public Form1()
 {
     InitializeComponent();
     // This is 'registering' the ComboBoxValueChanged method to the delegate.
     // So, when the delegate is invoked (called), this method gets executed.
     notifyDelegate += new NotifyComboBoxChange(ComboBoxValueChanged);
 }
 public FormA(NotifyComboBoxChange notify)
 {
     InitializeComponent();
     notifyDel = notify;
 }