核心动画（CAKeyframeAnimation）

Main.storyboard

ViewController.m

//

//  ViewController.m

//  8A02.核心动画 - CAKeyframeAnimation

//

//  Created by huan on 16/2/4.

//  Copyright © 2016年 huanxi. All rights reserved.

//

 

#import "ViewController.h"

 

@interface ViewController ()

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

 

@end

 

@implementation ViewController

 

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    //添加一个圆

    CGFloat screenW = [UIScreen mainScreen].bounds.size.width;

    UIView *circleView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, screenW, screenW)];

    circleView.backgroundColor = [UIColor yellowColor];

    //设置圆角

    circleView.layer.cornerRadius = screenW * 0.5;

    [self.view addSubview:circleView];

    //把图片移到顶部

    [self.view bringSubviewToFront:self.imageView];

 

}

 

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    //学习帧动画

    //创建一个帧动画

    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];

    animation.keyPath = @"position";

    //设置动画执行路径 指定四个点

    NSValue *value1 = [NSValue valueWithCGPoint:CGPointMake(50, 50)];

    NSValue *value2 = [NSValue valueWithCGPoint:CGPointMake(250, 50)];

    NSValue *value3 = [NSValue valueWithCGPoint:CGPointMake(250, 250)];

    NSValue *value4 = [NSValue valueWithCGPoint:CGPointMake(50, 250)];

    //数组第一个是"开始状态" 最后一个是“结束状态”

    animation.values = @[value1, value2, value3, value4, value1];

    //设置时间

    animation.duration = 3;

    //设置动画节奏

//    kCAMediaTimingFunctionEaseIn 先慢后快

//    kCAMediaTimingFunctionEaseOut 先慢后快

//    kCAMediaTimingFunctionEaseOut 线性匀速

//    kCAMediaTimingFunctionEaseInEaseOut 中间快两边慢

    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

#warning 内部的path的优先级大于values优先级

    //设置路径

    CGMutablePathRef path = CGPathCreateMutable();

    CGFloat screenW = [UIScreen mainScreen].bounds.size.width;

    CGPathAddEllipseInRect(path, NULL, CGRectMake(0, 0, screenW, screenW));

    animation.path = path;

    //c语言的数据类型，如果create/copy/retain 创建要释放

    //添加动画

    [self.imageView.layer addAnimation:animation forKey:nil];

    

}

@end

结果