#import "ViewController.h"@interface ViewController ()@property (weak, nonatomic) IBOutlet UIView *redView;@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 {        CABasicAnimation *anim = [CABasicAnimation animation];    anim.keyPath = @"position.y";    anim.toValue = @400;        /**     *  1:CABasicAnimation:主要用于缩放，平移，转场CATransiton动画主要用于场景切换，CAKeyFrameAnimation：关键帧动画，主要用于图标抖动等       2：在CABasicAnimation中，设置anim.removedOnCompletion，目的是动画结束后不删除动画，anim.fillMode = kCAFillModeForwards;设置动画的模式，设置这两个属性，可以不让动画执行结束后，恢复到原来的位置，而是保留结束动画的状态       3：CAAnimationGroup：她会自动执行数组animations里的动画          */                //    anim.removedOnCompletion = NO;//    anim.fillMode = kCAFillModeForwards;//    //    [self.redView.layer addAnimation:anim forKey:nil];            CABasicAnimation *anim2 = [CABasicAnimation animation];    anim2.keyPath = @"transform.scale";    anim2.toValue = @0.5;//    anim2.removedOnCompletion = NO;//    anim2.fillMode = kCAFillModeForwards;//    [self.redView.layer addAnimation:anim2 forKey:nil];        CAAnimationGroup *group = [CAAnimationGroup animation];    //会自动执行animations数组当中所有的动画对象    group.animations = @[anim,anim2];        group.removedOnCompletion = NO;    group.fillMode = kCAFillModeForwards;    [self.redView.layer addAnimation:group forKey:nil];    }@end