iOS 动画 —— 活动加载器

平常我们在加载数据的时候通常用UIActivityIndicatorView, 但是有时产品想改改样式，在此刚好看到几款动画兴许可以当做活动加载器，特此学习下。

学习来源：DTIActivityIndicatorView-Swift，在此用Objective-C模仿一下。

一、圈圈的跳动

pulse

#import "PulseView.h"

@interface PulseView ()

@property (nonatomic, strong) UIView *pulseView;

@end

@implementation PulseView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        
        CGSize pulseSize = CGRectInset(frame, 2.0, 2.0).size;
        _pulseView = [[UIView alloc] init];
        _pulseView.backgroundColor = [UIColor whiteColor];
        _pulseView.frame = CGRectMake(0.0, 0.0, pulseSize.width, pulseSize.height);
        _pulseView.layer.cornerRadius  = MIN(pulseSize.width,pulseSize.height)/2.0;
        [self addSubview:_pulseView];
        
    }
    return self;
}

- (void)startAnimating {
    
    CAKeyframeAnimation *scaleAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
    scaleAnimation.values = @[@0,@1];
    
    CAKeyframeAnimation *opacityAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"opacity"];
    opacityAnimation.values = @[@1,@0];
    
    CAAnimationGroup *group = [CAAnimationGroup animation];
    group.duration = 1.0;
    group.repeatCount = MAXFLOAT;
    group.removedOnCompletion = NO;
    group.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    group.animations = @[scaleAnimation, opacityAnimation];
    [self.pulseView.layer addAnimation:group forKey:@"Animation_Pulse"];
    
}

@end

二、变换的跳动

doublw

#import "DoubleBounceView.h"

@interface DoubleBounceView ()

@property (nonatomic, strong) UIView *bounceOutView;
@property (nonatomic, strong) UIView *bounceInView;

@end

@implementation DoubleBounceView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        
        CGSize size = CGRectInset(frame, 2.0, 2.0).size;
        _bounceInView = [self makeBounceViewWithSize:size];
        _bounceOutView = [self makeBounceViewWithSize:size];
        [self addSubview:_bounceOutView];
        [self addSubview:_bounceInView];
    }
    return self;
}

- (UIView *)makeBounceViewWithSize:(CGSize)size {
    UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(0, 0, size.width, size.height);
    view.backgroundColor = [UIColor whiteColor];
    view.layer.cornerRadius = MIN(size.width,size.height)/2.0;
    view.layer.opacity = 0.6;
    return view;
}

- (void)startAnimating {
    
    CAKeyframeAnimation *scaleInAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
    scaleInAnimation.values = @[@0, @1, @0];
    scaleInAnimation.removedOnCompletion = NO;
    scaleInAnimation.repeatCount = CGFLOAT_MAX;
    scaleInAnimation.duration = 2;
    scaleInAnimation.timingFunctions = @[
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                  ];

    
    CAKeyframeAnimation *scaleOutAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
    scaleOutAnimation.values = @[@1, @0, @1];
    scaleOutAnimation.removedOnCompletion = NO;
    scaleOutAnimation.repeatCount = MAXFLOAT;
    scaleOutAnimation.duration = 2;
    scaleOutAnimation.timingFunctions = @[
                                         [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                         [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                         [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
           
                                         ];
    [self.bounceOutView.layer addAnimation:scaleOutAnimation forKey:@"scaleOutAnimation"];
    [self.bounceInView.layer addAnimation:scaleInAnimation forKey:@"scaleInAnimation"];
 
}


@end

三、琴块的变化

wave.gif

#import "WaveView.h"

static const NSInteger kRectCount = 5;
static const CGFloat kSpaceBetweenRect = 3.0;

@interface WaveView ()

@property (nonatomic, strong) UIView *rectView;

@end

@implementation WaveView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
    
        _rectView = [[UIView alloc] initWithFrame: frame];
        [self addSubview:_rectView];
        
        CGFloat rectWidth = (frame.size.width - kSpaceBetweenRect *(kRectCount-1)) / kRectCount;
        for (NSInteger i = 0; i < kRectCount; ++i) {
            CALayer *layer = [CALayer layer];
            layer.transform =  CATransform3DMakeScale(1.0, 0.4, 0.0);
            layer.backgroundColor = [UIColor whiteColor].CGColor;
            layer.frame = CGRectMake(i * (rectWidth + kSpaceBetweenRect), 0, rectWidth, frame.size.height);
            [_rectView.layer addSublayer:layer];
        }
        
    }
    return self;
}

- (void)startAnimating {
    
    for (NSInteger i = 0; i < kRectCount; ++i) {
        
        CALayer *layer = self.rectView.layer.sublayers[i];
        
        CAKeyframeAnimation *animation =  [CAKeyframeAnimation animationWithKeyPath:@"transform"];
        animation.removedOnCompletion = NO;
        animation.repeatCount = MAXFLOAT;
        animation.duration = 1.2;
        
        animation.beginTime = CACurrentMediaTime() + i * 0.1;
        animation.keyTimes = @[@0.0,@0.2, @0.4,@1.0];
        animation.timingFunctions = @[
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                      ];
        animation.values = @[
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 0.4, 0.0)],
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 1.0, 0.0)],
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 0.4, 0.0)],
                             [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 0.4, 0.0)]
                             ];
    
        [layer addAnimation:animation forKey:[NSString stringWithFormat:@"wave_animation_%lu",i]];
        
    }
   
}

@end

四、方块的旋转

Rota.gif

#import "RotatingView.h"

@interface RotatingView ()

@property (nonatomic, strong) UIView *planeView;

@end

@implementation RotatingView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
 
        CGSize size = CGRectInset(frame, 2.0, 2.0).size;
        _planeView = [[UIView alloc] init];
        _planeView.backgroundColor = [UIColor whiteColor];
        _planeView.frame = CGRectMake(0.0, 0.0, size.width, size.height);
        [self addSubview:_planeView];
    }
    return self;
}


CATransform3D transformPlane(CGFloat perspective, CGFloat angle,
                             CGFloat x, CGFloat y, CGFloat z) {
    CATransform3D translation = CATransform3DIdentity;
    translation.m34 = perspective;
    return CATransform3DRotate(translation, angle, x, y, z);
    
}

- (void)startAnimating {
    
    CAKeyframeAnimation *animation =  [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    animation.removedOnCompletion = NO;
    animation.repeatCount = MAXFLOAT;
    animation.duration = 2;
    animation.keyTimes = @[@0.0,@0.45,@0.95];
    animation.timingFunctions = @[
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                  [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                  ];
    animation.values = @[
                         [NSValue valueWithCATransform3D:transformPlane(1.0/120.0, 0.0, 0.0, 0.0, 0.0)],
                          [NSValue valueWithCATransform3D:transformPlane(1.0/120.0, (CGFloat)M_PI, 0.0, 1.0, 0.0)],
                          [NSValue valueWithCATransform3D:transformPlane(1.0/120.0, (CGFloat)M_PI, 0.0, 0.0, 1.0)]
                         ];
  
    [self.planeView.layer addAnimation:animation forKey:@"Animation_Plane"];
}

@end

五、二圆旋转飞

Chasing.gif

#import "ChasingView.h"

@interface ChasingView ()

@property (nonatomic, strong) UIView *dotOneView;
@property (nonatomic, strong) UIView *dotTwoView;

@end

@implementation ChasingView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        
        self.layer.shouldRasterize = YES;
        self.backgroundColor = [UIColor lightGrayColor];
        CGFloat sizeWidth = frame.size.width * 3/5;
        _dotOneView = [self makeDotViewWithSize:CGRectMake((frame.size.width - sizeWidth)/2.0, 1.0, sizeWidth, sizeWidth)];
        _dotTwoView = [self makeDotViewWithSize:CGRectMake((frame.size.width - sizeWidth)/2.0, frame.size.height = sizeWidth, sizeWidth, sizeWidth)];
        [self addSubview:_dotOneView];
        [self addSubview:_dotTwoView];
        
    }
    return self;
}

- (UIView *)makeDotViewWithSize:(CGRect)rect {
    UIView *view = [[UIView alloc] init];
    view.frame = rect;
    view.backgroundColor = [UIColor whiteColor];
    view.layer.cornerRadius = MIN(rect.size.width,rect.size.height)/2.0;
    return view;
}

- (void)startAnimating {
    
    CABasicAnimation *ratotionAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    ratotionAnimation.fromValue = @0;
    ratotionAnimation.toValue = @(2 * M_PI);
    ratotionAnimation.removedOnCompletion = NO;
    ratotionAnimation.repeatCount = MAXFLOAT;
    ratotionAnimation.duration = 2.0;
    ratotionAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
    [self.layer addAnimation:ratotionAnimation forKey:@"chasing_rotation"];
    
    
    CAKeyframeAnimation *scaleOneAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
    scaleOneAnimation.values = @[@1, @0, @1];
    scaleOneAnimation.removedOnCompletion = NO;
    scaleOneAnimation.repeatCount = CGFLOAT_MAX;
    scaleOneAnimation.duration = 2;
    scaleOneAnimation.timingFunctions = @[
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                          
                                          ];
    
    CAKeyframeAnimation *scaleTwoAnimation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
    scaleTwoAnimation.values = @[@0, @1, @0];
    scaleTwoAnimation.removedOnCompletion = NO;
    scaleTwoAnimation.repeatCount = CGFLOAT_MAX;
    scaleTwoAnimation.duration = 2;
    scaleTwoAnimation.timingFunctions = @[
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                          [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                          
                                          ];
    [self.dotOneView.layer addAnimation:scaleOneAnimation forKey:@"chasing_one_scale"];
    [self.dotTwoView.layer addAnimation:scaleTwoAnimation forKey:@"chasing_two_scale"];
    
}

@end

六、三个点

threePoint.gif

#import "SpotifyView.h"

static const NSInteger kCircleCount = 3;

@interface SpotifyView ()

@property (nonatomic, strong) UIView *circleView;

@end

@implementation SpotifyView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        
        _circleView = [[UIView alloc] initWithFrame: frame];
        [self addSubview:_circleView];
        
        CGFloat circleWidth = frame.size.width / (kCircleCount*2 + 1);
        CGFloat posY = (frame.size.height - circleWidth)/2;
        for (NSInteger i = 0; i < kCircleCount; ++i) {
            CALayer *layer = [CALayer layer];
            layer.backgroundColor = [UIColor whiteColor].CGColor;
            layer.cornerRadius = circleWidth/2;
            layer.frame = CGRectMake(circleWidth + i*(circleWidth*2), posY, circleWidth, circleWidth);
            [_circleView.layer addSublayer:layer];
        }
        
    }
    return self;
}

- (void)startAnimating {
    
    for (NSInteger i = 0; i < kCircleCount; ++i) {
        
        CALayer *layer = self.circleView.layer.sublayers[i];

        CAKeyframeAnimation *animation =  [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
        animation.removedOnCompletion = NO;
        animation.repeatCount = MAXFLOAT;
        animation.duration = 1.2;
        animation.values = @[@1.0, @1.7, @1.0, @1.0];
        animation.beginTime = CACurrentMediaTime() + i * 0.2;
        animation.keyTimes = @[@0.0,@0.2, @0.4,@1.0];
        animation.timingFunctions = @[
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut],
                                      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]
                                      ];
        
        [layer addAnimation:animation forKey:[NSString stringWithFormat:@"spotify_animation_%lu",i]];
        
    }
    
}

@end

七、网易刷新圈圈（额外需要图片的）

网易刷新圈圈

#import "ShowView.h"

static const CGFloat kCicleEdge  = 7.0f;

@interface ShowView ()

@property (nonatomic, strong) CALayer *ballLayer;
@property (nonatomic, strong) CALayer *circleLayer;

@end

@implementation ShowView

- (instancetype)initWithFrame:(CGRect)frame {
    if ([super initWithFrame:frame]) {
        
        UIImage *ballImage = [UIImage imageNamed:@"ball"]; // size == 30 * 30
        UIImage *circleImage =  [UIImage imageNamed:@"circle"]; // size == 100 * 30
        
        _ballLayer = [CALayer layer];
        _ballLayer.frame = CGRectMake(0, 0, ballImage.size.width - kCicleEdge, ballImage.size.height - kCicleEdge);
        _ballLayer.position = CGPointMake(self.center.x, _ballLayer.position.y);
        _ballLayer.contents = (id)ballImage.CGImage;
        
        _circleLayer = [CALayer layer];
        _circleLayer.frame = CGRectMake(0, 0, circleImage.size.width, circleImage.size.height);
        _circleLayer.position = CGPointMake(self.center.x, _ballLayer.position.y - kCicleEdge);
        _circleLayer.contents = (id)circleImage.CGImage;

        [self.layer addSublayer:_ballLayer];
        [self.layer insertSublayer:_circleLayer below:_ballLayer];
    }
    return self;
}

// 增加动画
- (void) startAnimating  {
    // 变大
    CABasicAnimation *enlarge = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
    enlarge.duration = 0.5f;
    enlarge.repeatCount = 1.0f;
    enlarge.removedOnCompletion = NO;
    enlarge.fromValue = @(0.5f);
    enlarge.toValue = @(1.0f);
    
    // 变小
    CABasicAnimation *decrease = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
    decrease.duration = 0.5f;
    decrease.repeatCount = 1.0f;
    decrease.removedOnCompletion = NO;
    decrease.beginTime = 0.5f;
    decrease.fromValue = @(1.0f);
    decrease.toValue = @(0.5f);
    
    // 位置
    CABasicAnimation *position = [CABasicAnimation animationWithKeyPath:@"position"];
    position.duration = 1.0f;
    position.repeatCount = MAXFLOAT;
    position.fromValue =[NSValue valueWithCGPoint:self.circleLayer.position];
    position.toValue = [NSValue valueWithCGPoint:CGPointMake(self.circleLayer.position.x, self.circleLayer.position.y + self.circleLayer.frame.size.height)];
    
    // 将三组动画组合成
    CAAnimationGroup *group = [CAAnimationGroup animation];
    group.duration = 1;
    group.repeatCount = MAXFLOAT;
    group.removedOnCompletion = NO;
    group.autoreverses = YES;
    group.animations = @[enlarge, decrease, position];
    [self.circleLayer addAnimation:group forKey:@"Animation"];
}

// 移除动画
- (void)removeAnimation {
     [self.circleLayer removeAnimationForKey:@"Animation"];
}

@end

PS：上述尝试实现，都是直接用 frame 的！用自动布局尝试直接修改里面的chu

重点是看startAnimating 中的实现！

PS： 另外同时学习 Swift ，直接去看 DTIActivityIndicatorView-Swift 里面的实现是很有必要，虽说好久没更新啦。

同时通过上面几组的学习尝试，更加了体会到了一般动画的构成。

• CALayer === > Who 事件是谁做 ；
• CAAnimation ===> How 事件怎么做；
• AddAnimation ===> Add 将谁做和做怎么结合起来。

虽说上述几组动画都是一些基本的简单动画，但是任何复杂的动画都是由简单动画构成，所以再次提醒自己动画并没有想象中那么难！