iOS之核心动画

1.将动画的所有方法封装到一个类里面

MyCAHelper.h
#import <Foundation/Foundation.h>
#import <QuartzCore/QuartzCore.h>

#define kCAHelperAlphaAnimation @"opacity"; // 淡入淡出动画
#define kCAHelperScaleAnimation @"transform.scale"; // 比例缩放动画
#define kCAHelperRotationAnimation @"transform.rotation"; // 旋转动画
#define kCAHelperPositionAnimation @"position"; // 平移位置动画

@interface MyCAHelper : NSObject

#pragma mark - 基本动画统一调用方法
+ (CABasicAnimation *)myBasicAnimationWithType:(NSString *)animationType
duration:(CFTimeInterval)duration
from:(NSValue *)from
to:(NSValue *)to
autoRevereses:(BOOL)autoRevereses;

#pragma mark - 关键帧动画方法
#pragma mark 摇晃动画
+ (CAKeyframeAnimation *)myKeyShakeAnimationWithDuration:(CFTimeInterval)duration
angle:(CGFloat)angle
repeatCount:(CGFloat)repeatCount;

#pragma mark 贝塞尔路径动画
+ (CAKeyframeAnimation *)myKeyPathAnimationWithDuration:(CFTimeInterval)duration
path:(UIBezierPath *)path;

#pragma mark 弹力仿真动画
+ (CAKeyframeAnimation *)myKeyBounceAnimationFrom:(CGPoint)from
to:(CGPoint)to
duration:(CFTimeInterval)duration;

@end
MyCAHelper.m
#import "MyCAHelper.h"

@implementation MyCAHelper

#pragma mark - 基本动画统一调用方法
+ (CABasicAnimation *)myBasicAnimationWithType:(NSString *)animationType
duration:(CFTimeInterval)duration
from:(NSValue *)from
to:(NSValue *)to
autoRevereses:(BOOL)autoRevereses
{
        // 1. 实例化一个CA动画对象
        CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:animationType];
        
        // 2. 设置动画属性
        [anim setDuration:duration];
        
        [anim setFromValue:from];
        [anim setToValue:to];
        
        [anim setAutoreverses:autoRevereses];
        
        return anim;
}

#pragma mark - 关键帧动画方法
#pragma mark 摇晃动画
+ (CAKeyframeAnimation *)myKeyShakeAnimationWithDuration:(CFTimeInterval)duration
angle:(CGFloat)angle
repeatCount:(CGFloat)repeatCount
{
        // 1. 初始化动画对象实例
        CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"transform.rotation"];
        
        // 2. 设置动画属性
        [anim setDuration:duration];
        
        [anim setValues:@[@(angle), @(-angle), @(angle)]];
        
        [anim setRepeatCount:repeatCount];
        
        return anim;
}

#pragma mark 贝塞尔路径动画
+ (CAKeyframeAnimation *)myKeyPathAnimationWithDuration:(CFTimeInterval)duration
path:(UIBezierPath *)path
{
        // 1. 初始化动画对象实例
        CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"position"];
        
        // 2. 设置动画属性
        [anim setDuration:duration];
        
        [anim setPath:path.CGPath];
        
        return anim;
}

#pragma mark 弹力仿真动画
+ (CAKeyframeAnimation *)myKeyBounceAnimationFrom:(CGPoint)from
to:(CGPoint)to
duration:(CFTimeInterval)duration
{
        // 是一个基于路径的动画
        // 首先定义一个路径，记录弹力仿真的整个路径
        CGMutablePathRef path = CGPathCreateMutable();
        
        // 弹力仿真路径创建代码
        // 计算起始点与目标点之间的位置偏移量，这个偏移量的目的是为了能够计算出小球第一次延伸的长度
        CGFloat offsetX = from.x - to.x;
        CGFloat offsetY = from.y - to.y;
        
        // 1. 移动到起始点
        CGPathMoveToPoint(path, NULL, from.x, from.y);
        // 2. 将目标点的坐标添加到路径之中
        CGPathAddLineToPoint(path, NULL, to.x, to.y);
        // 3. 设置小球的弹力因子
        CGFloat offsetDivider = 4.0f;
        
        while (YES) {
                // 加延伸方向的路径
                CGPathAddLineToPoint(path, NULL, to.x + offsetX / offsetDivider,
                to.y + offsetY / offsetDivider);
                
                // 再次将目标点添加到路径
                CGPathAddLineToPoint(path, NULL, to.x, to.y);
                
                // 弹力因子递增，保证越来越接近目标点
                offsetDivider += 6.0f;
                
                // 当小球的当前位置距离目标点足够小，我们退出循环
                if ((abs(offsetX / offsetDivider) < 10.0f)
                && (abs(offsetY / offsetDivider) < 10.0f)) {
                
                    break;
                }
        }

        CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"position"];
        [anim setPath:path];
        
        // 释放路径
        CGPathRelease(path);
        
        [anim setDuration:duration];
        
        return anim;
}

@end
#import "ViewController.h"
#import "MyCAHelper.h"

@interface ViewController ()
{
        UIView *_demoView;
        CGPoint location;
}
@end

@implementation ViewController

- (void)viewDidLoad
{
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        [self.view setBackgroundColor:[UIColor lightGrayColor]];
        
        _demoView = [[UIView alloc]initWithFrame:CGRectMake(50, 50, 100, 100)];
        [_demoView setBackgroundColor:[UIColor whiteColor]];
        [self.view addSubview:_demoView];
}

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

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
        UITouch *touch = [touches anyObject];
        location = [touch locationInView:self.view];
        
        // [_demoView setCenter:location];
        /** 
        1.测试基本动画
        */
        // CABasicAnimation *anim = [self testBasic1];
        // [anim setRepeatCount:3];
        // 
        // [_demoView.layer addAnimation:anim forKey:nil];
        /**
        2.测试弹力仿真动画效果
        */
        // [_demoView.layer addAnimation:[self test1:_demoView.center to:location] forKey:nil];
        /**
        3.测试路径关键帧动画
        */
        // [_demoView.layer addAnimation:[self test2] forKey:nil];
        // [_demoView.layer addAnimation:[self test4:_demoView.center to:location] forKey:nil];
        /**
        4.测试摇晃关键帧动画
        */
        // 点击屏幕，开始摇晃，再次点击，停止摇晃
        // CAAnimation *anim = [_demoView.layer animationForKey:@"shakeAnimation"];
        // if (anim) {
        // [_demoView.layer removeAnimationForKey:@"shakeAnimation"];
        // } else {
        // [_demoView.layer addAnimation:[self test5] forKey:@"shakeAnimation"];
        // }
        CAKeyframeAnimation *anim = [self test1:_demoView.center to:location];
        [_demoView.layer addAnimation:anim forKey:nil];
}
-(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
        // 需要在这里对不同对象的动画方法进行完成处理！
        [_demoView setCenter:location];
        NSLog(@"%@", NSStringFromCGPoint(_demoView.center));
}

#pragma mark - 重构方法测试
#pragma mark 测试贝塞尔路径关键帧动画
- (CAKeyframeAnimation *)test5
{
        return [MyCAHelper myKeyShakeAnimationWithDuration:0.2 angle:M_PI_4 / 18 repeatCount:MAXFLOAT];
}

#pragma mark 测试贝塞尔路径关键帧动画
- (CAKeyframeAnimation *)test4:(CGPoint)from to:(CGPoint)to
{
        UIBezierPath *path = [UIBezierPath bezierPath];
        
        // 有两个控制点去挤出的曲线，能挤出S型的曲线
        [path moveToPoint:from];
        [path addCurveToPoint:to controlPoint1:CGPointMake(320, 0) controlPoint2:CGPointMake(0, 460)];
        
        return [MyCAHelper myKeyPathAnimationWithDuration:2.0 path:path];
}

#pragma mark 测试贝塞尔路径关键帧动画
- (CAKeyframeAnimation *)test3:(CGPoint)from to:(CGPoint)to
{
        UIBezierPath *path = [UIBezierPath bezierPath];
        
        // 只有一个控制点去挤出的曲线
        [path moveToPoint:from];
        [path addQuadCurveToPoint:to controlPoint:CGPointMake(320, 230)];
        
        return [MyCAHelper myKeyPathAnimationWithDuration:2.0 path:path];
}

#pragma mark 测试路径关键帧动画
- (CAKeyframeAnimation *)test2
{
        UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 100, 100)];
        return [MyCAHelper myKeyPathAnimationWithDuration:2.0 path:path];
}

#pragma mark 测试弹力仿真动画效果
- (CAKeyframeAnimation *)test1:(CGPoint)from to:(CGPoint)to
{
        CAKeyframeAnimation *anim = [MyCAHelper myKeyBounceAnimationFrom:from to:to duration:1.5];
        [anim setFillMode:kCAFillModeForwards];
        [anim setRemovedOnCompletion:NO];
        
        [anim setDelegate:self];
        
        return anim;
}

- (CABasicAnimation *)testBasic1
{
        return [MyCAHelper myBasicAnimationWithType:@"opacity" duration:1.0 from:@(1.0) to:@(0.3) autoRevereses:YES];
}

@end

一、核心动画概念

－导入QuartzCore.framework框架

1⃣ 开发步骤
1.初始化一个动画对象（CAAnimation）并且设置一些动画相关属性

2.CALayer中很多属性都可以通过CAAnimation实现动画效果，包括：opacity、position、transform、bounds、contents等（可以在API文档中搜索：CALayer Animatable Properties）

3.添加动画对象到层（CALayer）中，开始执行动画

4.通过调用CALayer的addAnimation：forKey增加动画到层（CALayer）中，这样就能触发动画。通过调用removeAnimationForKey可以停止层中的动画

5.Core Animation的动画执行过程都是后台操作的，不会阻塞主线程

2⃣ 属性
1.duration：动画的持续时间

2.repeatCount：重复次数（HUGE_VALF、MAX FLOAT无限重复）

3.repeatDuration：重复时间（用的很少）

4.removedOnCompletion：默认为Yes。动画执行完后默认会从图层删除掉

5.fillMode
6.biginTime
7.timingFunction：速度控制函数，控制动画节奏

8.delegate

二、基础动画（CABasicAnimation）
如果只是实现简单属性变化的动画效果，可以使用UIView的块动画替代基本动画

1⃣ 属性说明
－fromValue：keyPath相应属性值的初始值

－toValue：keyPath相应属性的结束值

2⃣ 动画过程说明：

－随着动画的就行，在duration的持续时间内，keyPath相应的属性值从fromValue渐渐变为toValue

－keyPath内容是CALayer的可动画Animation属性

－如果fillMode＝kCAFillModeForwards同时removedOnCompletion＝NO，那么在动画执行完毕后，图层会保持显示动画执行后的状态，但在实质上，图层的属性值还是动画执行前的初始值，并没有真正改变

3⃣ 代码实现
位移需要考虑目标点设定的问题

三、关键帧动画（CAKeyframeAnimation）

基础动画只能从一个值到另一个值，关键帧动画可以用一个数组保存一系列值

1⃣ 属性说明
－values：所有的值（用的较少）

－path：路线（如果设置了path，那么values将被忽略）

－keyTimes：可以为对应的关键帧制定对应的时间点，取值范围是0到1.0

2⃣ 过程步骤
－初始化自定义视图

－点击屏幕，执行动画

1.指定点平移动画（values）

2.路径平移动画（path C语言框架CGMutablePathRef，需要手动释放内存）

3.贝塞尔路径动画（OC框架UIBezierPath）

4.摇晃动画（修改旋转角度）

3⃣ 代码重构
如上代码，重构在了一起

四、动画组
动画是可以并发执行的

－定义一个group组

－定义动画
－将动画加入group组

－可以给组设置属性

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
        UITouch *touch = [touches anyObject];
        CGPoint location = [touch locationInView:self.view];
        
        [_demoView setBackgroundColor:[UIColor redColor]];
        
        // 1. 定义动画组
        CAAnimationGroup *group = [CAAnimationGroup animation];
        // 定义一组动画
        // 淡入淡出动画
        CABasicAnimation *alpha = [MyCAHelper myBasicAnimationWithType:kCAHelperAlphaAnimation duration:1.0 from:@(1.0) to:@(0.3) autoRevereses:YES];
        // 旋转动画
        CABasicAnimation *rotation = [MyCAHelper myBasicAnimationWithType:kCAHelperRotationAnimation duration:2.0 from:@(-M_PI_2) to:@(M_PI_2) autoRevereses:NO];
        // 缩放动画
        CABasicAnimation *scale = [MyCAHelper myBasicAnimationWithType:kCAHelperScaleAnimation duration:0.5 from:@(1.0) to:@(0.1) autoRevereses:YES];
        
        // 关键帧路径动画，弹力仿真动画效果
        CAKeyframeAnimation *path = [self test1:_demoView.center to:location];
        
        // 2. 设置动画组属性
        [group setAnimations:@[alpha, path, rotation, scale]];
        
        // 设置动画的时长
        [group setDuration:4.0];
        
        // 3. 将动画组添加到图层
        [_demoView.layer addAnimation:group forKey:nil];
}

五、转场动画－CATransition
1⃣属性说明
－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）

－增加一个转场演示视图

－增加轻扫手势
－在轻扫手势方法中

1.更改演示视图内容

2.创建转场动画效果

3.将转场动画添加到视图的图层

// 轻扫手势操作
- (void)swipeAction:(UISwipeGestureRecognizer *)sender
{
        // 通过轻扫手势，让切换出来的视图是蓝色的
        if (_demoView.tag == 0) {
        [_demoView setBackgroundColor:[UIColor blueColor]];
        [_demoView setTag:1];
        } 
        else 
        {
        [_demoView setBackgroundColor:[UIColor redColor]];
        [_demoView setTag:0];
        }
        
        // 根据视图内容我们来实现专场动画
        CATransition *anim = [CATransition animation];
        // 设置专场动画的过渡类型
        [anim setType:@"cameraIrisHollowClose"];
        // 需要根据手势的方向，来决定专场动画的动画方向
        // 注意：在转场动画中，动画方向的左右是和手势的方向相反的
        if (sender.direction == UISwipeGestureRecognizerDirectionLeft) {
        [anim setSubtype:kCATransitionFromRight];
        } else {
        [anim setSubtype:kCATransitionFromLeft];
        }
        
        [_demoView.layer addAnimation:anim forKey:nil];
}

- (void)viewDidLoad
{
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        // 1. 实例化自定义视图
        _demoView = [[UIView alloc]initWithFrame:self.view.bounds];
        [_demoView setBackgroundColor:[UIColor redColor]];
        
        [self.view addSubview:_demoView];
        
        // 2. 增加轻扫手势
        UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc]
        initWithTarget:self
        action:@selector(swipeAction:)];
        [swipeLeft setDirection:UISwipeGestureRecognizerDirectionLeft];
        [_demoView addGestureRecognizer:swipeLeft];
        
        UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc]
        initWithTarget:self
        action:@selector(swipeAction:)];
        [swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];
        [_demoView addGestureRecognizer:swipeRight];
}

六、UIView的转场动画－双视图

+(void)transitionWithView:(UIView*)view duration:(NSTimeInterval)duration options:(UIViewAnimationOptions)options animations:(void(^)(void))animations completion:(void(^)(BOOL finished))completion;

1⃣参数说明
－duration：动画的持续时间

－view：需要进行转场动画的视图

－options：转场动画的类型

－animations：将改变视图属性的代码放在这个Block里

－completion：动画结束后，自动调用的Block

@interface ViewController ()
{
        UIImageView *_demoImageView;
        UIImageView *_demoImageView2;
}
@end

@implementation ViewController

- (void)viewDidLoad
{
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        // 实例化第一个UIImageView的对象
        _demoImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"1.jpg"]];
        [self.view addSubview:_demoImageView];
        
        // 实例化第二个UIImageView对象
        // 注意：在双视图转场动画中，不要将第二个视图添加到主视图
        _demoImageView2 = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"2.jpg"]];
}

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

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
        // 单击屏幕的时候，实现转场动画效果
        [self animation1];
}

#pragma mark - 单视图的转场动画
- (void)animation2
{
        UIImageView *from;
        UIImageView *to;
        
        if (_demoImageView.superview) {
        from = _demoImageView;
        to = _demoImageView2;
        } 
        else 
        {
        from = _demoImageView2;
        to = _demoImageView;
        }
        
        [UIView transitionFromView:from toView:to duration:1.0f options:UIViewAnimationOptionTransitionCrossDissolve completion:^(BOOL finished) {
        NSLog(@"image view1 的主视图： %@", _demoImageView.superview);
        NSLog(@"image view2 的主视图： %@", _demoImageView2.superview);
        }];
}

#pragma mark - 单视图的转场动画
- (void)animation1
{
        [UIView transitionWithView:_demoImageView duration:1.0f options:UIViewAnimationOptionTransitionCurlUp animations:^{
        // 在动画块代码中设置视图内容变化
                if (_demoImageView.tag == 0) {
                        [_demoImageView setImage:[UIImage imageNamed:@"2.jpg"]];
                        [_demoImageView setTag:1];
                } 
                else 
                {
                        [_demoImageView setImage:[UIImage imageNamed:@"1.jpg"]];
                        [_demoImageView setTag:0];
                }
        } completion:nil];
}