[ Pobierz całość w formacie PDF ]
.Delivery TipNote that the use cases created in the demonstration do not represent aThe step-by-stepcompleted model; this exercise is for demonstration purposes only.instructions for thisdemonstration are in theinstructor notes for thismodule.30 Module 4: Object-Oriented Design for Visual Basic.NETClass DiagramsTopic ObjectiveTo examine an example of aclass diagram.CustomerLead-inWe can put all of theserelationships together toform a class diagram.*1.*Order Order Item*ProductClass diagrams allow you to graphically put all of these relationships togetherDelivery Tipin a single place.With some refinement, class diagrams will help a designer orExplain the different parts ofdeveloper model the system in enough detail to enable code to be generated andthe class diagram, pointingdevelopment to begin.out that you could argue thata customer does not existThe ability to interpret a class diagram is vital in modern software development.unless it has at least oneThe slide shows that a single Customer class is associated with between zeroorder.and many Order classes.An Order class is made up of (or aggregated with)Order Item classes.The multiplicity for this relationship shows that there mustThe various relationshipsbe at least one Order Item for an Order to be valid, but that there can be anmay also provide discussionunlimited number of Order Items on the Order.Finally, each Order Item isbecause some could bedesigned as composition,associated with a single Product , but a Product can be associated with manyaggregation, or association.Order Items.Such discussion should beClass diagrams are also known as static structure diagrams in Visio andNotelimited because the purposein some other UML modeling tools.of the illustration is toexamine notation and theoverall look of a classdiagram. Module 4: Object-Oriented Design for Visual Basic.NET 31Creating Class DiagramsTopic ObjectiveTo point out the mainelements of a class diagramin Visio.Lead-inLet s take a look at a classdiagram inside Visio.Visio allows you to create extensive class diagrams that include the followingelements:Classes.Abstract classes or interfaces.Class attributes with accessibility (private, protected, and public), initialvalue, and stereotype (data type).Class operations with accessibility and parameters (detailed in the followingtext).Operation parameters with direction (in, out, inout, and return) andstereotype (data type).Relationships between objects, including association, dependency,aggregation, composition, and inheritance.These relationships includeattributes such as multiplicity, navigability, and stereotype.Notes to help stor e additional information.You can add descriptions to all of the objects listed above to fully documentyour model.You can also add any non-UML shapes from the various Toolboxtabs to create a freeform model.32 Module 4: Object-Oriented Design for Visual Basic.NETDemonstration: Creating Class DiagramsTopic ObjectiveTo demonstrate the creationof class diagrams in Visio.Lead-inClass diagrams areparticularly helpful forcreating Visual Basic.NETenterprise solutions.In this demonstration, you will learn how to create a class diagram in Visio.Delivery TipNote that the classes created in the demonstration do not represent a completedThe step-by-stepmodel.This exercise is for demonstration purposes only.instructions for thisdemonstration are in theinstructor notes for thismodule. Module 4: Object-Oriented Design for Visual Basic.NET 33Lab 4.1: Creating Class Diagrams from Use CasesTopic ObjectiveTo introduce the lab.Lead-inIn this lab, you will look atthe use cases for the Cargosystem.You will then createclass diagrams in Visio forthose use case descriptions.Explain the lab objectives [ Pobierz całość w formacie PDF ]