Bạn có thể muốn nhìn thấy một danh sách của tất cả các lớp và các hoạt động tham gia trong một trường hợp sử dụng cụ thể. Khi dự án tiến triển và bạn thêm hoặc thay đổi yêu cầu, nó có thể rất hữu ích để biết những lớp học có thể bị ảnh hưởng bởi sự thay đổi. Trong ví dụ hãng hàng không của chúng tôi, | Chapter 4 Use Cases and Actors Viewing Participants of a Use Case You may want to see a listing of all of the classes and operations that participate in a particular use case. As the project progresses and you add or change requirements it can be very helpful to know what classes might be affected by the change. In our airline example we will need to know which classes are used by which use case as the requirements evolve and the use cases change. Even after the system is complete you may need an inventory of which classes are included in each use case. As the system moves into maintenance mode you will need to control the scope of upgrades and changes. In Rose you can view the use case participants using the Report menu. To view the classes and operations participating in a use case 1. Select the use case on a Use Case diagram. 2. Select Report Show Participants in UC. 3. The Participants window will appear as shown in Figure . Figure Use case Participants window Checking the Display Parent check box will display the package that owns each of the classes participating in the use case. The parent appears in parentheses after the class or operation name. Checking the Display Type check box will add a notation next to each item in the list box to let you know whether the item is a class or an operation. The type appears in parentheses after the class or operation name. Use the Components Classes and Operations check boxes to control whether components classes operations or all three appear in the list box. Use the Open It button to view the specifications for an item in the list and use the Goto It button to select the item in the browser. Assigning a Use Case Stereotype In UML stereotypes are used to help you categorize your model elements. Say for example you had two primary types of use cases type A and type B. You can create two new use case stereotypes A and B. Stereotypes aren t used very often for use cases they are used more for other model elements
