کد خواندن و نوشتن فایلهای متنی

using System.IO;

private void CreateTextFile()
{
    using (FileStream fs = new FileStream("C:\\test.txt", FileMode.Create))
    {
        using (StreamWriter w = new StreamWriter(fs, Encoding.UTF8))
        {
            w.WriteLine(124.23M);
            w.WriteLine("Salaam!");
            w.WriteLine('!');
        }
    }
}
 
private string ReadFromTextFile()
{
    StringBuilder sb = new StringBuilder();
    using (FileStream fs = new FileStream("C:\\test.txt", FileMode.Open))
    {
        using (StreamReader r = new StreamReader(fs, Encoding.UTF8))
        {
            sb.AppendLine(r.ReadLine());
            sb.AppendLine(r.ReadLine());
            sb.AppendLine(r.ReadLine());
        }
    }
    return sb.ToString();
}