A message can create an object if it is the first message received by the object and you set its Action property to "Create".
You cannot create an actor or use the create action with a recursive message.
When a message creates an object in a sequence diagram, the message is drawn with its arrowhead on the object; both object and message are at the same level.
In a sequence diagram, you can also create a create message automatically as follows:
- Click the Message tool in the Palette.
- Click the lifeline of the sender object or actor and, while holding down the mouse button, drag the cursor towards the receiver object.
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Release the mouse button on the object symbol of the receiver (and not on its lifeline).
If the message is the first message to be received by the receiver object, the receiver object symbol moves down to line up with the create message.
