iOS动画（Core Animation）

Core Animation（核心动画）简介

• 它是一组非常强大的动画处理API，使用它能做出非常炫丽的动画效果。
• Core Animation的动画执行过程都是在后台操作的，不会阻塞主线程。
• Core Animation是直接作用在CALayer上的，并非UIView。

CAAnimation是所有动画类的父类，但是它不能直接使用，应该使用它的子类。

• CAPropertyAnimation是CAAnimation的子类，但是不能直接使用，要想创建动画对象，应该使用它的两个子类：CABasicAnimation和CAKeyframeAnimation
• 能用的动画类只有4个子类：CABasicAnimation、CAKeyframeAnimation、CATransition、CAAnimationGroup

平移动画

示例代码

@interface ViewController () 

@property (nonatomic, weak) CALayer *layer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    CALayer *layer = [CALayer layer];
    layer.bounds = CGRectMake(0, 0, 50, 50);
    layer.position = CGPointMake(50, 50);
    // 设置layer的锚点为左上角（0，0）
    layer.anchorPoint = CGPointMake(0, 0);
    layer.backgroundColor = [UIColor redColor].CGColor;
    layer.cornerRadius = 10;
    
    [self.view.layer addSublayer:layer];
    self.layer = layer;
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 创建核心动画
    CABasicAnimation *anim = [CABasicAnimation animation];
    
    // 要执行什么样的动画
    anim.keyPath = @"position";
    
    // 通过动画，将layer从哪儿移动到哪儿
    anim.fromValue = [NSValue valueWithCGPoint:CGPointMake(0, 0)];
    anim.toValue  = [NSValue valueWithCGPoint:CGPointMake(200, 300)];
    
    // 完成动画所需要消耗的时间
    anim.duration  = 2;
    
    // 动画执行完毕之后不删除动画
    anim.removedOnCompletion = NO;
    // 保存动画的最新状态
    anim.fillMode = kCAFillModeForwards;
    
    // 设置动画的代理，可以监听动画的执行过程，这里设置控制器为代理
    anim.delegate = self;
    
    //添加核心动画到layer
    [self.layer addAnimation:anim forKey:nil];
}

- (void)animationDidStart:(CAAnimation *)anim {
    NSLog(@"执行前: %@", NSStringFromCGPoint(self.layer.position));
}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
    NSLog(@"执行后: %@", NSStringFromCGPoint(self.layer.position));
}

验证图层的属性值还是动画执行前的初始值{50，50}，并没有真正被改变

• 实质上，图层的属性值还是动画执行前的初始值，并没有真正被改变

position.png

缩放动画

代码示例:

@interface ViewController () 

@property (nonatomic, weak) CALayer *layer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    CALayer *layer = [CALayer layer];
    layer.bounds = CGRectMake(0, 0, 50, 50);
    layer.position = CGPointMake(50, 50);
    // 设置layer的锚点为左上角（0，0）
    layer.anchorPoint = CGPointMake(0, 0);
    layer.backgroundColor = [UIColor redColor].CGColor;
    layer.cornerRadius = 10;
    
    [self.view.layer addSublayer:layer];
    self.layer = layer;
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 创建核心动画
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"bounds"];
    
    // 设置动画执行时间
    anim.duration  = 2;
    
    // 动画执行完毕之后不删除动画
    anim.removedOnCompletion = NO;
    // 保存动画的最新状态
    anim.fillMode = kCAFillModeForwards;
    
    // 修改属性，执行动画
    anim.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, 200, 200)];
    //添加核心动画到layer
    [self.layer addAnimation:anim forKey:nil];
}

旋转动画

示例代码:

@interface ViewController () 

@property (nonatomic, weak) CALayer *layer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    CALayer *layer = [CALayer layer];
    layer.bounds = CGRectMake(0, 0, 150, 50);
    layer.position = CGPointMake(50, 50);
    // 设置layer的锚点为左上角（0，0）
    layer.anchorPoint = CGPointMake(0, 0);
    layer.backgroundColor = [UIColor redColor].CGColor;
    layer.cornerRadius = 10;
    
    [self.view.layer addSublayer:layer];
    self.layer = layer;
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
     // 创建动画
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform"];
    // 设置动画执行时间
    anim.duration  = 2;
  // 修改属性，执行动画
    anim.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI_4, 1, 1, 0)];
    // 动画执行完毕之后不删除动画
    anim.removedOnCompletion = NO;
    // 保存动画的最新状态
    anim.fillMode = kCAFillModeForwards;
    [self.layer addAnimation:anim forKey:nil]; 
}

关键帧动画简介

是CApropertyAnimation的子类，跟CABasicAnimation的区别是：CABasicAnimation只能从一个数值(fromValue)变到另一个数值(toValue)，而CAKeyframeAnimation会使用一个NSArray保存这些数值
示例代码:

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *customerView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 创建动画
    CAKeyframeAnimation *keyAnim = [CAKeyframeAnimation animation];
    // 要执行什么样的动画
    keyAnim.keyPath = @"position";
    NSValue *value1=[NSValue valueWithCGPoint:CGPointMake(100, 100)];
    NSValue *value2=[NSValue valueWithCGPoint:CGPointMake(200, 100)];
    NSValue *value3=[NSValue valueWithCGPoint:CGPointMake(200, 200)];
    NSValue *value4=[NSValue valueWithCGPoint:CGPointMake(100, 200)];
    NSValue *value5=[NSValue valueWithCGPoint:CGPointMake(100, 100)];
    keyAnim.values=@[value1,value2,value3,value4,value5];
    
    // 动画执行完毕之后不删除动画
    keyAnim.removedOnCompletion = NO;
    // 保存动画的最新状态
    keyAnim.fillMode = kCAFillModeForwards;
     // 设置动画执行时间
    keyAnim.duration = 3.0;
    // 设置代理
    keyAnim.delegate = self;
    // 设置动画的节奏
    keyAnim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    //添加核心动画到layer
    [self.customerView.layer addAnimation:keyAnim forKey:nil];
}

- (void)animationDidStart:(CAAnimation *)anim {
    NSLog(@"开始动画");
}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
    NSLog(@"结束动画");
}

停止动画（可以通过path属性，让layer在指定的轨迹上运动）

代码示例如下

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *customerView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 创建动画
    CAKeyframeAnimation *keyAnim = [CAKeyframeAnimation animation];
    // 平移
    keyAnim.keyPath = @"position";
    // 创建一条路径
    CGMutablePathRef path = CGPathCreateMutable();
    // 设置一个圆的路径
    CGPathAddEllipseInRect(path, NULL, CGRectMake(150, 100, 100, 100));
    keyAnim.path = path;
    
    //有create就一定要有release
    CGPathRelease(path);
    
    // 动画执行完毕之后不删除动画
    keyAnim.removedOnCompletion = NO;
    // 保存动画的最新状态
    keyAnim.fillMode = kCAFillModeForwards;
    // 设置动画执行时间
    keyAnim.duration = 3.0;
    
    // 设置动画的节奏
    keyAnim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    //添加核心动画到layer
    [self.customerView.layer addAnimation:keyAnim forKey:@"next"];

}

- (IBAction)stop {
    // 停止self.customView.layer上名称标示为nextone的动画
    [self.customerView.layer removeAnimationForKey:@"next"];
}

图标抖动

#define angle2Radian(angle) ((angle)/180.0*M_PI)

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIImageView *iconImageView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 创建动画
    CAKeyframeAnimation *keyAnim = [CAKeyframeAnimation animation];
    // 要执行什么样的动画
    keyAnim.keyPath = @"transform.rotation";
    // 设置动画时间
    keyAnim.duration = 0.1;
    // 设置图片抖动弧度
    // 把度数转换为弧度（度数/180*M_PI）
    keyAnim.values = @[@(-angle2Radian(6)), @(angle2Radian(6)), @(-angle2Radian(6))];
    // 设置动画的重复次数
    keyAnim.repeatCount = MAXFLOAT;
    // 动画执行完毕之后不删除动画
    keyAnim.removedOnCompletion = NO;
    // 保存动画的最新状态
    keyAnim.fillMode = kCAFillModeForwards;
    [self.iconImageView.layer addAnimation:keyAnim forKey:nil];

}

转场动画和组动画

• CATransition(转场动画)是CAAnimation的子类，能够为层提供移出屏幕和移入屏幕的动画效果
• UINavigationController就是通过CATransition实现了将控制器的视图推入屏幕的动画效果

属性解析:
type：动画过渡类型
subtype：动画过渡方向
startProgress：动画起点(在整体动画的百分比)
endProgress：动画终点(在整体动画的百分比)

代码示例

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (nonatomic, assign) NSInteger index;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    self.index = 1;
}


- (IBAction)preClick:(id)sender {
    self.index--;
    if (self.index < 1) {
        self.index = 3;
    }
    self.imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"Guide%ld", self.index]];
    // 创建核心动画
    CATransition *anim = [CATransition animation];
    //设置过度效果
    anim.type = @"cube";
    //设置动画的过度方向（向左
    anim.subtype = kCATransitionFromLeft;
    anim.duration = 2.0;
    [self.imageView.layer addAnimation:anim forKey:nil];
}

- (IBAction)nextClick:(id)sender {
    self.index++;
    if (self.index > 3) {
        self.index = 1;
    }
    self.imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"Guide%ld", self.index]];
    // 创建核心动画
    CATransition *anim = [CATransition animation];
    //设置过度效果
    anim.type = @"cube";
    //设置动画的过度方向（向左
    anim.subtype = kCATransitionFromRight;
    anim.duration = 2.0;
    // 设置动画的起点
    anim.startProgress = 0.5;
    [self.imageView.layer addAnimation:anim forKey:nil];
}

动画组(平移-旋转-缩放作为一组动画一起执行)

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *iconView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 平移动画
    CABasicAnimation *a1 = [CABasicAnimation animation];
    a1.keyPath = @"transform.translation.y";
    a1.toValue = @(300);
    
    // 缩放动画
    CABasicAnimation *a2 = [CABasicAnimation animation];
    a2.keyPath = @"transform.scale";
    a2.toValue = @(0.0);
    
    // 旋转动画
    CABasicAnimation *a3 = [CABasicAnimation animation];
    a3.keyPath = @"transform.rotation";
    a3.toValue = @(M_PI_2);
    
    // 组动画
    CAAnimationGroup *groupAnim = [CAAnimationGroup animation];
    groupAnim.animations  = @[a1, a2, a3];
    
    groupAnim.duration = 3;
    groupAnim.fillMode = kCAFillModeForwards;
    groupAnim.removedOnCompletion = NO;
    
    [self.iconView.layer addAnimation:groupAnim forKey:nil];
}

UIView封装动画

• UIKit直接将动画集成到UIView类中，当内部的一些属性发生改变时，UIView将为这些改变提供动画支持

代码示例

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *customerView;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 首尾式动画
   [UIView beginAnimations:nil context:nil];
    //执行动画
    //设置动画执行时间
    [UIView setAnimationDuration:2.0];
    self.customerView.center=CGPointMake(200, 300);
    //设置代理
    [UIView setAnimationDelegate:self];
    //设置动画执行完毕调用的事件
    [UIView setAnimationDidStopSelector:@selector(didStopAnimation)];
}

- (void)didStopAnimation {
    NSLog(@"动画执行完毕");
}

注：UIView封装的动画执行完毕之后不会反弹。即如果是通过CALayer核心动画改变layer的位置状态，表面上看虽然已经改变了，但是实际上它的位置是没有改变的

block动画

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *customerView;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    /*
     duration：动画的持续时间
     delay：动画延迟delay秒后开始
     options：动画的节奏控制
     animations：将改变视图属性的代码放在这个block中
     completion：动画结束后，会自动调用这个block
     */
    [UIView animateWithDuration:2.0
                          delay:3.0
                        options:UIViewAnimationOptionBeginFromCurrentState
                     animations:^{
                         self.customerView.center=CGPointMake(200, 300);
                     }
                     completion:^(BOOL finished) {
                         NSLog(@"动画执行完毕");
                     }];
    
    
}

转场动画

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIView *customerView;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [UIView transitionWithView:self.customerView
                      duration:3.0
                       options:0
                    animations:^{
                        self.customerView.center=CGPointMake(200, 300);
                    } completion:^(BOOL finished) {
                        NSLog(@"动画执行完毕");
                    }];
}

UIImageView的帧动画

UIImageView可以让一系列的图片在特定的时间内按顺序显示

@interface ViewController ()

@property (nonatomic, strong) NSMutableArray *images;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@end

@implementation ViewController

- (NSMutableArray *)images {
    if (!_images) {
        _images = [NSMutableArray array];
        for (int i = 0; i < 4; i++) {
            UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.jpg", i]];
            [_images addObject:image];
        }
    }
    return _images;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    _imageView.userInteractionEnabled = YES;
    _imageView.animationImages = self.images;
    _imageView.animationDuration = 1.0;
    _imageView.animationRepeatCount = 0;
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    if (![_imageView isAnimating]) {
        [_imageView startAnimating];
    } else {
        [_imageView stopAnimating];
    }
}

相关链接:
Core Animation、核心动画