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()
    {
    }
}

Pete O'Hanlon wrote:

So, what is an attached event? Well, basically, it's an event that can be attached to another element without the other element having to be aware that this capability is present. If you think about it as being like an attached property for events then it starts to make sense. So, why do we have this? Well, it allows you to extend WPF through composition rather than inheritance.

<br />
   local:GrandChild.GrandChildRoutedEvClick="GrandChild_GrandChildRoutedEvClick"<br />

<br />
local:GrandChild.GrandChildAttachedEvClick="GrandChildAttachedEvClickHandler" <br />

<br />
[local:GrandChild x:Name="Junior" VerticalAlignment="Stretch" GrandChildRoutedEvClick="GrandChild_GrandChildRoutedEvClick"/]<br />

<Style TargetType="{x:Type TabItem}">
    <Setter Property="ContextMenu">
        <Setter.Value>
            <ContextMenu>
                <MenuItem Header="Close"
                            Command="{Binding CloseTabCommand}" 
                            CommandParameter="{Binding Path=PlacementTarget, RelativeSource={RelativeSource AncestorType=ContextMenu}}"/>
            </ContextMenu>
        </Setter.Value>
    </Setter>

private ICommand _CloseTabCommand;
public ICommand CloseTabCommand
{
    get
    {
        if (_CloseTabCommand == null)
            _CloseTabCommand = new RelayCommand<object>(p => closeTabExecuted(p), p => closeTabCanExecute(p));

        return _CloseTabCommand;
    }
}

private bool closeTabCanExecute(object obj)
{
    return true;
}
private void closeTabExecuted(object obj)
{
    TabManager.CloseActiveTab();
}