how to use streamwriter/streamreader?

To write the listbox items to a file:

            FileStream dFile = new FileStream("C:\\temp\\data.txt", FileMode.OpenOrCreate);
           
            StreamWriter sw = new StreamWriter(dFile); //write data to file

            foreach (object item in listBox1.Items)
            {
                sw.WriteLine("{0}", item.ToString());
            }

            sw.Close();


To load the listbox from the file:

           FileStream dFile = new FileStream("C:\\temp\\data.txt", FileMode.Open);
           
           StreamReader sr = new StreamReader(dFile); // read data from file
            string item;

            while ((item = sr.ReadLine()) != null)
            {
                listBox1.Items.Add(item);
            }

            sr.Close();