C++ 实现简单观察者模式

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<span style="font-family: Arial, Helvetica, sans-serif;"></span><pre name="code" class="cpp">//头文件/* *观察者模式---C++实现 *    By-Metoor */#ifndef _NotifyUtil_H_#define _NotifyUtil_H_#include <vector>#include <map>#include <functional>#include <string>class NotifyUtil {public:static NotifyUtil* getInstance();//订阅消息  <!--注意，订阅后在释放对象时一定要取消订阅-->void addObserver(const std::string &objectName, const std::string &messageName, std::function<void(void*)> func);//发布消息void postNotification(const std::string &messageName);void postNotification(const std::string &messageName, void* data);//取消订阅void removeObserve(const std::string &objectName, const std::string &messageName);private:NotifyUtil();private:static NotifyUtil* m_notifyUtil;std::map<std::string, std::map<std::string, std::function<void(void*)> > > m_funcMap;};#endif

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<span style="font-family: Arial, Helvetica, sans-serif;">//cpp文件</span>

#include "NotifyUtil.h"using namespace std;NotifyUtil* NotifyUtil::m_notifyUtil = NULL;NotifyUtil::NotifyUtil(){}NotifyUtil* NotifyUtil::getInstance(){if (m_notifyUtil == NULL){m_notifyUtil = new NotifyUtil();} return m_notifyUtil;}void NotifyUtil::addObserver(const std::string &objectName, const std::string &messageName, std::function<void(void*)> func){if (m_funcMap.find(messageName) != m_funcMap.end()){//如果消息已有人订阅map<string, function<void(void*)> > &funcMap = m_funcMap.at(messageName);funcMap.insert(pair<string, function<void(void*)> >(objectName, func));}else{//消息第一次被订阅map<string, function<void(void*)> > funcMap;funcMap.insert(pair<string, function<void(void*)> >(objectName, func));m_funcMap.insert(pair<string, map<string, function<void(void*)> > >(messageName, funcMap));}}void NotifyUtil::postNotification(const std::string &messageName){if (m_funcMap.find(messageName) != m_funcMap.end()){map<string, function<void(void*)> > &funcMap = m_funcMap.at(messageName);//遍历订阅了该消息的对象，调用其回调函数for(auto iter = funcMap.begin(); iter != funcMap.end(); ++iter){iter->second(nullptr);}}}void NotifyUtil::postNotification(const std::string &messageName, void* data){if (m_funcMap.find(messageName) != m_funcMap.end()){map<string, function<void(void*)> > &funcMap = m_funcMap.at(messageName);//遍历订阅了该消息的对象，调用其回调函数for(auto iter = funcMap.begin(); iter != funcMap.end(); ++iter){iter->second(data);}}}void NotifyUtil::removeObserve(const std::string &objectName, const std::string &messageName){map<string, function<void(void*)> > &funcMap = m_funcMap.at(messageName);funcMap.erase(funcMap.find(objectName));}

<pre name="code" class="cpp">//测试文件#include "NotifyUtil.h"#include <iostream>using namespace std;int main(){NotifyUtil::getInstance()->addObserver("589", "test2", [](void* v){ if(v == nullptr){cout << "---589---我接受的来自 test2 的消息...." <<endl; }else{cout << "---589---我接受的来自 test2 的消息....  data:" << (char*)v <<endl; }});NotifyUtil::getInstance()->addObserver("899","test2", [](void* v){ if(v == nullptr){cout << "---899---我接受的来自 test2 的消息...." <<endl; }else{cout << "---899---我接受的来自 test2 的消息....  data:" << (char*)v <<endl; }});NotifyUtil::getInstance()->removeObserve("589", "test2");NotifyUtil::getInstance()->postNotification("test2");NotifyUtil::getInstance()->postNotification("test2", (void*)"123456");return 0;}

</pre><img src="http://img.blog.csdn.net/20151014120427209?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="测试截图" /><img src="http://img.blog.csdn.net/20151014120257236?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="测试截图" /><pre>

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