@interface ViewController ()

@property (nonatomic,strong) UIButton *button;

    @property (nonatomic,assign) BOOL isSelected;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    [self.view addSubview:self.button ];

    [self.button addTarget:self action:@selector(buttonClick) forControlEvents:UIControlEventTouchUpInside];

    [self.button setBackgroundImage:[UIImage imageNamed:@"deleteButtonNormal"] forState:UIControlStateNormal];

    self.button.backgroundColor = [UIColor orangeColor];

    self.isSelected = YES;

}

//懒加载

- (UIButton *)button{

    if (_button == nil) {

        _button  = [[UIButton alloc]initWithFrame:CGRectMake(, , , )];

    }

    return  _button;

}

- (void)buttonClick{

    POPSpringAnimation *springAnimation = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerSize];

    if (self.isSelected == YES) {

        [_button setBackgroundImage:[UIImage imageNamed:@"deleteButtonSelected"] forState:UIControlStateNormal];

        self.isSelected = NO;

        springAnimation.toValue = [NSValue valueWithCGSize:CGSizeMake(, )];

    }else{

        [_button setBackgroundImage:[UIImage imageNamed:@"deleteButtonNormal"] forState:UIControlStateNormal];

        self.isSelected = YES;

        springAnimation.toValue  = [NSValue valueWithCGSize:CGSizeMake(, )];

    }

    //弹性值

    springAnimation.springBounciness = ;

    //弹性速度

    springAnimation.springSpeed = ;

    [self.button.layer pop_addAnimation:springAnimation forKey:@"changesize"];

}