In UML models, a change event
is an event that represents a condition. The condition is defined
by a Boolean-valued expression that triggers a transition when its
value changes from
false to
true.
Before you begin
Before you can add a trigger to
a transition, you must have a state machine diagram open in the
Modeling perspective.
Procedure
- Right-click a transition; then click .
- Complete one of the following steps:
- To create a new change event, click Create Change
Event, type a name, and press Enter.
- To select an existing change event, click Select
Existing Element, and in the Select Element window,
click a change event, and click OK. Type a
name and press Enter.
Results
The change event is added to the transition in the diagram
and in the
Project Explorer view. You can view
and modify details about the change event in the
Properties view,
on the Triggers page for the selected transition.