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.
About this task
To add a change event to a transition:
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.