【文章內(nèi)容簡(jiǎn)介】 he class hierarchy in the same class or different classes, can use the same function name different operating functionality, which you can use the same call way to invoke these functions with the same name with different functions, such as p display (). Runtime polymorphism: the class inheritance hierarchy, classes may have different levels of the same name but different functions, the need to run stages according to which class level to determine the call object belongs to the same function. Will only function with the same specification as the virtual function, through object pointer or reference object to call virtual functions, to achieve the runtime polymorphism. UML and its application 1,.the system described in the UML model is posed of one or more views. UML provides 9 kinds of views: use case diagram, class diagram, object diagram, ponent diagram and configuration diagram, sequence diagram, collaboration diagram, state diagram and activity diagram. The 9 kinds of diagrams can be divided into a use case diagram, static view and dynamic view. 2, can also view is divided into five class diagram of UML, UML content is defined by the five class diagram: The first type is a use case diagram, describe system functionality from the user Angle, and points out the function of the operator. The second type is Static diagram (Static diagram), describe the Static structure of system, including the class diagram, object diagram. The third kind is Behavior diagrams (behaviors diagram) describing the dynamic Behavior of the system and to participate in the activities of the interaction relationship between objects, including activity diagrams and state diagrams. 面向?qū)ο?（文獻(xiàn)翻譯） 6 6 The fourth class is interaction diagrams (Interactive diagram) to describe the interaction relationship between objects, including the sequence diagram and collaboration diagram. The fifth class is Implementation diagram (Implementation diagram). Figure the view include the ponent diagram and configuration. 3, use case diagram Definition of the definition of a use case diagram: use case diagram from the Angle of the user use the system describes the system function of graphical representation methods. A Use Case (Use Case) is used to describe a function of the system requirements, it can accurately express the activists of interaction with the system and the system to provide a service. The Use Case of the contact: Use Case except contact activists have the Use Case .There is a certain link between, including: The generalization relationship: (a) a special Use Case with another, more general Use Case (b) Use contact: refers to a Use Case with another Use Case of functional behavior. (c) contain contact: a basic Use Case includes another public behavior of a Use Case. (d) expand contact: refers to a basic Use Case can be made by another functional behavior of the Use Case to expand. 4, the definition of a class diagram System class diagram is an expression of graphic class and its related logic (logic view). Class diagram is the core of objectoriented design, establishes the state diagram, collaboration diagram and other figure. Class and class relationships: the main related, aggregation/position, generalization/specialized, dependence, etc. 5, the definition of the sequence diagram Sequence diagram describes the dynamic collaboration between a group of interacting objects, which represents the plete one Operating behavior of passing messages between objects and the objects time sequence. The sequence diagram By the object class character, lifeline, activation period and message. 6, the definition of collaboration diagrams Behavior of a system is implemented by a group of objects, these objects are 面向?qū)ο?（文獻(xiàn)翻譯） 7 7 done through interaction and collaboration service system. Used to describe the implementation of certain services involving the relationship between objects and their dynamic views (including munication) are called Collaboration diagrams (Collaboration). Available UML collaboration diagrams to describe the business process. Collaboration diagram is different from the sequence diagram. 7, state diagram (StatechartDiagram) state diagram describes the definition of certain object may have in the process of system operation Status, and jump between different states and external trigger the jump Events. State diagram focuses on describe objects dynamically in its life cycle Behavior. Can also be used for the reaction type object modeling. 8, activity diagrams Definition: activity diagrams are used to describe business process or workflow system. Activity diagrams Is posed of a series of motion state, the movement state of the control can be switched from one state to another and the adjacent state. Activity diagram can also be said that decision state, condition, action of parallel execution and message specification, etc. Available strips of lane put th