Teach you how to use start uml to draw Use Case Diagrams and uml use cases

Teach you how to use start uml to draw Use Case Diagrams and uml use cases

I have recently prepared to study volley's source code, but I have read some blogs on the Internet. They all work with the diagram. This looks more intuitive and the analysis logic is also good, what kind of diagrams can clearly analyze the relationships between various types and how to extract them. So I first learned the modeling tool software. I used start uml as a drawing tool, start uml can draw example diagram Class Diagram time sequence diagram deployment diagram, where one by one to learn patiently, one breath can not eat a fat man, learning you insist on!

Use case diagram Overview:

A Dynamic View composed of participants, use cases, and relationships between them to describe system functions is called a use case diagram.

Participant: A person, system, or device that exists outside the system and interacts directly with the system.

Categories of participants:

Participants can be divided into primary participants and secondary participants based on whether or not to use the core functions of the system.

Participants are represented in the start uml tool:

Case Overview:

Is the function provided by the system for participants. For the use case naming, we can give the use case a simple name with a general name. It is generally a name with attention. The use case is represented by an ellipse in the drawing. The name and solid arrow of the use case are attached to the oval, which are used to connect the participants and use cases in the use case diagram. the use case is directed to the use case.

In start uml, use cases are represented as follows:

The relationship between the participant and the use case is that the participant points to the use case and uses the system function with an arrow.

There are also relationships between use cases and use cases, which can be divided into three types:

1: generalization indicates a general and special relationship.

In the generalization relationship, the subuse case inherits the behavior and meaning of the parent use case. The subuse case can also add new behaviors and meanings or the behavior and meaning in the parent use case.

The following shows a general relationship diagram between use cases in ticket booking mode:

 

2: include relationship

It refers to the relationship between two use cases. The behavior of one use case (referred to as the Basic use case, base use case) contains the behavior of another use case (referred to as the include case, define sion case ).

3: Extended relationship

Encapsulate a relatively independent and optional action in the base case with the Extension case, and then extend it from the Extension Point declared in the base case, this makes the basic case behavior more concise and more concentrated.

The next article describes how to write a class chart