UIDynamic使用

//
//  ViewController.m
//  UIDynamic
//
//  Created by hq on 16/5/3.
//  Copyright © 2016年 hanqing. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIImageView *ball;

@property (weak, nonatomic) IBOutlet UIView *bottomVIew;

@property(nonatomic,strong) UIDynamicAnimator *anim;

@end

@implementation ViewController

-(UIDynamicAnimator *)anim{
    
    //设置仿真范围
    if (_anim==nil) {
        _anim=[[UIDynamicAnimator alloc]initWithReferenceView:self.view];
    }
    return _anim;
}


- (void)viewDidLoad {
    [super viewDidLoad];
    
    
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    
    UITouch *touch=[touches anyObject];
    
    CGPoint currentP=[touch locationInView:self.view];
    
    //创建一个捕捉行为
    UISnapBehavior *snap=[[UISnapBehavior alloc]initWithItem:self.ball snapToPoint:currentP];
    
    //防抖系数，越小，越抖，最大值为1
    snap.damping=0;
    
    //必须清空上一次的才能继续使用
    [self.anim removeAllBehaviors];
    
    [self.anim addBehavior:snap];

}

-(void) testCollisionBehaviorByPath{
    
    //创建一个碰撞行为
    UICollisionBehavior *coll=[[UICollisionBehavior alloc] init];
    //添加一个碰撞的边界（路径）
    
    UIBezierPath *path=[UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.width)];
    
    
    [coll addBoundaryWithIdentifier:@"path" forPath:path];
    
    [coll addItem:self.ball];
    //[coll addItem:self.bottomVIew];
    
    UIGravityBehavior *grav=[[UIGravityBehavior alloc] init];
    [grav addItem:self.ball];
    
    
    [self.anim addBehavior:coll];
    [self.anim addBehavior:grav];
    
}

//碰撞边界为用线围起来的一块区域
-(void) testCollisionBehavior1{
    
    //创建一个碰撞行为
    UICollisionBehavior *coll=[[UICollisionBehavior alloc] init];
    //添加一个碰撞的边界
    [coll addBoundaryWithIdentifier:@"line1" fromPoint:CGPointMake(0, 0) toPoint:CGPointMake(0, self.view.bounds.size.height*0.5)];
    
    [coll addBoundaryWithIdentifier:@"line2" fromPoint:CGPointMake(0, self.view.bounds.size.height*0.5) toPoint:CGPointMake(self.view.bounds.size.width, self.view.bounds.size.height)];
    
    [coll addItem:self.ball];
    [coll addItem:self.bottomVIew];
    
    UIGravityBehavior *grav=[[UIGravityBehavior alloc] init];
    [grav addItem:self.ball];
    
    
    [self.anim addBehavior:coll];
    [self.anim addBehavior:grav];
}

//重力仿真器
-(void) testGravity{
    
    //创建xx的仿真行为
    UIGravityBehavior *grav=[[UIGravityBehavior alloc]init];
    
    [grav addItem:self.ball];
    
    [self.anim addBehavior:grav];
    
}


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

@end