Step by step study notes three, Strategy (the Strategy pattern) for the camp .NET design patterns

Strategy pattern defines a series of algorithms, each algorithm and encapsulates them, and that they may also be replaced with each other. Strategy mode allows algorithm independent of the clients that use it independently change. (Original: The Strategy Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable Strategy lets the algorithm vary independently from clients that use it..)

Context (scenarios):

1, requires the use of algorithms ConcreteStrategy provided.

2, internal maintenance instance of a Strategy.

3, is responsible for dynamically setting Strategy specific algorithm runs.

4, interaction and data transfer between the responsible with the Strategy.

Strategy (Strategy abstract class):

1, define a common interface, a variety of algorithms implemented in different ways this interface, Context this interface calls using different algorithms, using general or abstract class implements an interface.

ConcreteStrategy (specific policy class):

2, implements the interface defined in the Strategy, provide specific algorithm.

Now I installed to configure a computer when we buy a computer as an example to be a Strategy Mode:

FIG look use case:

First, a new Computer.cs:

   public abstract class Computer
    {
       public abstract string MainBoard();

       public abstract string Cpu();

       public abstract string PhenoType();

       public abstract string Memory();

       public abstract string HardDisk();

       public abstract string Display();

      
    }

 Then New lenovo.cs:

public  class lenovo:Computer
    {

        public override string MainBoard()
        {
            return "华硕880G系列";
        }

        public override string Cpu()
        {
            return "闪龙双核180(2.4GHz)";
        }

        public override string PhenoType()
        {
            return "集成高性能显卡";
        }

        public override string Memory()
        {
            return "1G DDRIII";
        }

        public override string HardDisk()
        {
            return "500G";
        }

        public override string Display()
        {
            return "19寸宽屏液晶显示器";
        }
    }

 And then build HP.cs:

 public  class HP:Computer
    {
        public override string MainBoard()
        {
            return "ATI RS482";
        }

        public override string Cpu()
        {
            return "速龙 64位 x2 双核5000+";
        }

        public override string PhenoType()
        {
            return "NV G310 512M";
        }

        public override string Memory()
        {
            return "2G DDR2 667 ";
        }

        public override string HardDisk()
        {
            return "3200G";
        }

        public override string Display()
        {
            return "19寸宽屏液晶显示器";
        }
    }

And then buy a new computer class BuyComputer.cs:

public  class BuyComputer
    {
        private Computer _computer;

        public BuyComputer(Computer computer)
        {
            _computer = computer;
        }
        public string ShowComputerConfigure()
        {
            StringBuilder strCom = new StringBuilder();
            strCom.AppendLine("你的电脑配置如下:");
            strCom.AppendLine("主板是:" + _computer.MainBoard());
            strCom.AppendLine("处理器是:" + _computer.Cpu());
            strCom.AppendLine("显卡是:" + _computer.PhenoType());
            strCom.AppendLine("内存是:" + _computer.Memory());
            strCom.AppendLine("硬盘是:" + _computer.HardDisk());
            strCom.AppendLine("显示器是:" + _computer.Display());
            strCom.AppendLine("己组装完成");

            return strCom.ToString();
        }

    }

Then call it:

 public partial class Run : Form
    {
        public Run()
        {
            InitializeComponent();
        }

        private void btnRun_Click(object sender, EventArgs e)
        {
            BuyComputer myBuy = new BuyComputer(new lenovo());
             rtbResult.AppendText(myBuy.ShowComputerConfigure());
            myBuy = new BuyComputer(new HP());
             rtbResult.AppendText(myBuy.ShowComputerConfigure());
        }
    }

Results are as follows:

Your computer configuration is as follows:
motherboard is: ASUS 880G series
processors: Sempron binuclear 180 (2.4GHz)
card is: integrated high-performance graphics
memory is: 1G DDRIII
hard is: 500G
display is: 19-inch widescreen LCD monitor
hexyl assembly complete
your computer configuration is as follows:
motherboard is: ATI RS482
processor: Athlon 64 5000 + x2 dual core
chip is: NV G310 512M
memory is: 2G DDR2 667
drives are: 3200G
display is: 19-inch widescreen LCD monitor
hexyl assembly carry out

Summary: Strategy pattern and abstract factory pattern is like, except that the multi-mode strategy a unified interface class, here is BuyComputer.

Welcome Paizhuan.

Reproduced in: https: //www.cnblogs.com/springyangwc/archive/2011/04/02/2002809.html