How to use C# BinaryReader Class in C#

How to use C# BinaryReader Class

using System;

using System.Windows.Forms;

using System.IO;

using System.Text;

                                

namespace WindowsApplication1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            FileStream readStream ;

            string msg = null;

            try

            {

                readStream = new FileStream("c:\\csharp.net-informations.dat", FileMode.Open);

                BinaryReader readBinary = new BinaryReader(readStream);

                msg = readBinary.ReadString();

                MessageBox.Show(msg);

                readStream.Close();

            }

            catch (Exception ex)

            {

                MessageBox.Show (ex.ToString());

            }

        }

    }

}