@property (nonatomic, strong) UIDynamicItemBehavior *square1PropertiesBehavior;
@property (nonatomic, strong) UIDynamicItemBehavior *square2PropertiesBehavior;
@property (nonatomic, strong) UIDynamicAnimator *animator;
@property(nonatomic,strong)UIDynamicAnimator*dy;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIView * apple = [[UIView alloc] initWithFrame:CGRectMake(40,40, 40, 40)];
apple.backgroundColor = [UIColor redColor];
[self.view addSubview:apple];
UIDynamicAnimator *animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];
UIGravityBehavior *gravityBeahvior = [[UIGravityBehavior alloc] initWithItems:@[apple]];
UICollisionBehavior *collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[apple]];
UIDynamicItemBehavior*behavior = [[UIDynamicItemBehavior alloc] initWithItems:@[apple]];
//behavior.elasticity = ;
collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;
[animator addBehavior:gravityBeahvior];
[animator addBehavior:collisionBehavior];
[animator addBehavior:behavior];
self.dy = animator; //属性保持才能有动画效果
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}