IOS开发核心动画六：动画组

#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

可以同时执行多个动画.

创建组动画

    CAAnimationGroup *group = [CAAnimationGroup animation];

    

    平移

    CABasicAnimation *anim = [CABasicAnimation animation];

    anim.keyPath = @"position.y";

    anim.toValue = @400;

    

    缩放

    CABasicAnimation *scaleAnim = [CABasicAnimation  animation];

    scaleAnim.keyPath = @"transform.scale";

    scaleAnim.toValue = @0.5;

    设置动画组属性

    group.animations = @[anim,scaleAnim];

    

    group.removedOnCompletion = NO;

    group.fillMode = kCAFillModeForwards;

    添加组动画

    [self.redView.layer addAnimation:group forKey:nil];

使用动画组的好处,不需要每次都去添加动画,设置动画完成时的属性.

只需要把要执行的动画,添加到动画组的animations数组当中即可,

最后把组动画添加到层上面,就会自动执行数组当中的动画.

动画完成时设置的属性也只需要设置一次.