FaceBook的POP的動(dòng)畫框架確實(shí)挺好看的，使用起來(lái)也很簡(jiǎn)單。在使用的時(shí)候有幾個(gè)點(diǎn)，也要注意一下。

- (void)clickBottomButtonAction:(UIButton *)sender{

//    self.userInteractionEnabled = NO;
    for (UIButton *button in self.bottomButtonArray) {
        CGRect frame = button.frame;
        frame.origin.y = _originY;
        button.frame = frame;
        button.selected = NO;
    }
    sender.selected = YES;
    POPSpringAnimation *anSpring = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerPositionY];
    anSpring.fromValue = @(_originY);
    anSpring.toValue = @(_originY+10);
    anSpring.delegate = self;
    anSpring.springBounciness = 20.0f;
    [sender pop_addAnimation:anSpring forKey:[NSString stringWithFormat:@"BottomButtonPositionY%ldld",(long)sender.tag]];
//    anSpring.completionBlock = ^(POPAnimation *anim, BOOL finished) {
//        if (finished) {
//            self.userInteractionEnabled = YES;
//        }
//    };
    
}

碰到了一個(gè)這樣的bug，當(dāng)一個(gè)POP動(dòng)畫還沒有結(jié)束，發(fā)起另外一個(gè)POP動(dòng)畫同時(shí)使用frame值去恢復(fù)button的初始狀態(tài)，會(huì)發(fā)現(xiàn)這時(shí)候設(shè)置frame值無(wú)效。 （猜想可能跟pop實(shí)現(xiàn)機(jī)制有關(guān)系）

修改前.gif

解決方法：
1.使用上面代碼注釋中的self.userInteractionEnabled = YES;方法解決，這種解決方案會(huì)讓用戶體驗(yàn)非常差！
2.同樣使用POP動(dòng)畫還原按鈕狀態(tài),demo如下：

    if (_selectButton) {
        self.selectButton.selected = NO;
        POPBasicAnimation *anSpring = [POPBasicAnimation animationWithPropertyNamed:kPOPLayerPositionY];
        CGFloat h = self.selectButton.frame.size.height/6;
        anSpring.toValue =  @(SCREEN_HEIGHT-h);
        [self.selectButton pop_addAnimation:anSpring forKey:[NSString stringWithFormat:@"BottomButtonPositionY%ld",(long)self.selectButton.tag]];
    }
    
    self.selectButton = sender;
    sender.selected = YES;
    POPSpringAnimation *anSpring = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerPositionY];
    anSpring.fromValue = @(_originY);
    anSpring.toValue = @(_originY+10);
    anSpring.springBounciness = 20.0f;
    [sender pop_addAnimation:anSpring forKey:[NSString stringWithFormat:@"BottomButtonPositionY%ld",(long)sender.tag]];

修改后.gif