如何在 Objective C 中为浮动 UIView 设置动画

Question

我正在尝试将UIView 动画化为浮动对象或气球：D UIView 在屏幕中间，我希望它在第一个启动点周围随机浮动。不跨越屏幕或类似的东西，只是漂浮在它周围 5 个像素的区域内。

有什么建议吗？ :D

我试过这个：

[UIView animateWithDuration:0.1
                      delay:0.0
                    options: UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse | UIViewAnimationOptionAllowUserInteraction
                 animations:^{
                     myCircleUIView.transform = CGAffineTransformMakeTranslation([self randomFloatingGenerator], [self randomFloatingGenerator]);
                 }
                 completion:NULL];

randomFloatingGenerator 生成一个介于 -5 和 5 之间的数字。问题是，它只执行一次，并且不断重复使用相同的随机值。

EDIT1： 现在我已经尝试过了

-(void)animationLoop{

[UIView animateWithDuration:1.0
                     animations: ^{ myCircleUIView.transform = CGAffineTransformMakeTranslation([self randomFloatingGenerator], [self randomFloatingGenerator]); }
                     completion:
     ^(BOOL finished) {
         [UIView animateWithDuration:1.0
                          animations:^{ myCircleUIView.transform = CGAffineTransformMakeTranslation(0,0);
                          }
                          completion:
          ^(BOOL finished) {[self animationLoop];}];
     }];

但它仍然无法正常工作，动画......糟糕......我想我正在犯一些愚蠢的错误，我需要第二双眼睛来帮助我。

EDIT2： 修好了。

 -(void)animationLoop{
    CGPoint oldPoint = CGPointMake(myCircleUIView.frame.origin.x, myCircleUIView.frame.origin.y);
    [UIView animateWithDuration:1.0
                     animations: ^{ myCircleUIView.frame = CGRectMake(myCircleUIView.frame.origin.x + [self randomFloatingGenerator], myCircleUIView.frame.origin.y + [self randomFloatingGenerator], myCircleUIView.frame.size.width, myCircleUIView.frame.size.height); }
                     completion:
     ^(BOOL finished) {
         [UIView animateWithDuration:1.0
                          animations:^{ myCircleUIView.frame = CGRectMake(oldPoint.x, oldPoint.y, myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);}
                          completion:
          ^(BOOL finished) {[self animationLoop];}];
     }];
}

感谢任何人的帮助。

编辑 3：

有人发布了增强的代码。

Answer 1

@Shamy 的解决方案，经过改进、修复和 CPU 安全。

-(void)animateFloatView:(UIView*)view{

    // Abort the recursive loop
    if (!view)
        return;

    CGPoint oldPoint = CGPointMake(view.frame.origin.x, view.frame.origin.y);
    [UIView animateWithDuration:0.6
                     animations: ^{ view.frame = CGRectMake(view.frame.origin.x, view.frame.origin.y - 15, view.frame.size.width, view.frame.size.height); }
                     completion:
     ^(BOOL finished) {

         if (finished) {
             [UIView animateWithDuration:0.6
                              animations:^{ view.frame = CGRectMake(oldPoint.x, oldPoint.y, view.frame.size.width, view.frame.size.height);}
                              completion:
              ^(BOOL finished2) {
                  if(finished2)
                      [self animateFloatView:view];
              }];

         }
     }];
}

当你想停止动画时（离开 View Controller 时需要），使用 nil 调用函数，如下所示：

    [self recursiveFloatingAnimation:nil];

不停止动画会导致递归循环无限运行，压垮CPU栈。

Answer 2

斯威夫特 4

UIView.animate(withDuration: 0.6, delay: 0.1, options: [.autoreverse, .repeat], animations: {
    self.frame = CGRect(x: self.frame.origin.x, y: self.frame.origin.y - 15, width: self.frame.size.width, height: self.frame.size.height)
},completion: nil )

Answer 3

它将以这种方式运行。当您重复动画而不是功能时。因此，每次您在第一次调用时设置时，它都会重复相同的动画。这样做：

@interface AAViewController ()

@property (nonatomic, strong) UIView * floatingView;
@end

@implementation AAViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    _floatingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
    [_floatingView setBackgroundColor:[UIColor redColor]];
    [self.view addSubview:_floatingView];

    [self circleUIViewFloating];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Circle UIView floating

- (void) circleUIViewFloating {

    [UIView animateWithDuration:2.0
                     animations:^{
                         _floatingView.transform = CGAffineTransformMakeTranslation([self randomFloatingGenerator : 270], [self randomFloatingGenerator:480]);
                     } completion:^(BOOL finished) {
                         [self circleUIViewFloating];
                     }];
}

- (int) randomFloatingGenerator : (int) max{
    return arc4random() % max;
}

这里是complete running project。

Answer 4

您可以使用CABasicAnimation 实现悬停或浮动效果。

您必须包含QuartzCore 框架才能使用它。

Swift 4.2：

import QuartzCore

let hover = CABasicAnimation(keyPath: "position")
    hover.isAdditive = true
    hover.fromValue = NSValue(cgPoint: CGPoint.zero)
    hover.toValue = NSValue(cgPoint: CGPoint(x: 0.0, y: -5.0))
    hover.autoreverses = true
    hover.duration = 0.8
    hover.repeatCount = Float.infinity
    myCustomView.layer.add(hover, forKey: "hoverAnimation")

确保在不再显示视图时移除动画。

    override func viewWillDisappear(_ animated: Bool) {
        // Stop animating when view is going to disappear
        myCustomView.layer.removeAllAnimations()
    }

Answer 5

-(void)animationLoop{
CGPoint oldPoint = CGPointMake(myCircleUIView.frame.origin.x, myCircleUIView.frame.origin.y);
[UIView animateWithDuration:1.0
                 animations: ^{ myCircleUIView.frame = CGRectMake(myCircleUIView.frame.origin.x + [self randomFloatingGenerator], myCircleUIView.frame.origin.y + [self randomFloatingGenerator], myCircleUIView.frame.size.width, myCircleUIView.frame.size.height); }
                 completion:
 ^(BOOL finished) {
     [UIView animateWithDuration:1.0
                      animations:^{ myCircleUIView.frame = CGRectMake(oldPoint.x, oldPoint.y, myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);}
                      completion:
      ^(BOOL finished) {[self animationLoop];}];
 }];
}

Answer 6

Swift 2.1 版本在这里：

func animateFloatView(view: UIView?) {
    // Abort the recursive loop
    guard let view = view else { return }


    let oldPoint: CGPoint = CGPointMake(view.frame.origin.x, view.frame.origin.y)
    UIView.animateWithDuration(0.6, animations: {() -> Void in
        view.frame = CGRectMake(view.frame.origin.x, view.frame.origin.y - 15, view.frame.size.width, view.frame.size.height)
        }, completion: {(finished: Bool) -> Void in
            if finished {
                UIView.animateWithDuration(0.6, animations: {() -> Void in
                    view.frame = CGRectMake(oldPoint.x, oldPoint.y, view.frame.size.width, view.frame.size.height)
                    }, completion: {(finished2: Bool) -> Void in
                        if finished2 {
                            self.animateFloatView(view)
                        }
                })
            }
    })
}

Answer 7

Swift 3.1：

func animateFloatView(_ view: UIView?) {
    guard let view = view else { return }
    let oldYCoordinate = view.center.y

    UIView.animate(withDuration: 0.6, animations: {
        view.center.y -= 15
    }, completion: { _ in
        UIView.animate(withDuration: 0.6, animations: {
            view.center.y = oldYCoordinate
        }, completion: { _ in
            self.animateFloatView(view)
        })
    })
}