粒子动画

@property(nonatomic, strong) CAEmitterLayer *emitterLayer;

static CGFloat PI = M_PI;

• (void)viewDidLoad {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  self.emitterLayer;
  // [self animateInView:self.view];
  // [NSTimer scheduledTimerWithTimeInterval:0.3
  // target:self
  // selector:@selector(click)
  // userInfo:nil
  // repeats:YES];
  }

-(void)click {
[self animateInView:self.view];
}

-(void)animateInView:(UIView *)view {
UIImageView *imageView = [[UIImageView alloc] init];
imageView.backgroundColor = [UIColor yellowColor];
imageView.frame = CGRectMake(100, 400, 30, 30);
int nameI = arc4random() % 8 + 1;
UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"icon_fanpian_0%d.png",nameI]];
imageView.image = image;

[view addSubview:imageView];

// Pre-Animation setup
imageView.transform = CGAffineTransformMakeScale(0, 0);
imageView.alpha = 0;

//在底部 由无到有 又小变大的弹性动画
[UIView animateWithDuration:0.5
                      delay:0.0
     usingSpringWithDamping:0.6
      initialSpringVelocity:0.8
                    options:UIViewAnimationOptionCurveEaseOut
                 animations:^{
                     imageView.transform = CGAffineTransformIdentity;
//                       imageView.transform = CGAffineTransformScale(imageView.transform, 4, 4);
                     imageView.alpha = 0.9;
                 }
                 completion:NULL];
NSInteger i = arc4random_uniform(2);
NSInteger rotationDirection = 1 - (2 * i); // -1 OR 1
NSInteger rotationFraction = arc4random_uniform(10);

NSTimeInterval totalAnimationDuration = 3;
//放大后向左或向右旋转一定角度动画
[UIView
 animateWithDuration:totalAnimationDuration
 animations:^{
     imageView.transform = CGAffineTransformMakeRotation(  rotationDirection * M_PI / (16 + rotationFraction * 0.2));
 }
 completion:NULL];

// S型动画
CGFloat heartSize = CGRectGetWidth(imageView.bounds);
CGFloat heartCenterX = imageView.center.x;
CGFloat viewHeight = CGRectGetHeight(view.bounds);

UIBezierPath *heartTravelPath = [UIBezierPath bezierPath];
[heartTravelPath moveToPoint:imageView.center];

// 随机结束点
CGPoint endPoint = CGPointMake( heartCenterX + (rotationDirection)*arc4random_uniform(2 * heartSize),
                               viewHeight / 6.0 + arc4random_uniform(viewHeight / 4.0));
NSInteger j = arc4random_uniform(2);
NSInteger travelDirection = 1 - (2 * j); // -1 OR 1

//绘制S型曲线 随机点
CGFloat xDelta = (heartSize / 2.0 + arc4random_uniform(2 * heartSize)) * travelDirection;
CGFloat yDelta =  MAX(endPoint.y, MAX(arc4random_uniform(8 * heartSize), heartSize));

//控制点1 控制点2
CGPoint controlPoint1 = CGPointMake(heartCenterX + xDelta, yDelta);
CGPoint controlPoint2 = CGPointMake(heartCenterX - xDelta, yDelta);

// CGPoint controlPoint1 = CGPointMake(heartCenterX + xDelta, viewHeight - yDelta);
// CGPoint controlPoint2 = CGPointMake(heartCenterX - 2 * xDelta, yDelta);

[heartTravelPath addCurveToPoint:endPoint
                   controlPoint1:controlPoint1
                   controlPoint2:controlPoint2];
CAKeyframeAnimation *keyFrameAnimation =
[CAKeyframeAnimation animationWithKeyPath:@"position"];
keyFrameAnimation.path = heartTravelPath.CGPath;
keyFrameAnimation.timingFunction =
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
keyFrameAnimation.duration = totalAnimationDuration + endPoint.y / viewHeight;
[imageView.layer addAnimation:keyFrameAnimation forKey:@"positionOnPath"];

// 动画消失
[UIView animateWithDuration:totalAnimationDuration
                 animations:^{
                     imageView.alpha = 0.0;
                 }
                 completion:^(BOOL finished) {
                     [imageView removeFromSuperview];
                 }];
dispatch_after(
               dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)),
               dispatch_get_main_queue(), ^{
               });

}

• (CAEmitterLayer *)emitterLayer {
  if (!_emitterLayer) {
  CAEmitterLayer *emitterLayer = [CAEmitterLayer layer];

  // 发射器在xy平面的中心位置
  emitterLayer.emitterPosition = CGPointMake(self.view.frame.size.width - 50, self.view.frame.size.height - 50);
  // 发射器的尺寸大小
  emitterLayer.emitterSize = CGSizeMake(20, 20);
  // 渲染模式
  emitterLayer.renderMode = kCAEmitterLayerUnordered;
  // 开启三维效果
  _emitterLayer.preservesDepth = YES;
  NSMutableArray *array = [NSMutableArray array];
  // 创建粒子
  for (int i = 0; i < 8; i++) {
  // 发射单元
  CAEmitterCell *stepCell = [CAEmitterCell emitterCell];
  // 粒子的创建速率，默认为1/s
  stepCell.birthRate = 1;
  // 粒子存活时间
  stepCell.lifetime = arc4random_uniform(4) + 1;
  // 粒子的生存时间容差
  stepCell.lifetimeRange = 1.5;
  // 颜色
  // fire.color=[[UIColor colorWithRed:0.8 green:0.4 blue:0.2 alpha:0.1]CGColor];
  UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"icon_fanpian_0%d.png",i+1]];
  // 粒子显示的内容
  stepCell.contents = (id)[image CGImage];
  // 粒子的名字
  //[fire setName:@"step%d", i];
  // 粒子的运动速度
  stepCell.velocity = arc4random_uniform(100) + 100;
  // 粒子速度的容差
  stepCell.velocityRange = 80;
  // 粒子在xy平面的发射角度
  stepCell.emissionLongitude = M_PI + M_PI_2;
  ;
  // 粒子发射角度的容差
  stepCell.emissionRange = M_PI_2 / 6;
  // 缩放比例
  stepCell.scale = 0.3;
  [array addObject:stepCell];
  }

    emitterLayer.emitterCells = array;
    emitterLayer.backgroundColor = [UIColor redColor].CGColor;
    [self.view.layer addSublayer:emitterLayer];
    _emitterLayer = emitterLayer;
  

  }
  return _emitterLayer;
  }