WPF

class Farmonicior
  {
      private string sourcpath = string.Empty;

      public string SourcePath
      {
          get
          {
              if (sourcpath==string.Empty)
                  global::System.Windows.MessageBox.Show("The Source Cannot be Empty!!!");
              return sourcpath;
          }
          set {sourcpath = value;}
      }


      private string resultFolder = string.Empty;
      /// <summary>
      /// If this is empty, the source folder will be used
      /// </summary>
      public string ResultFolder
      {
          get
          {
              if ( resultFolder == string.Empty)
              {
                  FileInfo fi = new FileInfo(sourcpath); //use the source forder path
                  resultFolder = fi.DirectoryName;
              }
              return resultFolder;
          }
          set { resultFolder = value; }

      }

      /// <summary>
      /// Create the files with the customer conditions
      /// </summary>
      public void FilesWork()
      {
          string line = string.Empty;
          List<string> LinesList = new List<string>();
          try
          {
              StreamReader StrRdr = new StreamReader(SourcePath);
              while ((line = StrRdr.ReadLine()) != null )
              {
                  if (line.StartsWith("LN"))
                  {
                      LinesList.Add(line);
                  }
              }
              StrRdr.Close();
          }
          catch (Exception ErrExc)
          {
              System.Windows.MessageBox.Show(ErrExc.Message,"Read Source.");
          }

           Singleton.Instance.ProgressBarMAX = LinesList.Count;

          try
          {
              Singleton.Instance.ProgressBarVAL = 0;
              string year = DateTime.Today.ToString("yy"); //year format 13, not 2013
              foreach (string item in LinesList)
              {

                  string[] lineArr = item.Split('|');
                  string newfile = string.Format(@"{0}\{1}_{2}.txt", ResultFolder, lineArr[2], lineArr[3]);
                  Singleton.Instance.NewFilesPath.Add(newfile);
                  StreamWriter StrWtr = new StreamWriter(newfile, false);
                  StrWtr.WriteLine(string.Format("yy"));
                  StrWtr.WriteLine(string.Format("nn|tttttt"));

                  if (lineArr.Length == 8)
                  {
                      if (lineArr[7] != "")
                          StrWtr.WriteLine("qwertyui");
                      else
                          StrWtr.WriteLine("poiuytrewq");
                  }
                  else
                      StrWtr.WriteLine(string.Format("HR|{0}|{1}", lineArr[3], year));

                  StrWtr.WriteLine(string.Format("RTG|{0}|{1}", lineArr[5], lineArr[6]));
                  StrWtr.WriteLine("END");
                  StrWtr.Close();
                  Singleton.Instance.ProgressBarVAL++;
              }
          }
          catch (Exception ErrExc)
          {
              System.Windows.MessageBox.Show(ErrExc.Message,"Create Files.");
          }
      }
  }

 public partial class MainWindow : Window,INotifyPropertyChanged
    {
        Farmonicior hrm = new Farmonicior();//implemetn the interface here

        public MainWindow()
        {
            InitializeComponent();

        }

        private void button1_Click(object sender, RoutedEventArgs e)//SourceFileTxtBx
        {
            PrgrssBar1.Value = 0;
            // Create OpenFileDialog 
            Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
            // Set filter for file extension and default file extension 
            dlg.DefaultExt = ".txt";
            dlg.Filter = "Text documents (.txt)|*.txt";
            // Display OpenFileDialog by calling ShowDialog method 
            Nullable<bool> result = dlg.ShowDialog();
            // Get the selected file name and display in a TextBox 
            if (result == true)
            {
                string filename = dlg.FileName;
                SourceFileTxtBx.Text = filename;
                hrm.SourcePath = filename;
                ResulFolderTxtBx.Text = hrm.ResultFolder;
            }
        }

        private void button2_Click(object sender, RoutedEventArgs e) //ResulFolderTxtBx 
        {
            string selectedFolder = string.Empty;
            FolderBrowserDialog selectFolderDialog = new FolderBrowserDialog();
            selectFolderDialog.ShowNewFolderButton = true;
            if (selectFolderDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                Singleton.Instance.NewFilesPath.Clear();
                FilesNamesTxtBx.Clear();
                Singleton.Instance.ProgressBarVAL = 0;
                
                selectedFolder = selectFolderDialog.SelectedPath;
                ResulFolderTxtBx.Text = selectedFolder;
                hrm.ResultFolder = selectedFolder;
            }
        }

        private void GoBttn_Click(object sender, RoutedEventArgs e)
        {
            PrgrssBar1.Maximum = Singleton.Instance.ProgressBarMAX;
            if (hrm.SourcePath == string.Empty)
                System.Windows.MessageBox.Show("Must Select a source file");
            else
            {
                //Thread td = new Thread(hrm.FilesWork);
                // hrm.FilesWork();

               foreach (string item in Singleton.Instance.NewFilesPath)
               {
                   FilesNamesTxtBx.AppendText(item + Environment.NewLine);
               }
               FilesWork();
                //td.Start();
                //progresBarTxtBx.Text = "DONE!";
            }

        }
        
        public void ProgressBarStep()//I call this function from the set of the singleton Maxvalue prop
        {
            PrgrssBar1.Value++;
        }

        internal void updateProgressbarMax()//(int max)// colled from the set of the singleton progressbarmax
        {
            PrgrssBar1.Maximum = Singleton.Instance.ProgressBarMAX;//max; 
            progresBarTxtBx.Text = "Total files: " + Singleton.Instance.ProgressBarMAX.ToString();  //a textbox somewhere
        }

}

public sealed class Singleton
{
    MainWindow MW = new MainWindow();
    static readonly Singleton _instance = new Singleton();

    public static Singleton Instance
    {
        get { return _instance; }
    }

    int progBarVal;// = Properties.Settings.Default.upLeftX;
    public int ProgressBarVAL
    {
        get { return progBarVal; }
        set
        {
            progBarVal = value;
            MW.ProgressBarStep();
        }
    }

    int progBarMax;// = Properties.Settings.Default.upLeftY;
    public int ProgressBarMAX
    {
        get { return progBarMax; }
        set
        {
            progBarMax = value;
            MW.updateProgressbarMax();
        }
    }


    List<string> newfilePath = new List<string>();
    public List<string> NewFilesPath
    {
        get { return newfilePath; }
        set
        {
            newfilePath = value;

        }
    }

    private Singleton()
    {
    }
}