In sequence diagrams, you can add create,
destroy, synchronous and asynchronous messages to lifelines to represent
communication between objects. You can also specify the
signatures of messages.
- In the Palette,
click a message type.
- In the interaction frame, click
a source lifeline and drag the cursor to a target lifeline.
- Type a name for the message.
If you create a synchronous message, a return message is created
automatically.
Note: You can delay an asynchronous message by dragging
the asynchronous message first horizontally and then vertically across
existing messages to the target lifeline where you want to terminate
the message.
Tip: You can also assign an operation
to a message in an existing diagram. In the navigation view, click
an operation and drag it onto a message in the interaction frame.
The operation must belong to the target instance of the object or
be visible to and in scope of the operation in an object.