设计模式之建造者模式

Builder Design Pattern

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definition  UML diagram  participants

sample code in C#

definition Separate the construction of a complex object from its representation so that the same construction process can create different representations. Frequency of use:   medium low

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UML class diagram

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participants

    The classes and/or objects participating in this pattern are:

• Builder  (VehicleBuilder)
• • specifies an abstract interface for creating parts of a Product object
• ConcreteBuilder  (MotorCycleBuilder, CarBuilder, ScooterBuilder)
• • constructs and assembles parts of the product by implementing the Builder interface
  • defines and keeps track of the representation it creates
  • provides an interface for retrieving the product
• Director  (Shop)
  • constructs an object using the Builder interface
• Product  (Vehicle)
  • represents the complex object under construction. ConcreteBuilder builds the product's internal representation and defines the process by which it's assembled
  • includes classes that define the constituent parts, including interfaces for assembling the parts into the final result

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sample code in C#

This structural code demonstrates the Builder pattern in which complex objects are created in a step-by-step fashion. The construction process can create different object representations and provides a high level of control over the assembly of the objects.

Show code

// Builder pattern -- Structural example