Cocos2dx 提供的观察者模式工具类 CCNotificationCenter

Cocos2dx 提供的观察者模式工具类 CCNotificationCenter


1.addObserver(订阅消息)
2。removeObserver(取消订阅消息)
3.postNotification(发布消息)




同一资源文件的使用
.h:
//发布text消息
void sendMsg(CCObject *pSender);
//接收text消息的回调
void textMsg(CCObject *pSender);


.cpp:


bool HelloWorld::init()
{


    if ( !Layer::init() )
    {
        return false;
    }
    MenuItemImage*closeBtn = MenuItemImage::create("CloseSelected.png", "CloseNormal.png",this , 


menu_selector(HelloWorld::sendMsg));
closeBtn->setPosition(Vec2(visibleSize.width*0.1 , visibleSize.height*0.8));
Menu*menu = Menu::create(closeBtn , NULL);
menu->setPosition(Point(0,0));
addChild(menu);


//订阅消息类型为text的消息，不传递数据
CCNotificationCenter::sharedNotificationCenter()->addObserver(this, callfuncO_selector


(MyHelloWorldScene::textMsg) ,"text" , NULL);
return true;
}
void HelloWorld::sendMsg( CCObject *pSender )
{
CCString*sData = CCString::create("HellWorld");
sData->retain();
CCNotificationCenter::sharedNotificationCenter()->postNotification("text" , sData);
}


void HelloWorld::textMsg( CCObject *pSender )
{
log("订阅成功");
}


不同资源文件夹的使用
HelloWorld.h:
//发布text消息
void sendMsg(CCObject *pSender);


HelloWorld.cpp:
Scene* HelloWorld::createScene()
{
  
    auto scene = Scene::create();
    auto layer = HelloWorld::create();
    MyHelloWorldScene *OtherLayer  =MyHelloWorldScene::create();  //接受消息层
    scene->addChild(layer);
    scene->addChild(OtherLayer);
    return scene;
}
bool HelloWorld::init(){
//发送消息
    MenuItemImage*closeBtn = MenuItemImage::create("CloseSelected.png", "CloseNormal.png",this , 


menu_selector(HelloWorld::sendMsg));
closeBtn->setPosition(Vec2(visibleSize.width*0.1 , visibleSize.height*0.8));
Menu*menu = Menu::create(closeBtn , NULL);
menu->setPosition(Point(0,0));
addChild(menu);
}
void HelloWorld::sendMsg( CCObject *pSender )
{
CCString*sData = CCString::create("HellWorld");
sData->retain();
CCNotificationCenter::sharedNotificationCenter()->postNotification("text" , sData);
}


MyHelloWorldScene.h:
//接收text消息的回调
void textMsg(CCObject *pSender);
MyHelloWorldScene.cpp:
bool MyHelloWorldScene::init() {
if (!Layer::init()) {
return false;
}
size = Director::getInstance()->getVisibleSize();


//订阅消息类型为text的消息，不传递数据
CCNotificationCenter::sharedNotificationCenter()->addObserver(this, callfuncO_selector


(MyHelloWorldScene::textMsg) ,"text" , NULL);
return true;
}
void MyHelloWorldScene::textMsg( CCObject *pSender )
{
CCString*pData = (CCString*)pSender;
log("%s" , pData->getCString());
}