五毛的cocos2d-x学习笔记05-场景与场景动画，动作

场景切换函数：

• Director->getInstance()->replaceScene(Scene*);
• Director->getInstance()->runWithScene(Scene*);

两者的区别在于，如果有Scene存在，使用第一个；第一次运行场景，用第二个。

下面是一个切换场景的关键代码。单击文本跳转到下一个场景。要切换到的场景ImageScene继承自Layer，定义了3个成员函数init，createScene，CREATE_FUNC。

ImageScene.h如下：

#ifndef _IMAGESCENE_H_
#define _IMAGESCENE_H_

#include<iostream>
#include<cocos2d.h>
USING_NS_CC;

class ImageScene :public Layer{
public:
    virtual bool init();
    static Scene* createScene();
    CREATE_FUNC(ImageScene);
};
#endif

ImageScene.cpp如下：

#include"ImageScene.h"

Scene* ImageScene::createScene(){
    Scene *scene = Scene::create();
    ImageScene *layer = ImageScene::create();
    scene->addChild(layer);

    return scene;
}
bool ImageScene::init(){
    if (!Layer::init()){
        return false;
    }

    Size size = Director::getInstance()->getVisibleSize();

    Sprite *s = Sprite::create("HelloWorld.png");
    s->setPosition(size.width/2, size.height/2);
    addChild(s);

    return true;
}

关键代码：

bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Point origin = Director::getInstance()->getVisibleOrigin();

    LabelTTF *label = LabelTTF::create("Show Next Scene", "Courier", 36);
    addChild(label);

    label->setPosition(visibleSize.width/2, visibleSize.height/2);

    EventListenerTouchOneByOne *listener = EventListenerTouchOneByOne::create();

    listener->onTouchBegan = [label](Touch *t, Event *e){
        if (label->getBoundingBox().containsPoint(t->getLocation())){
            Director::getInstance()->replaceScene(ImageScene::createScene());
            return true;
        }
        return false;
    };
    Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, label);
    return true;
}

运行效果：

场景切换效果能让场景的切换不显得突兀。场景切换效果主要是TransitionScene的子类实现的。

修改关键代码的第21行 

Director::getInstance()->replaceScene(TransitionFade::create(3.0f, ImageScene::createScene()));

切换效果：

Action动作

类的主要继承关系图

关键代码：

• label->runAction(MoveTo::create(1.0f, Point(100, 100)));
• label->runAction(MoveTo::create(1.0f, Point(-100, -100))->reverse());//MoveTo::reserve()在cocos2d-x3.5之后被屏蔽了，因为没有意义
• label->runAction(MoveBy::create(1.0f, Point(-10, -10)));
• label->runAction(MoveBy::create(1.0f, Point(10, 10))->reverse());//效果和上面一句相同，reverse是反转执行。

效果是不同的，运行效果：

详细代码如下：

bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }
    
    Size visibleSize = Director::getInstance()->getVisibleSize();
    
    LabelTTF *label = LabelTTF::create("Hello, Cocos", "Courier", 30);
    label->setPosition(visibleSize.width / 2, visibleSize.height / 2);
    addChild(label);
    
    EventListenerTouchOneByOne *listener = EventListenerTouchOneByOne::create();
    listener->onTouchBegan = [label](Touch* t,Event* e){
        if (label->getBoundingBox().containsPoint(t->getLocation())){
            label->runAction(MoveTo::create(1.0f, Point(100, 100)));
            //label->runAction(MoveBy::create(1.0f, Point(-10,-10)));
        }
        return false;
    };
    Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, label);
    return true;
}

Repeat/RepeatForever：

//在1秒内完成180度旋转，重复3次。

label->runAction(Repeat::create(RotateBy::create(1.0f, 180), 3));

//在1秒内完成180度旋转，一直重复。
label->runAction(RepeatForever::create(RotateBy::create(1.0f, 180)));

运行结果：

动作混合：Spawn类

//label会一边移动一边旋转

//在末尾写一个NULL，标识数组的结束。
label->runAction(Spawn::create(MoveBy::create(1, Point(100, 100)), RotateBy::create(1, 360), NULL));

运行效果：

动作序列：Sequence类

//label先移动，然后再旋转

//在末尾写一个NULL， 标识数组的结束

label->runAction(Sequence::create(MoveBy::create(1, Point(100, 100), RotateBy::create(1, 360)), NULL));

运行效果：

动作的监听：

CallFunc类继承自FiniteTimeAction，所以可以用这个类来实现监听效果。

//label先移动，然后再旋转，旋转结束之后，弹出一个弹框。

label->runAction(Sequence::create(
                MoveBy::create(1, Point(100, 100)), 
                RotateBy::create(1, 360), 
                CallFunc::create([](){
                MessageBox("Action Complete", "Complete");
            }), NULL));

运行结果：

附上本节所有源码：

bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }
    
    Size visibleSize = Director::getInstance()->getVisibleSize();
    
    LabelTTF *label = LabelTTF::create("Hello, Cocos", "Courier", 30);
    label->setPosition(visibleSize.width / 2, visibleSize.height / 2);
    addChild(label);
    
    EventListenerTouchOneByOne *listener = EventListenerTouchOneByOne::create();
    listener->onTouchBegan = [label](Touch* t,Event* e){
        if (label->getBoundingBox().containsPoint(t->getLocation())){
            //label->runAction(MoveTo::create(1.0f, Point(100, 100)));
            //label->runAction(MoveBy::create(1.0f, Point(-10,-10)));
            //label->runAction(MoveBy::create(1.0f, Point(10, 10))->reverse());//效果和上面一句相同
            //label->runAction(Repeat::create(RotateBy::create(1.0f, 180), 3));
            //label->runAction(RepeatForever::create(RotateBy::create(1.0f, 180)));
            //在末尾写一个NULL，标识数组的结束。
            //label->runAction(Spawn::create(MoveBy::create(1, Point(100, 100)), RotateBy::create(1, 360), NULL));
            //label->runAction(Sequence::create(MoveBy::create(1, Point(100, 100)), RotateBy::create(1, 360), NULL));
            label->runAction(Sequence::create(
                MoveBy::create(1, Point(100, 100)), 
                RotateBy::create(1, 360), 
                CallFunc::create([](){
                MessageBox("Action Complete", "Complete");
            }), NULL));

        }
        return false;
    };
    Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, label);
    return true;
}