C#

public partial class frmChild : Form
   {
   // Signal file change happened
   public event EventHandler Changed;

   protected virtual void OnChanged(EventArgs e)
      {
      EventHandler eh = Changed;
      if (eh != null)
         {
         eh(this, e);
         }
      }

   private void DoSomethingToChangeData()
      {
      OnChanged(null);
      }
   }

public frmParent()
     {
     frmChild.Change += new frmChange.ChangeHandler(Changed);
     }

 private void ShowChildForm()
     {
     // Link in his event so if it changes, we detect it.
     frmChild fd = new frmChild();
     fd.ShowDialog();
     }

 //
 // Fired when the file is changed at a lower level.
 //
 private void Changed(object sender, EventArgs e)
     {
     }

public partial class frmOther : Form
     {
     public frmOther()
         {
         InitializeComponent();
         }

     public event EventHandler Changed;

     private void butGo_Click(object sender, EventArgs e)
         {
        EventHandler ch = Changed;
        if (ch != null)
           {
           ch(this, new ChangedArgs(tbData.Text));
           }
         }
     }

 public partial class ChangedArgs : EventArgs
     {
     public string strData;
     public ChangedArgs(string str)
         {
         strData = str;
         }
     }

public partial class frmTextBox : Form
    {
    frmOther otherForm = new frmOther();
    public frmTextBox()
        {
        InitializeComponent();
        }

    private void frmTextBox_Load(object sender, EventArgs e)
        {
        otherForm.Changed += new EventHandler(Changed);
        otherForm.Show();
        }

    private void Changed(object sender, EventArgs e)
        {
        ChangedArgs ca = e as ChangedArgs;
        if (ca != null)
            {
            tbData.Text = ca.strData;
            }
        }
    }

public event EventHandler MyEvent;

protected virtual void OnMyEvent(EventArgs e)
{
    EventHandler eh = MyEvent;
    if(eh != null)
        eh(this, e);
}

public class MyEventArgs : EventArgs
{
    private int value;

    public MyEventArgs(int value)
    {
        this.value = value;
    }

    public int Value
    {
        get { return value; }
    }
}

GDavy wrote:

forgot to commit...

//rebuild the databinding for the textbox
txtROE.DataBindings.Clear();
Binding oBinding = new Binding("Text", oFSet, "ROE");
oBinding.FormatString = "#,#.00";
oBinding.FormattingEnabled = true;

public int MyProp
{
  get{return _myProp;}
  set
  {
    _myProp = MyProp  value; //sorry was too fast posting here :)
    NotifyPropertyChanged("MyProp"); //ok
    NotifyPropertyChanged("myProp"); // not ok... no error but propertychanged will not be forwarded to controls...
  }
}
        #region INotifyPropertyChanged Members

        protected void NotifyPropertyChanged(String propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
                handler(this, new PropertyChangedEventArgs(propertyName));
        }
        #endregion