动力效果 UIGravityBehavior- UICollisionBehavior- UIDynamicItemBehavior

<p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"><span style="font-family: 'Heiti SC Light';">使用</span>UIDynamic <span style="font-family: 'Heiti SC Light';">步骤</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> 1<span style="font-family: 'Heiti SC Light';">、创建一个动力效果器</span>(UIDynamicAnimator)</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';"> 2</span>、创建动力效果<span style="font-family: 'Andale Mono';">(Behavior)</span>添加到对应的视图上</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';"> 3</span>、将动力效果添加到动力效果器中，开始动力效果了</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;">上面的<span style="font-family: 'Andale Mono';">3</span>个相当于，创建一个容器对象<span style="font-family: 'Andale Mono';">A</span>，再创建另一个对象<span style="font-family: 'Andale Mono';">B</span>，把<span style="font-family: 'Andale Mono';">B</span>放入<span style="font-family: 'Andale Mono';">A</span>中，再让<span style="font-family: 'Andale Mono';">B</span>动起来，那么<span style="font-family: 'Andale Mono';">A</span>看起来就有动力效果了<span style="font-family: 'Andale Mono';">//----</span>自解释</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;">
</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;">UIDynamic<span style="font-family: 'Heiti SC Light';">提供的动力效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UIGravityBehavior<span style="font-family: 'Heiti SC Light';">：重力效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UICollisionBehavior<span style="font-family: 'Heiti SC Light';">：碰撞效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UIDynamicItemBehavior<span style="font-family: 'Heiti SC Light';">：动力元素效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UIPushBehavior<span style="font-family: 'Heiti SC Light';">：推动效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UISnapBehavior<span style="font-family: 'Heiti SC Light';">：迅速移动效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UIAttachmentBehavior<span style="font-family: 'Heiti SC Light';">：附着效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;">
</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;"></span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';">动力效果器：</span>UIDynamicAnimator</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="font-family: 'Andale Mono';"> </span>可以把<span style="font-family: 'Andale Mono';">UIDynamicAnimator</span>看做动力效果的容器<span style="font-family: 'Andale Mono';"> </span>它制定了动力效果的有效范围</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="font-family: 'Andale Mono';"> </span>在初始化的时候可以指定他的有效范围</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (instancetype)initWithReferenceView:(UIView*)view;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="font-family: 'Andale Mono';"> </span>作用在哪一个<span style="font-family: 'Andale Mono';">view</span>上<span style="font-family: 'Andale Mono';"> </span>哪一个<span style="font-family: 'Andale Mono';">view</span>就是他产生动力效果的有效范围</p>
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;"></span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';">既然是容器<span style="font-family: 'Andale Mono';">  </span>他还可以添加移除<span style="font-family: 'Andale Mono';"> </span>动力效果</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)addBehavior:(UIDynamicBehavior *)behavior; <span style="font-family: 'Heiti SC Light';">添加动力效果</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)removeBehavior:(UIDynamicBehavior *)behavior; <span style="font-family: 'Heiti SC Light';">移除动力效果</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)removeAllBehaviors; <span style="font-family: 'Heiti SC Light';">移除之前添加过的所有动力效果</span></p>
<p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;"></span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';">动力效果器常用的属性</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, readonly) UIView* referenceView;<span style="font-family: 'Heiti SC Light';">作用的区域</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, readonly, copy) NSArray* behaviors;<span style="font-family: 'Heiti SC Light';">添加到效果器中的所有效果</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, readonly, getter = isRunning) BOOL running;<span style="font-family: 'Heiti SC Light';">是否正在进行</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, assign) id <UIDynamicAnimatorDelegate> delegate;<span style="font-family: 'Heiti SC Light';">可以检测开始暂停</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)dynamicAnimatorWillResume:(UIDynamicAnimator*)animator;</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)dynamicAnimatorDidPause:(UIDynamicAnimator*)animator;</p>
<div><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;"></span></span><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="font-family: 'Heiti SC Light';">重力效果：</span>UIGravityBehavior</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="font-family: 'Andale Mono';"> </span>设置重力方向<span style="font-family: 'Andale Mono';"> </span>加速度<span style="font-family: 'Andale Mono';"> </span>让<span style="font-family: 'Andale Mono';">(</span>视图<span style="font-family: 'Andale Mono';">)</span>朝着重力方向掉落</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, readonly, copy) NSArray *items;<span style="font-family: 'Heiti SC Light';">添加到重力效果中的所有效果作用对象</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (readwrite, nonatomic) CGVector gravityDirection;<span style="font-family: 'Heiti SC Light';">重力方向（是一个二维向量）以左上角为坐标原点</span> x <span style="font-family: 'Heiti SC Light';">负数向左</span> <span style="font-family: 'Heiti SC Light';">正数向右</span>  y <span style="font-family: 'Heiti SC Light';">负数向上</span>  <span style="font-family: 'Heiti SC Light';">正数向下</span>  <span style="font-family: 'Heiti SC Light';">数字越大</span>  <span style="font-family: 'Heiti SC Light';">重力效果越大</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (readwrite, nonatomic) CGFloat angle;<span style="font-family: 'Heiti SC Light';">重力方向（是一个角度，</span>x<span style="font-family: 'Heiti SC Light';">轴正方向为</span>0°<span style="font-family: 'Heiti SC Light';">，顺时针正数，逆时针负数）</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (readwrite, nonatomic) CGFloat magnitude;<span style="font-family: 'Heiti SC Light';">量级（用来控制加速度，</span>1.0<span style="font-family: 'Heiti SC Light';">代表加速度是</span>1000 points /second²<span style="font-family: 'Heiti SC Light';">）重力加速度越大</span> <span style="font-family: 'Heiti SC Light';">碰撞越厉害</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"> </p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="font-family: 'Andale Mono';"> </span>边界相关的方法</p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)addBoundaryWithIdentifier:(id <NSCopying>)identifier forPath:(UIBezierPath*)bezierPath; <span style="font-family: 'Heiti SC Light';">添加一个贝塞尔曲线路径的边界</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)addBoundaryWithIdentifier:(id <NSCopying>)identifier fromPoint:(CGPoint)p1 toPoint:(CGPoint)p2; <span style="font-family: 'Heiti SC Light';">通过添加两个点连成的线</span> <span style="font-family: 'Heiti SC Light';">作为边界</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (UIBezierPath*)boundaryWithIdentifier:(id <NSCopying>)identifier; <span style="font-family: 'Heiti SC Light';">通过</span>ID<span style="font-family: 'Heiti SC Light';">找到边界路径</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)removeBoundaryWithIdentifier:(id <NSCopying>)identifier; <span style="font-family: 'Heiti SC Light';">移除</span>ID<span style="font-family: 'Heiti SC Light';">对应的边界</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> @property (nonatomic, readonly, copy) NSArray* boundaryIdentifiers; <span style="font-family: 'Heiti SC Light';">边界数组</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"> - (void)removeAllBoundaries;<span style="font-family: 'Heiti SC Light';">移除所有边界</span></p>
</div><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';">//</span>两个元素相互碰撞</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> - (void)collisionBehavior:(UICollisionBehavior*)behavior beganContactForItem:(id <UIDynamicItem>)item1 withItem:(id <UIDynamicItem>)item2 atPoint:(CGPoint)p;</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> - (void)collisionBehavior:(UICollisionBehavior*)behavior endedContactForItem:(id <UIDynamicItem>)item1 withItem:(id <UIDynamicItem>)item2;</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';"> // </span>视图碰撞边界的时候<span style="font-family: 'Andale Mono';"> </span>触发</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> - (void)collisionBehavior:(UICollisionBehavior*)behavior beganContactForItem:(id <UIDynamicItem>)item withBoundaryIdentifier:(id <NSCopying>)identifier atPoint:(CGPoint)p;</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> - (void)collisionBehavior:(UICollisionBehavior*)behavior endedContactForItem:(id <UIDynamicItem>)item withBoundaryIdentifier:(id <NSCopying>)identifier;</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono'; min-height: 20px;"><span style="color:#3333ff;"> </span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UIDynamicItemBehavior <span style="font-family: 'Heiti SC Light';">动力元素效果</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';"> </span>可以设置<span style="font-family: 'Andale Mono';"> </span>动力效果的默认值<span style="font-family: 'Andale Mono';"> </span>是一个辅助的效果<span style="font-family: 'Andale Mono';"> </span>设置运动学元素参与物理效果过程中的参数<span style="font-family: 'Andale Mono';"> </span>如：弹性系数、摩擦系数、密度、阻力、角阻力以及是否允许旋转等</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light';"><span style="color:#3333ff;"><span style="font-family: 'Andale Mono';"> </span>常用属性</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) CGFloat elasticity; // Usually between 0 (inelastic) and 1 (collide elastically) <span style="font-family: 'Heiti SC Light';">属性设置碰撞弹性系数</span> <span style="font-family: 'Heiti SC Light';">范围（</span>0.0-1.0<span style="font-family: 'Heiti SC Light';">）决定了碰撞的弹性程度，比如碰撞时物体的弹性</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) CGFloat friction; // 0 being no friction between objects slide along each other<span style="font-family: 'Heiti SC Light';">设置摩擦系数</span> <span style="font-family: 'Heiti SC Light';">决定了沿接触面滑动时的摩擦力大小</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) CGFloat density; // 1 by default <span style="font-family: 'Heiti SC Light';">密度</span>   <span style="font-family: 'Heiti SC Light';">跟</span>size<span style="font-family: 'Heiti SC Light';">相关</span> <span style="font-family: 'Heiti SC Light';">计算物体的总质量</span> <span style="font-family: 'Heiti SC Light';">质量越大</span> <span style="font-family: 'Heiti SC Light';">物体加速或减速就越困难</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) CGFloat resistance; // 0: no velocity damping <span style="font-family: 'Heiti SC Light';">（阻力）：决定线性移动的阻力大小</span> <span style="font-family: 'Heiti SC Light';">与摩擦系数不同</span> <span style="font-family: 'Heiti SC Light';">摩擦系数只作用于滑动运动</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) CGFloat angularResistance; // 0: no angular velocity damping <span style="font-family: 'Heiti SC Light';">设置角度阻力系数。（</span>0--CGFLOAT_MAX<span style="font-family: 'Heiti SC Light';">）决定旋转运动时的阻力大小</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> @property (readwrite, nonatomic) BOOL allowsRotation; // force an item to never rotate <span style="font-family: 'Heiti SC Light';">设置行为中的</span>dynamic item<span style="font-family: 'Heiti SC Light';">是否可以旋转</span>  <span style="font-family: 'Heiti SC Light';">设置这个属性为</span> NO <span style="font-family: 'Heiti SC Light';">物体就完全不会转动，而无论施加多大的转动力</span></span></p><div><span style="font-family: 'Heiti SC Light';"><span style="color:#3333ff;">
</span></span></div><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;">typedef NS_OPTIONS(NSUInteger, UICollisionBehaviorMode) {</span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UICollisionBehaviorModeItems        = 1 << 0,<span style="font-family: 'Heiti SC Light';">元素碰撞</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UICollisionBehaviorModeBoundaries   = 1 << 1,<span style="font-family: 'Heiti SC Light';">边界碰撞</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> UICollisionBehaviorModeEverything   = NSUIntegerMax <span style="font-family: 'Heiti SC Light';">全体碰撞</span></span></p><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Andale Mono';"><span style="color:#3333ff;"> } NS_ENUM_AVAILABLE_IOS(7_0);</span></p><span style="color:#4bd157;">
</span><p style="margin-top: 0px; margin-bottom: 0px; font-size: 18px; font-family: 'Heiti SC Light'; color: rgb(75, 209, 87);">
</p><div>
</div>

#import "ViewController.h"@interface ViewController ()<UIDynamicAnimatorDelegate,UICollisionBehaviorDelegate>{UIDynamicAnimator *dynamicAnimatorxx;UIView *view01;UIView *view02;UIImageView *blastEffet;}@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];self.view.backgroundColor = [UIColor blackColor];<span style="font-size:24px;">#pragma mark————两个元素相互碰撞————</span>//*************************************************************************//    动力效果容器dynamicAnimatorxx = [[UIDynamicAnimator alloc]initWithReferenceView:self.view];//Reference:指的是-参考，self.view就是产生动力效果的参考区域dynamicAnimatorxx.delegate = self;view01 = [[UIView alloc]initWithFrame:CGRectMake(CGRectGetWidth([UIScreen mainScreen].bounds)/2-25, 25, 10, 100)];view01.backgroundColor = [UIColor redColor];view01.layer.cornerRadius = 25;view01.tag = 10;[self.view addSubview:view01];view02 = [[UIView alloc]initWithFrame:CGRectMake(CGRectGetWidth([UIScreen mainScreen].bounds)/2-25, 25, 10, 100)];view02.backgroundColor = [UIColor blueColor];view02.layer.cornerRadius = 25;;[self.view addSubview:view02];//*************************************************************************}<span style="font-size:24px;">#pragma mark————触摸屏幕 添加动力效果 并执行————</span>-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{UITouch *touch = [touches anyObject];CGPoint touchPoint = [touch locationInView:self.view];view02.center = touchPoint;}-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{<span style="font-size:24px;">#pragma mark——添加的重力效果——</span>[dynamicAnimatorxx removeAllBehaviors];UIGravityBehavior *gravity = [[UIGravityBehavior alloc]initWithItems:@[view01,view02]];gravity.gravityDirection = CGVectorMake(0, -1);[dynamicAnimatorxx addBehavior:gravity];<span style="font-size:24px;">#pragma mark——添加的碰撞效果——</span>UICollisionBehavior *collision = [[UICollisionBehavior alloc]initWithItems:@[view01,view02]];//*************************************************************************collision.translatesReferenceBoundsIntoBoundary = YES;collision.collisionDelegate = self;[dynamicAnimatorxx addBehavior:collision];//*************************************************************************<span style="font-size:24px;">#pragma mark——添加动力元素效果——</span><span style="font-size:18px;">//    可与其它的动力效果 配合使用</span>UIDynamicItemBehavior *itemxx = [[UIDynamicItemBehavior alloc]initWithItems:@[view01,view02]];itemxx.elasticity = 1;//设置元素的跳跃度itemxx.angularResistance = 0;itemxx.friction = 0;itemxx.resistance = 0;[dynamicAnimatorxx addBehavior:itemxx];}<span style="font-size:24px;">#pragma mark--下面两个是碰撞代理</span>- (void)collisionBehavior:(UICollisionBehavior*)behavior beganContactForItem:(id <UIDynamicItem>)item1 withItem:(id <UIDynamicItem>)item2 atPoint:(CGPoint)p{NSLog(@"撞 的位置 X:%f Y:%f",p.x,p.y);}- (void)collisionBehavior:(UICollisionBehavior*)behavior endedContactForItem:(id <UIDynamicItem>)item1 withItem:(id <UIDynamicItem>)item2{}