如何移动一个cocos2d-x精灵

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void addTarget()函数将会帮我们完成这一工作，敌人将会以随机的速度，从游戏场景左移动到右。

在HelloWorldScence.h里声明void addTarget()，并在HelloWorldScene.cpp里添加以下的代码，(请不要忘记在HelloWorldScene.cpp的开头加入using namespace cocos2d)

1// cpp with cocos2d-x

2void HelloWorld::addTarget()

3{

4 CCSprite *target = CCSprite::spriteWithFile("Target.png",

5 CCRectMake(0,0,27,40) );

6

7 // Determine where to spawn the target along the Y axis

8 CCSize winSize = CCDirector::sharedDirector()->getWinSize();

9 int minY = target->getContentSize().height/2;

10 int maxY = winSize.height

11 - target->getContentSize().height/2;

12 int rangeY = maxY - minY;

13 // srand( TimGetTicks() );

14 int actualY = ( rand() % rangeY ) + minY;

15

16 // Create the target slightly off-screen along the right edge,

17 // and along a random position along the Y axis as calculated

18 target->setPosition(

19 ccp(winSize.width + (target->getContentSize().width/2),

20 actualY) );

21 this->addChild(target);

22

23 // Determine speed of the target

24 int minDuration = (int)2.0;

25 int maxDuration = (int)4.0;

26 int rangeDuration = maxDuration - minDuration;

27 // srand( TimGetTicks() );

28 int actualDuration = ( rand() % rangeDuration )

29 + minDuration;

30

31 // Create the actions

32 CCFiniteTimeAction* actionMove =

33 CCMoveTo::actionWithDuration( (ccTime)actualDuration,

34 ccp(0 - target->getContentSize().width/2, actualY) );

35 CCFiniteTimeAction* actionMoveDone =

36 CCCallFuncN::actionWithTarget( this,

37 callfuncN_selector(HelloWorld::spriteMoveFinished));

38 target->runAction( CCSequence::actions(actionMove,

39 actionMoveDone, NULL) );

40}

1// objc with cocos2d-iphone

2-(void)addTarget

3{

4 CCSprite *target = [CCSprite spriteWithFile"Target.png"

5 rect:CGRectMake(0, 0, 27, 40)];

6

7 // Determine where to spawn the target along the Y axis

8 CGSize winSize = [[CCDirector sharedDirector] winSize];

9 int minY = target.contentSize.height/2;

10 int maxY = winSize.height - target.contentSize.height/2;

11 int rangeY = maxY - minY;

12

13 int actualY = (arc4random() % rangeY) + minY;

14

15 // Create the target slightly off-screen along the right edge,

16 // and along a random position along the Y axis as calculated

17 target.position =

18 ccp(winSize.width + (target.contentSize.width/2),

19 actualY);

20 [self addChild:target];

21

22 // Determine speed of the target

23 int minDuration = 2.0;

24 int maxDuration = 4.0;

25 int rangeDuration = maxDuration - minDuration;

26

27 int actualDuration = (arc4random() % rangeDuration)

28 + minDuration;

29

30 // Create the actions

31 id actionMove =

32 [CCMoveTo actionWithDuration:actualDuration

33 position:ccp(-target.contentSize.width/2, actualY)];

34 id actionMoveDone =

35 [CCCallFuncN actionWithTarget:self

36 selectorselector(spriteMoveFinished];

37 [target runAction:[CCSequence actions:actionMove,

38 actionMoveDone, nil]];

39}

这里用callfuncN_selector(HelloWorld::spriteMoveFinished)回调了spriteMoveFinished方法，我们需要在HelloWorldScene.h里声明并如下来定义它，

1// cpp with cocos2d-x

2void HelloWorld::spriteMoveFinished(CCNode* sender)

3{

4 CCSprite *sprite = (CCSprite *)sender;

5 this->removeChild(sprite, true);

6}

1// objc with cocos2d-iphone

2-(void)spriteMoveFinishedid)sender

3{

4 CCSprite *sprite = (CCSprite *)sender;

5 [self removeChild:sprite cleanup:YES];

6}

要点

1. 关于随机函数。srand和rand是C标准库函数。对于每一个平台来说，你可以先获取毫秒级时间来得到一个随机数。在沃Phone上，这个函数是TimGetTickes()，而在iPhone上，你可以直接通过arc4random()函数来获得随机数。

2. Objc中的YES和NO，在cpp中变为true和false。

3. 回调函数，在objc中用selectorselector(spriteMoveFinished)，但在cpp中实现就比较复杂了，你可以参考cocos2dx\include\selector_protocol.h里的声明。一共有5种回调函数类型

 schedule_selector

 callfunc_selector

 callfuncN_selector

 callfuncND_selector

 menu_selector

如何使用它们，根据所用函数的定义来决定。比如使用CCTimer::initWithTarget函数，它的第二个参数是SEL_SCHEDULE类型，到selector_protocol.h里查一下，可以看到对应的是schedule_selector(_SELECTOR)宏，所以调用时就需要在类里头实现一个void MyClass::MyCallbackFuncName(ccTime)函数，然后把schedule_selector(MyClass::MyCallbackFuncName)作为CCTimer::initWithTarget的第二个参数传入。

之后，我们应该定时地为游戏加入敌人，把以下代码加入到init()函数的返回值前。

1// cpp with cocos2d-x

2// Call game logic about every second

3this->schedule( schedule_selector(HelloWorld::gameLogic), 1.0 );

1// objc with cocos2d-iphone

2// Call game logic about every second

3[self scheduleselector(gameLogic interval:1.0];

然后在HelloWorldScence.cpp里实现gameLogic()。请注意gameLogic()应该声明为pubilc，否则是无法回调的。

1// cpp with cocos2d-x

2void HelloWorld::gameLogic(ccTime dt)

3{

4 this->addTarget();

5}

1// objc with cocos2d-iphone

2-(void)gameLogicccTime)dt

3{

4 [self addTarget];

5}

好了，所有事情都做完了，编译并运行，好好享用你的成果。

iPhone

Android

沃Phone

Win32

﹋Winべ9べ

学习了不错，很好

spring

干休楼主分享

asdhasd

学到了，，楼主加油。