add Observer Pattern

20.ObserverPattern/2.Code/AllyCenter.cpp

@@ -0,0 +1,55 @@
+#include "AllyCenter.h"
+#include "Observer.h"
+
+/***********   AllyCenter    ****************/
+AllyCenter::AllyCenter(){
+	printf("大吉大利，今晚吃鸡!\n");
+}
+
+// 加入玩家
+void AllyCenter::join(Observer* player){
+	if (playerList.size() == 4){
+		printf("玩家已满\n");
+		return;
+	}
+	printf("玩家 %s 加入\n", player->getName().c_str());
+	playerList.push_back(player);
+	if (playerList.size() == 4){
+		printf("组队成功，不要怂，一起上！\n");
+	}
+}
+// 移除玩家
+void AllyCenter::remove(Observer* player){
+	printf("玩家 %s 退出\n", player->getName().c_str());
+	//playerList.remove(player);
+}
+/***********   AllyCenter    ****************/
+
+
+/**********   AllyCenterController    *******/
+AllyCenterController::AllyCenterController(){
+
+}
+
+// 实现通知方法
+void AllyCenterController::notify(INFO_TYPE infoType, std::string name){
+	switch (infoType){
+	case RESOURCE:
+		for each (Observer* obs in playerList){
+			if (obs->getName() != name){
+				((Player*)obs)->come();
+			}
+		}
+		break;
+	case HELP:
+		for each (Observer* obs in playerList){
+			if (obs->getName() != name){
+				((Player*)obs)->help();
+			}
+		}
+		break;
+	default:
+		printf("Nothing\n");
+	}
+}
+/**********   AllyCenterController    *******/

20.ObserverPattern/2.Code/AllyCenter.h

@@ -0,0 +1,36 @@
+#ifndef __ALLYCENTER_H__
+#define __ALLYCENTER_H__
+
+#include "common.h"
+#include <vector>
+
+// 前向声明
+class Observer;
+class Player;
+
+// 抽象目标：联盟中心
+class AllyCenter
+{
+public:
+	AllyCenter();
+	// 声明通知方法
+	virtual void notify(INFO_TYPE infoType, std::string name) = 0;
+	// 加入玩家
+	void join(Observer* player);
+	// 移除玩家
+	void remove(Observer* player);
+protected:
+	// 玩家列表
+	std::vector<Observer*>playerList;
+};
+
+// 具体目标
+class AllyCenterController :public AllyCenter
+{
+public:
+	AllyCenterController();
+	// 实现通知方法
+	void notify(INFO_TYPE infoType, std::string name);
+};
+
+#endif //__ALLYCENTER_H__

20.ObserverPattern/2.Code/Demo.h

@@ -0,0 +1,67 @@
+#define __DEMO_H__
+#ifdef __DEMO_H__
+
+using namespace std;
+#include <list>
+
+// 抽象观察者
+class Observer
+{
+public:
+	// 声明响应更新方法
+	virtual void update() = 0;
+};
+
+// 具体观察者
+class ConcreteObserver:public Observer
+{
+public:
+	// 实现响应更新方法
+	void update(){
+		// 具体操作
+	}
+};
+
+// 抽象目标
+class Subject
+{
+public:
+	// 添加观察者
+	void attach(Observer* obs){
+		obsList.push_back(obs);
+	}
+	// 移除观察者
+	void detach(Observer* obs){
+		obsList.remove(obs);
+	}
+	// 声明通知方法
+	virtual void notify() = 0;
+protected:
+	// 观察者列表
+	list<Observer*>obsList;
+};
+
+// 具体目标
+class ConcreteSubject :public Subject
+{
+public:
+	// 实现通知方法
+	void notify(){
+		// 具体操作
+		// 遍历通知观察者对象
+		for (int i = 0; i < obsList.size(); i++){
+			obsList[i]->update();
+		}
+	}
+};
+
+// 客户端代码示例
+int main()
+{
+	Subject  *sub = new ConcreteSubject();
+	Observer *obs = new ConcreteObserver();
+	sub->attach(obs);
+	sub->notify();
+	return 0;
+}
+#endif

20.ObserverPattern/2.Code/Observer.h

@@ -0,0 +1,59 @@
+#ifndef __OBSERVER_H__
+#define __OBSERVER_H__
+
+#include <iostream>
+using namespace std;
+#include "common.h"
+#include "AllyCenter.h"
+
+// 抽象观察者 Observer
+class Observer
+{
+public:
+	Observer(){}
+	// 声明抽象方法
+	virtual void call(INFO_TYPE infoType, AllyCenter* ac) = 0;
+	string getName(){
+		return name;
+	}
+	void setName(string iName){
+		this->name = iName;
+	}
+private:
+	string name;
+};
+
+// 具体观察者 
+class Player :public Observer
+{
+public:
+	Player(){
+		setName("none");
+	}
+	Player(string iName){
+		setName(iName);
+	}
+	// 实现
+	void call(INFO_TYPE infoType, AllyCenter* ac){
+		switch (infoType){
+		case RESOURCE:
+			printf("%s :我这里有物资\n", getName().c_str());
+			break;
+		case HELP:
+			printf("%s :救救我\n", getName().c_str());
+			break;
+		default:
+			printf("Nothing\n");
+		}
+		ac->notify(infoType, getName());
+	}
+	// 实现具体方法
+	void help(){
+		printf("%s:坚持住，我来救你！\n", getName().c_str());
+	}
+	void come(){
+		printf("%s:好的，我来取物资\n", getName().c_str());
+	}
+};
+
+#endif

20.ObserverPattern/2.Code/common.h

@@ -0,0 +1,10 @@
+#ifndef __COMMON_H__
+#define __COMMON_H__
+
+enum INFO_TYPE{
+	NONE,
+	RESOURCE,
+	HELP
+};
+
+#endif //__COMMON_H__

20.ObserverPattern/2.Code/main.cpp

@@ -0,0 +1,32 @@
+#include "Observer.h"
+#include "AllyCenter.h"
+
+int main()
+{
+	// 创建一个战队
+	AllyCenterController* controller = new AllyCenterController();
+
+	// 创建4个玩家，并加入战队
+	Player* Jungle = new Player("Jungle");
+	Player* Single = new Player("Single");
+	Player* Jianmengtu = new Player("贱萌兔");
+	Player* SillyDog = new Player("傻子狗");
+	controller->join(Jungle);
+	controller->join(Single);
+	controller->join(Jianmengtu);
+	controller->join(SillyDog);
+
+	printf("\n\n");
+
+	// Jungle发现物资，呼叫队友
+	Jungle->call(RESOURCE, controller);
+
+	printf("\n\n");
+
+	// 傻子狗遇到危险，求救队友
+	SillyDog->call(HELP, controller);
+
+	printf("\n\n");
+	system("pause");
+	return 0;
+}

README.md

@@ -89,4 +89,8 @@ Jungle设计模式系列
 
 22.设计模式（二十二）——备忘录模式
 
-博客地址：https://blog.csdn.net/sinat_21107433/article/details/102907007
+博客地址：https://blog.csdn.net/sinat_21107433/article/details/102907007
+
+23.设计模式（二十三）——观察者模式
+
+博客地址：https://blog.csdn.net/sinat_21107433/article/details/102927937