Behavioral Diagrams
The UML’s behavioral diagrams are used to visualize, specify, construct, and document the dynamic aspects of a system. You can think of the dynamic aspects of a system as representing its changing parts. Just as the dynamic aspects of a house encompass airflow and traffic through the rooms of a house, so too do the dynamic aspects of a software system encompass such things as the flow of messages over time and the physical movement of components across a network.
行为图
UML的行为图被用于可视化、具体化，结构化和文档化系统动态的方面。你可以将系统动态的方面想象成表达它正在改变的部分。就像一个房子动态的方面包括空气流通和房子里的房间之间的连通，一个软件系统动态的方面同样也包括诸如随着时间流动的消息流和在网络中移动的组件这类的事物。
The UML’s behavioral diagrams are roughly organized around the major ways you can model the dynamics of a system.
Organizes the behaviors of the system
Focuses on the time ordering of messages
3.Communication diagram
Focuses on the structural organization of objects that send and receive messages
Focuses on the changing state of a system driven by events
Focuses on the flow of control from activity to activity
UML的行为图大致有以下几类，它们是你可以建模系统动态方面的主要途径：
组织系统的行为
重点是以时间为顺序的消息
重点是对象的结构组织发送和接收消息
重点是通过事件驱动系统状态的改变
重点是活动与活动之间的控制流动。
Use Case DiagramAuse case diagram shows a set of use cases and actors (a special kind of class) and their relationships. You apply use case diagrams to illustrate the static use case view of a system. Use case diagrams are especially important in organizing and modeling the behaviors of a system.
Interaction diagramis the collective name given to sequence diagrams and communication diagrams. All sequence diagrams and communication diagrams are interaction diagrams, and an interaction diagram is either a sequence diagram or a communication diagram. These diagrams share the same underlying model, although in practice they emphasize different things. (Timing diagrams are another kind of interaction diagram that are not covered in this book.)
用例图
Sequence DiagramAsequence diagram is an interaction diagram that emphasizes the time ordering of messages. A sequence diagram shows a set of roles and the messages sent and received by the instances playing the roles. You use sequence diagrams to illustrate the dynamic view of a system.
序列图
Communication DiagramAcommunication diagramis an interaction diagram that emphasizes the structural organization of the objects that send and receive messages. A communication diagram shows a set of roles, connectors among those roles, and messages sent and received by the instances playing the roles. You use communication diagrams to illustrate the dynamic view of a system.
通讯图
State DiagramAstate diagram shows a state machine, consisting of states, transitions, events, and activities. You use state diagrams to illustrate the dynamic view of a system. They are especially important in modeling the behavior of an interface, class, or collaboration. State diagrams emphasize the event-ordered behavior of an object, which is especially useful in modeling reactive systems.
状态图
Activity DiagramAnactivity diagram shows the flow from step to step within a computation. An activity shows a set of actions, the sequential or branching flow from action to action, and values that are produced or consumed by actions. You use activity diagrams to illustrate the dynamic view of a system. Activity diagrams are especially important in modeling the function of a system. Activity diagrams emphasize the flow of control within the execution of a behavior.
活动图
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