This interface allows a BlackBerry® device application to listen for changes to Field objects (for example, when a user clicks a button or selects a check box) and perform appropriate actions in response to a change. A class that implements this interface must implement fieldChanged(Field field, int context), which contains the code that manages the change. To specify a listener for a Field, you must invoke Field.setChangeListener(FieldChangeListener listener). You can specify a listener for any Field subclass, such as the Screen class or Manager class.
The sample application implements fieldChanged(Field field, int context) to listen for changes to the ObjectChoiceField object.