simple file righting and reading

using System; 

using System.Collections.Generic; 

using System.ComponentModel;

 using System.Data;

 using System.Drawing; 

using System.Linq; 

using System.Text;

 using System.Windows.Forms;

 using System.IO;//used for io operations this name space is must for file manipulation namespace WindowsFormsApplication3

 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { saveFileDialog1.ShowDialog();//for showing savedialog box FileStream f = new FileStream(saveFileDialog1.FileName+".txt", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite); StreamWriter sr = new StreamWriter(f); sr.Write(richTextBox1.Text); sr.Close(); f.Close(); richTextBox1.Clear(); } private void button2_Click(object sender, EventArgs e) { string s = "text file|*.txt";//filter varible OpenFileDialog op = new OpenFileDialog(); op.Filter = s;//providing filter op.ShowDialog(); StreamReader sr = new StreamReader(new FileStream(op.FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)); richTextBox1.Text= sr.ReadLine(); sr.Close(); } } }