20W以下的项目用不到,20W以上的项目用一点
ViewController.m
#import "ViewController.h"
#define KScreenWidth [UIScreen mainScreen].bounds.size.width
#define KScreenHeight [UIScreen mainScreen].bounds.size.height
@interface ViewController ()
{
UIDynamicAnimator *_animator;
UIView *_viewI;
UIView *_viewII;
}
@end
@implementation ViewController
- (IBAction)gravity:(UIButton *)sender {
/*——————————————————————————————————————————————————————————————————————————————-*/
//2⃣️创建动力学行为 --> 并绑定item(动力学元素)
//重力行为
UIGravityBehavior *gravity = [[UIGravityBehavior alloc]initWithItems:@[_viewI]];
//3⃣️仿真器添加重力行为
[_animator addBehavior:gravity];
//碰撞检测行为
UICollisionBehavior *collision = [[UICollisionBehavior alloc]initWithItems:@[_viewI,_viewII]];
//开启参考边界
collision.translatesReferenceBoundsIntoBoundary = YES;
//仿真器添加碰撞行为
[_animator addBehavior:collision];
}
- (void)viewDidLoad {
[super viewDidLoad];
//1⃣️实例化仿真器 referenceView:参考系
_animator = [[UIDynamicAnimator alloc]initWithReferenceView:self.view];
//创建viewI
_viewI = [[UIView alloc]initWithFrame:CGRectMake(KScreenWidth/2, 20, 50, 50)];
_viewI.backgroundColor = [UIColor blackColor];
_viewI.transform = CGAffineTransformMakeRotation(M_PI_4);
[self.view addSubview:_viewI];
//创建viewII
_viewII = [[UIView alloc]initWithFrame:CGRectMake(0, KScreenHeight/2, KScreenWidth*2/3, 10)];
_viewII.backgroundColor = [UIColor redColor];
[self.view addSubview:_viewII];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
屏幕快照 2016-03-12 下午4.31.41.png
屏幕快照 2016-03-12 下午4.31.00.png
