NET design pattern instances Simple Factory mode (Factory pattern)

Introduction of Simple Factory model (Bref Introduction)

The advantage of simple Factory pattern is that the factory class contains the necessary logical judgments, dynamically instantiating related classes based on the client's selection criteria, and for the client, to remove the reliance on the specific product

Ii. Problem Solving (what to Solve)

When a client instantiates an object, it does not need to be concerned about which subclass of the object is instantiated.

Three, simple factory model Analysis 1, simple factory model structure

I Product Interface: Abstract Product class

concreteproduct class : Specific implementation of product classes

Simple Factory Simple Factory class

Four Example Analysis (Example) 1, scene

A simple calculator with simple add and subtract operations. Structure as shown

simplefactory: Simple Factory class.

Operation: Abstract Operation class

addoperation: addition operation

suboperation: subtraction operation

2. Code

1, abstract Operation class operation, and its specific implementation class Addoperation, suboperation

<summary> Abstract Operation class </summary> Public abstract class operation { public int Numbera; public int numberb; public abstract int GetResult (); } <summary> Addition operation </summary> public class Addoperation:operation { public override int GetResult () { Return (This.numbera + this.numberb); } } <summary> Subtraction operation </summary> public class Suboperation:operation { public override int GetResult () { return (THIS.NUMBERA-THIS.NUMBERB); } }

2, Simple factory class Simplefactory

<summary> Simple Factory class </summary> public class Simplefactory { public static Operation CreateOperation (String operation) { Operation o = null; Switch (operation) { Case "+": o = new Addoperation (); Break Case "-": o = new Suboperation (); Break } return o; } }

3 , client-side code

static void Main (string[] args) { Operation Operation1 = simplefactory.createoperation ("+"); Operation1.numbera = 10; Operation1.numberb = 20; Console.WriteLine ("{0}+{1}={2}", Operation1.numbera, Operation1.numberb, Operation1. GetResult ()); Operation Operation2 = Simplefactory.createoperation ("-"); Operation2.numbera = 10; Operation2.numberb = 20; Console.WriteLine ("{0}-{1}={2}", Operation2.numbera, Operation2.numberb, Operation2. GetResult ()); Console.read (); }

3. Example running result

V. Summary (Summary)

Simple Factory mode is a relatively simple design mode, this paper describes the concept of this mode and its design structure diagram, and finally a calculator example is described.

Reprinted from: http://www.cnblogs.com/ywqu/archive/2010/01/06/1640026.html

NET design pattern instances Simple Factory mode (Factory pattern)