Cocos2d-x学习（二）：动作Action（延时类动作）

游戏中的大部分精灵都是动态的，所以动作类是游戏引擎中不可或缺的一部分，今天就简单的记录下Cocos2d-x中常用的动作类。

Cocos2d-x提供了很多基本的动作类，主要包括两大类：一类是瞬时动作（CCActionInstant），一类是延时动作（CCActionInterval），今天主要记录一下延时动作类的一般用法。

1.Cocos2d-x提供的基本延时类动作都提供了ActionTo和ActionBy两种：（Action泛指各种动作）

ActionTo是指动作结束的状态，也就是动作的终点。

ActionBy是指动作执行的状态，也就是动作的执行过程。

常用的延时动作类包括：

移动动作：CCMoveBy CCMoveTo

旋转动作：CCRotateBy CCRotateTo

缩放动作：CCScaleBy CCScaleTo

跳跃动作：CCJumpBy CCJumpTo

淡入淡出动作：CCFadeBy CCFadeIn CCFadeOut

贝赛尔曲线动作：CCBezierBy CCBezierTo

......（还有很多种，就不一一列举了，详情查看）

2.一般用法

动作中最简单的就要数移动了，下面就分别以CCMoveBy和CCMoveTo举个例子，代码很简单

[cpp]
void HelloWorld::spriteMove()
{
    CCSize winSize = CCDirector::sharedDirector()->getWinSize();

    CCActionInterval *actionTo = CCMoveTo::actionWithDuration(2.0f,
        CCPointMake(winSize.width * 3 / 4, winSize.height / 2));
    CCActionInterval *actionBy = CCMoveBy::actionWithDuration(2.0f,
        CCPointMake(-winSize.width / 2, 0));
    CCActionInterval *actionByCopy = (CCActionInterval *) actionBy->copy();
    CCActionInterval *actionBack = actionBy->reverse();

    oldManSprite->runAction(CCSequence::actions(actionTo, actionByCopy, NULL));
    youngSisterSprite->runAction(CCSequence::actions(actionBy, actionBack, NULL));
}
void HelloWorld::spriteMove()
{
CCSize winSize = CCDirector::sharedDirector()->getWinSize();

CCActionInterval *actionTo = CCMoveTo::actionWithDuration(2.0f,
CCPointMake(winSize.width * 3 / 4, winSize.height / 2));
CCActionInterval *actionBy = CCMoveBy::actionWithDuration(2.0f,
CCPointMake(-winSize.width / 2, 0));
CCActionInterval *actionByCopy = (CCActionInterval *) actionBy->copy();
CCActionInterval *actionBack = actionBy->reverse();

oldManSprite->runAction(CCSequence::actions(actionTo, actionByCopy, NULL));
youngSisterSprite->runAction(CCSequence::actions(actionBy, actionBack, NULL));
}

用法很简单，CCMoveTo中的CCPoint参数就是想要“移动到”的位置点，而CCMoveBy中的CCPoint参数就是分别对应x，y轴对应的偏移量 www.zzzyk.com

（这里是对cocos2d-x中的test示例做了一些修改）

这里需要注意的是actionBy不能重复使用，如果第二次使用的话，会继续从第一次使用到的位置开始继续，不明白的可以尝试一下，现象很明显！

3.动作完成回调

动作一般支持3种回调方式

(1).无发送者无数据回调：CCCallFunc，示例如下

[cpp]
void HelloWorld::actionCallback()
{
    CCSize winSize = CCDirector::sharedDirector()->getWinSize();

    CCLabelTTF *label = CCLabelTTF::labelWithString("Action Callback!", "Marker Felt", 32);
    label->setPosition(ccp(winSize.width / 2, winSize.height / 2));

    this->addChild(label);
}
void HelloWorld::actionCallback()
{
CCSize winSize = CCDirector::sharedDirector()->getWinSize();

CCLabelTTF *label = CCLabelTTF::labelWithString("Action Callback!", "Marker Felt", 32);
label->setPosition(ccp(winSize.width / 2, winSize.height / 2));

this->addChild(label);
}

(2).有发送者无数据回调：CCCallFuncN (N是CCNode)，示例如下

[cpp]
void HelloWorld::actionCallbackN(CCNode *pSender)
{
    CCSprite *sprite = (CCSprite *) pSender;

    // 回调变红色
    sprite->setColor(ccRED);
}
void HelloWorld::actionCallbackN(CCNode *pSender)
{
CCSprite *sprite = (CCSprite *) pSender;

// 回调变红色
sprite->setColor(ccRED);
}

(3).有发送者有数据回调：CCCallFuncND (N是CCNode，D是data，是void *类型)

[cpp]
void HelloWorld::actionCallbackND(CCNode *pSender, void *data)
{
    CCSize winSize = CCDirector::sharedDirector()->getWinSize();

    CCSprite *sprite = (CCSprite *) pSender;

    // 回调变蓝色
    sprite->setColor(ccBLUE);

    // 接收回调数据
    CCLabelTTF *label = CCLabelTTF::labelWithString((char *) data, "Marker Felt", 32);
    label->setPosition(ccp(winSize.width / 2, winSize.height / 2));
    this->addChild(label);

    CCLog((char *) data);
}
void HelloWorld::actionCallbackND(CCNode *pSender, void *data)
{
CCSize winSize = CCDirector::sharedDirector()->getWinSize();

CCSprite *sprite = (CCSprite *) pSender;

// 回调变蓝色
sprite->setColor(ccBLUE);

// 接收回调数据
CCLabelTTF *label = CCLabelTTF::labelWithString((char *) data, "Marker Felt", 32);
label->setPosition(ccp(winSize.width / 2, winSize.height / 2));
this->addChild(label);

CCLog((char *) data);
}
使用回调示例如下：

[cpp]
void HelloWorld::actionListen()
{
    CCSize winSize = CCDirector::sharedDirector()->getWinSize();

    CCFiniteTimeAction *action = CCSequence::actions(
        CCMoveBy::actionWithDuration(2.0f, CCPointMake(winSize.width / 2, 0)),
        CCCallFunc::actionWithTarget(this, callfunc_selector(HelloWorld::actionCallback)), NULL);

    CCFiniteTimeAction *actionN = CCSequence::actions(
        CCMoveBy::actionWithDuration(2.0f, CCPointMake(-winSize.width / 2, 0)),
        CCCallFuncN::actionWithTarget(this, callfuncN_selector(HelloWorld::actionCallbackN)), NULL);

    CCFiniteTimeAction *actionND = CCSequence::actions(
        CCMoveBy::actionWithDuration(2.0f, CCPointMake(winSize.width / 2, 0)),
        CCCallFuncND::actionWithTarget(this, callfuncND_selector(HelloWorld::actionCallbackND), (void *) "Callback Data"), NULL);

    oldManSprite->runAction(actionND);
    youngSisterSprite->runAction(actionN);
}
void HelloWorld::actionListen()
{
CCSize winSize = CCDirector::sharedDirector()->getWinSize();

补充：移动开发 , 其他 ,