2

我试图在一个循环内重复一系列动画，在每个循环中随机改变一些参数。这是代码。请问有人知道为什么它不起作用吗？如果我用按钮操作调用它一次，它可以工作，但循环它不会。非常感谢！朱塞佩

-(IBAction)startLoop:(id)sender {
    for (int i=1;i<10; i++) {
        [self animation2];
    }
}


-(id) animation2 {

    int max=500;
    UIImage *myImage = [UIImage imageNamed:@"coccinella2.png"];
    CALayer *myLayer = [CALayer layer];
    myLayer.contents = (id)myImage.CGImage;
    myLayer.bounds = CGRectMake(0, 0, 50, 60);
    [myLayer setPosition:CGPointMake(arc4random()%(max), arc4random()%(max))];
    [myLayer setBounds:CGRectMake(0.0, 0.0, 50.0, 60.0)];
    [self.view.layer addSublayer:myLayer];


    //translation1
    CGPoint startPt = CGPointMake(arc4random()%(max),arc4random()%(max));
    CGPoint endPt = CGPointMake(arc4random()%(max),arc4random()%(max));
    CABasicAnimation *transl1 = [CABasicAnimation animationWithKeyPath:@"position"];
    transl1.removedOnCompletion = FALSE;
    transl1.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
    transl1.fromValue = [NSValue valueWithCGPoint:startPt];
    transl1.toValue = [NSValue valueWithCGPoint:endPt];
    transl1.duration = 2.0;
    transl1.fillMode = kCAFillModeForwards;
    transl1.beginTime = 0;

    //scale 1
    CABasicAnimation *scale1 = [CABasicAnimation 
                                animationWithKeyPath:@"transform.scale"];
    scale1.removedOnCompletion = FALSE;
    [scale1 setToValue:[NSNumber numberWithInt:3]];
    [scale1 setDuration:2.0f];
    scale1.fillMode = kCAFillModeForwards;
    scale1.beginTime = 0;

    //rotation1
    CABasicAnimation *rotation1 = [CABasicAnimation 
                                   animationWithKeyPath:@"transform.rotation.z"];
    rotation1.removedOnCompletion = FALSE;
    [rotation1 setFromValue:DegreesToNumber(0)];
    [rotation1 setToValue:DegreesToNumber(90)];
    //rotation1.repeatCount = HUGE_VALF;
    [rotation1 setDuration:2.0f];
    rotation1.fillMode = kCAFillModeForwards;
    rotation1.beginTime = 0;

    //group
    CAAnimationGroup* group = [CAAnimationGroup animation];
    [group setDuration: 6.0];
    group.removedOnCompletion = FALSE;
    group.fillMode = kCAFillModeForwards;
    [group setAnimations: [NSArray arrayWithObjects:scale1, transl1, rotation1, nil]];
    [myLayer addAnimation: group forKey:  nil];
}
4

2 回答 2

2

您的代码不会重复注释 10 次，而是立即启动 10 个动画。如果您的目标是在前一个动画结束后开始动画，您应该尝试使用NSTimer.

于 2012-05-07T09:59:50.833 回答
1

您可以使用 NSTimer 在不同的时间触发每组动画，也可以在每组上设置 beginTime，代码如下：

group.beginTime = CACurrentMediaTime() + delay;

对于动画，使用 beginTime 可以提供更准确的计时，因为 CA 在单独的线程上运行，并且不会像 NSTimers 那样在您的应用程序繁忙时停止。

于 2012-05-08T00:10:24.520 回答