购物篮动画

//
//  ViewController.m
//  test
//
//  Created by hqw on 16/4/20.
//  Copyright © 2016年 hgs. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (weak, nonatomic) IBOutlet UIButton *btn;
@property (nonatomic, strong) NSMutableArray *layerArray;
@end

@implementation ViewController
//记录用户点击次数
static NSInteger i = 0;
static NSInteger j = 0;
- (NSMutableArray *)layerArray {
    if (_layerArray == nil) {
        _layerArray = [[NSMutableArray alloc] init];
    }
    return _layerArray;
}

- (IBAction)btnClick:(UIButton *)sender {
    CALayer *layer = [CALayer layer];
    //将产生的layer添加进数组
    [self.layerArray addObject:layer];
    layer.frame = sender.frame;
    UIImage *image = [UIImage imageNamed:@"btn_add_cart"];
    layer.contents = (id)image.CGImage;
    [self.view.layer addSublayer:layer];
    //path
    UIBezierPath *path = [UIBezierPath bezierPath];
    [path moveToPoint:sender.center];
    CGFloat x = (self.imageView.center.x - sender.center.x) / 2.0 - 50;
    CGFloat y = (sender.center.y - self.imageView.center.y) / 2;
    [path addQuadCurveToPoint:self.imageView.center controlPoint:CGPointMake(sender.center.x + x, y)];
    
    
    [self startAnimation:path layer:layer];
}

- (void)startAnimation:(UIBezierPath *)path layer:(CALayer *)layer {
    CAAnimationGroup *group = [CAAnimationGroup animation];
    CAKeyframeAnimation *keyAnim = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    keyAnim.path = path.CGPath;
    CABasicAnimation *baseAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
    baseAnim.toValue = @0.01;
    group.animations = @[keyAnim, baseAnim];
    group.duration = 1;
    group.delegate = self;
    [layer addAnimation:group forKey:nil];
}

- (void)animationDidStart:(CAAnimation *)anim {
    i++;
}
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
    //动画结束,遍历移除layer
    //可能有人会直接用属性引用layer移除,但是如果用户快速点多次,那么layer就不会移除了,所以,用数组来记录
    j++;
    if (i == j) {//i==j的时候,说明所有的动画都结束了,这个时候就移除所有layer
        for (CALayer *layer in self.layerArray) {
            [layer removeFromSuperlayer];
        }
        //记得清空数组
        [self.layerArray removeAllObjects];
    }
}