using System; 
using System.IO; 
public class TestReadFile 
{ 
    public static void Main(String[] args) 
    { 
        // Read text file C:\temp\test.txt 
        FileStream fs = new FileStream(@c:\temp\test.txt , FileMode.Open, FileAccess.Read); 
        StreamReader sr = new StreamReader(fs);  
        
        String line=sr.ReadLine();
        while (line!=null)
        {
            Console.WriteLine(line);
            line=sr.ReadLine();
        }  
        
        sr.Close();
        fs.Close();
    } 
} 

using System; 
using System.IO; 
public class TestWriteFile 
{ 
    public static void Main(String[] args) 
    { 
        // Create a text file C:\temp\test.txt 
        FileStream fs = new FileStream(@c:\temp\test.txt , FileMode.OpenOrCreate, FileAccess.Write); 
        StreamWriter sw = new StreamWriter(fs); 
        // Write to the file using StreamWriter class 
        sw.BaseStream.Seek(0, SeekOrigin.End); 
        sw.WriteLine( First Line ); 
        sw.WriteLine( Second Line); 
        sw.Flush(); 
    } 
}