单个 UIView 上的多个同时 UIViewAnimations

Question

目标：
在单个 UIView 上同时播放多个动画。
问题：
据我所知，这是不可能的。每个动画必须按顺序出现，不能重叠。

本质上，我想要一个 UIView 垂直动画，同时水平动画。由于我使用的是 UIViewAnimationOptionRepeat，因此我无法在 onCompletion 中嵌套任何其他动画：这是我想要工作但没有做到的：

[UIView animateWithDuration:duration
                      delay:kANIMATION_DELAY
                    options:UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse animations:^{

                        object.frame = CGRectMake(object.frame.origin.x + 40,
                                           object.frame.origin.y,
                                           object.frame.size.width,
                                           object.frame.size.height);

        [UIView animateWithDuration:duration
                              delay:kANIMATION_DELAY
                            options:UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse animations:^{

                                object.frame = CGRectMake(object.frame.origin.x,
                                                   object.frame.origin.y - 40,
                                                   object.frame.size.width,
                                                   object.frame.size.height);

                             } completion:^(BOOL finished) {
        }];

                    } completion:^(BOOL finished) {
}];

Answer 1

答案不是使用 UIViewAnimation 块，而是使用 CABasicAnimations。使用它们，您可以分别操纵中心坐标 (x,y)。这是我的代码现在的样子：

    UIView *view = views[i];

    // Add the horizontal animation
    CABasicAnimation *horizontal = [CABasicAnimation animationWithKeyPath:@"position.x"];

    horizontal.delegate = self;
    horizontal.fromValue = [NSNumber numberWithFloat:25.0];
    horizontal.toValue = [NSNumber numberWithFloat:50.0];
    horizontal.repeatCount = INFINITY;
    horizontal.duration = 6;
    horizontal.autoreverses = YES;
    horizontal.beginTime = 0; // ignore delay time for now
    horizontal.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    [view.layer addAnimation:horizontal forKey:@"horizontal_animation"];

    // Add the vertical animation
    CABasicAnimation *vertical = [CABasicAnimation animationWithKeyPath:@"position.y"];

    vertical.delegate = self;
    vertical.fromValue = [NSNumber numberWithFloat:100.0];
    vertical.toValue = [NSNumber numberWithFloat:400.0];
    vertical.repeatCount = INFINITY;
    vertical.duration = 2;
    vertical.autoreverses = YES;
    vertical.beginTime = 0; // ignore delay time for now
    vertical.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];

    [view.layer addAnimation:vertical forKey:@"vertical_animation"];

这允许我在两个单独的动画中处理重复、持续时间等。然后，当我的动画结束时，我可以调用 follow 方法来删​​除动画。要么，

    [view.layer removeAllAnimations];

或者，如果我想删除更具体的动画，

    [view.layer removeAnimationForKey:@"vertical_animation"];

然后，如果您想对动画开始/停止的时间进行更多自定义控制，您只需要像这样添加委托方法：

    -(void)animationDidStart:(CAAnimation *)anim {
        // custom code here
    }

    -(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
        // custom code here
    }

它非常甜蜜和容易。希望这可以帮助任何有类似需求的人。干杯！