UIDynamic 入门基础
#import "ViewController.h"
@interface ViewController ()<UICollisionBehaviorDelegate>
{
UIAttachmentBehavior *attachmentBehavior;
UIView *iv;
UIDynamicAnimator *animator;
UIPanGestureRecognizer *panGestureRecognizer;
}
@end
@implementation ViewController
-(void)gesture:(UIPanGestureRecognizer *)gesture{
CGPoint location = [gesture locationInView:self.view];
CGPoint boxLocation = [gesture locationInView:iv];
switch (gesture.state) {
case UIGestureRecognizerStateBegan:{
NSLog(@"you touch started position %@",NSStringFromCGPoint(location));
NSLog(@"location in image started is %@",NSStringFromCGPoint(boxLocation));
[animator removeAllBehaviors];
UIOffset centerOffset = UIOffsetMake(boxLocation.x - CGRectGetMidX(iv.bounds),
boxLocation.y - CGRectGetMidY(iv.bounds));
attachmentBehavior = [[UIAttachmentBehavior alloc] initWithItem:iv
offsetFromCenter:centerOffset
attachedToAnchor:location];//初始化吸附到锚点
attachmentBehavior.damping=0; // 跳跃度
attachmentBehavior.frequency=0;// 幅度
[animator addBehavior:attachmentBehavior];
break;
}
case UIGestureRecognizerStateEnded: {
[animator removeBehavior:attachmentBehavior];
break;
}
default:
[attachmentBehavior setAnchorPoint:[gesture locationInView:self.view]];
break;
}
}
- (void)viewDidLoad {
[super viewDidLoad];
//1.吸附行为（UIAttachmentBehavior）吸附的项有两个属性damping(阻尼)和frequency震荡幅度。
//2.重力行为（UIGravityBehavior）通过对象UIGravityBehavior给动力项指定一个重力矢量，具有重力矢量的动力项，会在重力矢量的方向上一直加速，直到与别的动力项产生了冲突或者遇到了边界。
//3.碰撞行为 (UICollisionBehavior) 通过对象UICollisionBehavior指定一个边界，并且让各个动力项，在该边界内参与碰撞。
//4.推动行为（UIPushBehavior）通过对象UIPushBehavior给动力项指定一个持续的或者瞬时的力
//5.捕捉行为（UISnapBehavior）通过对象UISnapBehavior给动力项指定一个捕捉点。动力项会根据配置的效果，来抓住这一捕捉点。
//6.辅助行为（UIDynamicItemBehavior）用来在item层级设定一些参数，比如item的摩擦，阻力弹性密度和可允许的旋转等。
iv=[[UIView alloc]init];
iv.frame=CGRectMake(100, 100, 100, 100);
iv.backgroundColor=[UIColor redColor];
[self.view addSubview:iv];
animator= [[UIDynamicAnimator alloc] initWithReferenceView:self.view];
// - (void)addBehavior:(UIDynamicBehavior *)behavior;添加指定的行为动画
// - (void)removeBehavior:(UIDynamicBehavior *)behavior;移除指定的行为动画
// - (void)removeAllBehaviors;移除所有的行为
//1.吸附行为（UIAttachmentBehavior）
[self AttachmentBehavior];
//2.重力行为（UIGravityBehavior）
// [self GravityBehavior];
//3.碰撞行为 (UICollisionBehavior)
// [self CollisionBehavior];
//4.推动行为（UIPushBehavior）
// [self PushBehavior];
//5.捕捉行为（UISnapBehavior）
// [self SnapBehavior];
}
-(void)SnapBehavior{
UISnapBehavior *snapbehavior =[[UISnapBehavior alloc]initWithItem:iv snapToPoint:self.view.center];
snapbehavior.damping=1;//damping 振幅大小，默认为0.5f
[animator addBehavior:snapbehavior];
}
-(void)PushBehavior{
UIPushBehavior *push=[[UIPushBehavior alloc]initWithItems:@[iv] mode:UIPushBehaviorModeInstantaneous];
// UIPushBehaviorModeContinuous,一直推动
// UIPushBehaviorModeInstantaneous瞬间推动
push.pushDirection = CGVectorMake(45, 45);//推移的方向（0，0）－》（45，45）
push.magnitude=1;//每一个magnitude将会引起100/平方秒的加速度
[animator addBehavior:push];
UIDynamicItemBehavior *itemBehavior=[[UIDynamicItemBehavior alloc]initWithItems:@[iv]];
itemBehavior.resistance=0.8;//添加阻力。
[animator addBehavior:itemBehavior];
}
-(void)CollisionBehavior{
UIGravityBehavior *gravityBehavior=[[UIGravityBehavior alloc]initWithItems:@[iv]];
[animator addBehavior:gravityBehavior];
UICollisionBehavior *collisionBehavior=[[UICollisionBehavior alloc]initWithItems:@[iv]];
[collisionBehavior setTranslatesReferenceBoundsIntoBoundary:YES];
[animator addBehavior:collisionBehavior];
UIDynamicItemBehavior *itemBehavior = [[UIDynamicItemBehavior alloc]initWithItems:@[iv]];
// @property (readwrite, nonatomic) CGFloat elasticity; // Usually between 0 (inelastic) and 1 (collide elastically) 属性设置碰撞弹性系数 范围（0.0-1.0）决定了碰撞的弹性程度，比如碰撞时物体的弹性
//
// @property (readwrite, nonatomic) CGFloat friction; // 0 being no friction between objects slide along each other设置摩擦系数 决定了沿接触面滑动时的摩擦力大小
//
// @property (readwrite, nonatomic) CGFloat density; // 1 by default 密度 跟size相关 计算物体的总质量 质量越大 物体加速或减速就越困难
//
// @property (readwrite, nonatomic) CGFloat resistance; // 0: no velocity damping （阻力）：决定线性移动的阻力大小 与摩擦系数不同 摩擦系数只作用于滑动运动
//
// @property (readwrite, nonatomic) CGFloat angularResistance; // 0: no angular velocity damping 设置角度阻力系数。（0--CGFLOAT_MAX）决定旋转运动时的阻力大小
//
// @property (readwrite, nonatomic) BOOL allowsRotation; // force an item to never rotate 设置行为中的dynamic item是否可以旋转 设置这个属性为 NO 物体就完全不会转动，而无论施加多大的转动力
[itemBehavior setElasticity:1];
// [itemBehavior setResistance:1];
[animator addBehavior:itemBehavior];
[collisionBehavior setCollisionDelegate:self];
}
- (void)collisionBehavior:(UICollisionBehavior *)behavior
endedContactForItem:(id <UIDynamicItem>)item
withBoundaryIdentifier:(id <NSCopying>)identifier{
NSLog(@"=======");
}
-(void)GravityBehavior{
UIGravityBehavior *gravityBehaviour=[[UIGravityBehavior alloc]initWithItems:@[iv]];
[animator addBehavior:gravityBehaviour];
}
-(void)AttachmentBehavior{
panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(gesture:)];
[iv addGestureRecognizer:panGestureRecognizer];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}