我希望我的下落精灵在屏幕的一半消失

Question

我是编程新手，我一直在用 cocos2d 做实验，问题出在这里，我做了一个简单的游戏，设备是纵向的，它有掉落的精灵，我希望精灵在顶部的位置消失sprite

这里有一些你可能感兴趣的代码：

这是下落的精灵，它从屏幕顶部落到底部

-(void)addRock {

CCSprite *rock = [CCSprite spriteWithFile:@"rock.png" 
                                     rect:CGRectMake(0, 0, 27, 40)]; 

// Determine where to spawn the target along the X axis
CGSize winSize = [[CCDirector sharedDirector] winSize];
int minX = rock.contentSize.width/2;
int maxX = winSize.width - rock.contentSize.width/2;
int rangeX = maxX - minX;
int actualX = (arc4random() % rangeX) + minX;

// Create the target slightly off-screen along the right edge,
// and along a random position along the X axis as calculated above
rock.position = ccp(actualX, 500);
[self addChild:rock];

// Determine speed of the target
int actualDuration = spriteDuration;//speed of sprite

// Create the actions
id actionMove = [CCMoveTo actionWithDuration:actualDuration position:ccp(actualX,-winSize.height+ rock.contentSize.height)];
id actionMoveDone = [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)];
[rock runAction:[CCSequence actions:actionMove, nil]];

}

当精灵移动完成时

-(void)spriteMoveFinished:(id)sender {
CCSprite *sprite = (CCSprite *)sender;
[self removeChild:sprite cleanup:YES];

}

Answer 1

要在动画的中途淡出你的精灵，你可以使用 CCSpawn 将 falling 动画与 fadeOut 结合起来。但是由于您希望它在给定时间后淡出，您需要创建一个由CCDelayTime 和CCFadeOut 组成的序列。

double fadeStart = 0.5;
id wait    = [CCDelayTime actionWithDuration: actualDuration * fadeStart];
id fadeOut = [CCFadeOut actionWithDuration: actualDuration * (1.0 - fadeStart)];
id waitThenFade = [CCSequence actions: wait, fadeOut, nil];

id actionMove = ...;
id fullAnimation = [CCSpawn actions:actionMove, waitThenFade, nil];

[rock runAction:[CCSequence actions:fullAnimation, actionMoveDone, nil]];

如果您希望早点或晚点开始淡入淡出，您只需移动 fadeStart 值。 0 会立即开始，1 实际上不会褪色，所以最好在两者之间选择一个值。

Answer 2

也许是这样的？

CGSize size = [[CCDirector sharedDirector] winSize];

CCSprite* img = [[CCSprite alloc] initWithFile:@"yourSprite.png"];
img.position = ccp(size.width/2,size.height + img.boundingBox.size.height/2);
[img runAction:[CCSequence actions:
                    [CCMoveTo actionWithDuration:3 position:ccp(img.position.x,size.height/2 - img.boundingBox.size.height/2)],
                    [CCFadeOut actionWithDuration:1],
                    [CCCallFuncN actionWithTarget:nil selector:@selector(spriteMoveFinished:)],
                    nil]];