(int i=0; i < 26; i++) { 
      try { 
        f.WriteByte((byte)('A'+i)); 
      }  
      catch(IOException exc) { 
        Console.WriteLine(exc.Message); 
        return ; 
      } 
    } 
 
    try { 
      f.Seek(0, SeekOrigin.Begin); // seek to first byte 
      ch = (char) f.ReadByte(); 
      Console.WriteLine("First value is " + ch); 
 
      f.Seek(1, SeekOrigin.Begin); // seek to second byte 
      ch = (char) f.ReadByte(); 
      Console.WriteLine("Second value is " + ch); 
 
      f.Seek(4, SeekOrigin.Begin); // seek to 5th byte 
      ch = (char) f.ReadByte(); 
      Console.WriteLine("Fifth value is " + ch); 
 
      Console.WriteLine(); 
 
    }  
    catch(IOException exc) { 
      Console.WriteLine(exc.Message); 
    } 
  
    Console.WriteLine(); 
    f.Close(); 
  } 
}

First value is A
Second value is B
Fifth value is E