core Animation之CAAnimationGroup(动画群组)

可以保存一组动画对象，将CAAnimationGroup对象加入层后，组中所有动画对象可以同时并发运行

属性解析：

animations：用来保存一组动画对象的NSArray

默认情况下，一组动画对象是同时运行的，也可以通过设置动画对象的beginTime属性来更改动画的开始时间

#import "ViewController.h"

@interface ViewController ()
@property(nonatomic,strong)UIButton *btn;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.btn=[UIButton buttonWithType:UIButtonTypeCustom];
    self.btn.frame=CGRectMake(50, 100, 80, 60);
    [self.btn setTitle:@"按钮" forState:UIControlStateNormal];
    [self.btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [self.btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.btn];
}
-(void)btnClick:(id)sender
{
    CABasicAnimation *a1 = [CABasicAnimation animation];
    a1.keyPath = @"transform.translation.y";
    a1.toValue = @(100);
    // 缩放动画
    CABasicAnimation *a2 = [CABasicAnimation animation];
    a2.keyPath = @"transform.scale";
    a2.toValue = @(2.0);
    // 旋转动画
    CABasicAnimation *a3 = [CABasicAnimation animation];
    a3.keyPath = @"transform.rotation";
    a3.toValue = @(-3.1415926/4);

    // 组动画
    CAAnimationGroup *groupAnima = [CAAnimationGroup animation];
    groupAnima.animations = @[a1, a2, a3];

    //设置组动画的时间
    groupAnima.duration = 2;
    groupAnima.fillMode = kCAFillModeForwards;
    groupAnima.removedOnCompletion = NO;
    [self.btn.layer addAnimation:groupAnima forKey:nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
@end