策略模式 之c#,c++,java,php
策略模式是目前我工作中比较常用的模式
下面贴出搜集各种语言的版本，记得我当初刚开始的时候，只会C#，别的语言看不明白，不知道现在还有没有人有我当年的烦恼!
所以在这里我提供c#,C++,java,php四种版本，本来想写python版本，可惜自己不太懂，怕弄错让大家笑话
首先来个策略模式的大致讲解,定义一系列的算法，把他们一个个封装起来，并且使他们可相互替换，本模式使得算法可独立于使用它的客户而变化
客户端知道要调用具体哪个算法，由客户端决定使用的算法,算法可以独立于客户端自由的变动
如下图:
C#版本策略模式:
using System;
using System.Collections.Generic;
using System.Text;
namespace 策略模式
{
class Program
{
static void Main(string[] args)
{
Context context;
context = new Context(new CreateStrategyA());
context.ContextInterface();
context = new Context(new CreateStrategyB());
context.ContextInterface();
context = new Context(new CreateStrategyC());
context.ContextInterface();
Console.Read();
}
}
abstract class Strategy
{
public abstract void AlgoInterface();
}
class CreateStrategyA : Strategy
{
public override void AlgoInterface()
{
Console.WriteLine("Called CreateStrategyA.AlgoInterface()");
}
}
class CreateStrategyB : Strategy
{
public override void AlgoInterface()
{
Console.WriteLine("Called CreateStrategyB.AlgoInterface()");
}
}
class CreateStrategyC : Strategy
{
public override void AlgoInterface()
{
Console.WriteLine("Called CreateStrategyC.AlgoInterface()");
}
}
class Context
{
Strategy strategy;
public Context(Strategy strategy)
{
this.strategy = strategy;
}
public void ContextInterface()
{
strategy.AlgoInterface();
}
}
}
c++版本策略模式
//策略基类
class COperation
{
public:
int m_nFirst;
int m_nSecond;
virtual double GetResult()
{
double dResult=0;
return dResult;
}
};
//策略具体类—加法类
class AddOperation : public COperation
{
public:
AddOperation(int a,int b)
{
m_nFirst=a;
m_nSecond=b;
}
virtual double GetResult()
{
return m_nFirst+m_nSecond;
}
};
class Context
{
private:
COperation* op;
public:
Context(COperation* temp)
{
op=temp;
}
double GetResult()
{
return op->GetResult();
}
};
//客户端
int main()
{
int a,b;
char c;
cin>>a>>b;
cout<<”请输入运算符：;
cin>>c;
switch(c)
{
case ‘+’:
Context *context=new Context(new AddOperation(a,b));
cout<<context->GetResult()<<endl;
break;
default:
break;
}
return 0;
}
java版本策略模式
public interface Person {
public void speakLanguage();
}
public class Chinese implements Person {
public void speakLanguage() {
System.err.println("I speak Chinese!");
}
}
public class StrategyPerson {
private Person person;
public StrategyPerson(Person person){
this.person = person;
}
public void speakLanguage(){
person.speakLanguage();
}
}
public class TestMain {
public static void main(String[] args){
Person person = new Chinese();
StrategyPerson sp = new StrategyPerson(person);
sp.speakLanguage();
}
}
php版本策略模式
<?php
interface IStrategy
{
function filter( $record );
}
class FindAfterStrategy implements IStrategy
{
private $_name;
public function __construct( $name )
{
$this->_name = $name;
}
public function filter( $record )
{
return strcmp( $this->_name, $record ) <= 0;
}
}
class RandomStrategy implements IStrategy
{
public function filter( $record )
{
return rand( 0, 1 ) >= 0.5;
}
}
class UserList
{
private $_list = array();
public function __construct( $names )
{
if ( $names != null )
{
foreach( $names as $name )
{
$this->_list []= $name;
}
}
}
public function add( $name )
{
$this->_list []= $name;
}
public function find( $filter )
{
$recs = array();
foreach( $this->_list as $user )
{
if ( $filter->filter( $user ) )
$recs []= $user;
}
return $recs;
}
}
$ul = new UserList( array( "Andy", "Jack", "Lori", "Megan" ) );
$f1 = $ul->find( new FindAfterStrategy( "J" ) );
print_r( $f1 );
$f2 = $ul->find( new RandomStrategy() );
print_r( $f2 );
?>
有了解python 的童鞋，希望可以帮忙补充进来
