为什么即使用例不被认为是面向对象的，我们还是在面向对象的分析和设计中使用UseCase图?
UML notations says, Usecases are drawn to point out the functional requirements in the Problem Domain, it by no means gives the information about object or class as Data Flow Diagrams or Entity Relationship diagrams. But also why do we use Usecase Diagrams in object oriented analysis and design even if Usecases are not considered as Object oriented.
用例图旨在阐明系统的主要功能，并强调将后者表示为blackBox的观点.仅存在于执行单一任务的情况下；向演员提供承诺的服务.
Use case diagram is meant to shed light on the main functionalities of the system , and emphasis the perspective presenting the latter as a blackBox merely existing for a sole mission;deliver to the actor the Promised service .
在这一点上，我们并不真正关心OOP realy，因为您可以明确地将用例图用于任何其他类型的分析.
At this point we don't realy care about OOP realy , as you can definetly use Use case diagram for any other type of analysis.
UML 只是一组可视化工具，用于统一表达系统的不同视角. 如果您使用的是统一流程，则建议首先识别用例，然后将每个用例分解为协作实体(类)，并利用 Class建立它们之间的静态协作.图工具箱.
UML is just a set of visual tools to allow a unified expression of different perspective of the system. In Case you are using The Unified Process it advocates to start with identifiying the use cases first then explode every use case into collaborative entities (classes) and establish the static collaboration between them by harnessing the Class Diagram toolbox.