iOS 学习 - 24 全局跑马灯,支持后台回到前台

思路：

1.创建一个单例

+ (instancetype)shareManager {
    static CCPaomaView *pModel = nil;
    static dispatch_once_t once;
    dispatch_once(&once, ^{
        pModel = [[CCPaomaView alloc]initWithFrame:CGRectMake(, , KScreenWidth, 0.0468 *KScreenHeight)];
    });
    return pModel;
}

2.使用 FMDB,把接收的数据存在本地的 sqlite,每次取一个数据,动画执行完删除当前数据,再取下一条数据

3.根据动画代理，监听动画执行结束，将动画实例置为 nil

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
    NSLog(@"stopAnimation:%@",[self.paomaLabel.layer animationForKey:@"paoMaDeng"]);
    // 记录运行的动画的时间
    _pmAniamtion.timeOffset = anim.timeOffset;

    // 如果回到前台
    NSString *backStr = [_defaults objectForKey:@"isBack"];
    if ([backStr intValue] == ) {
        if ([self.paomaLabel.layer animationForKey:@"paoMaDeng"] == anim) {

            [_timer invalidate];
            _timer = nil;

            // 动画停止之后，将实例置为 nil
            _pmAniamtion = nil;

            CCPaomaModel *model = [[CCPaomaModel alloc]init];
            // 删除第一个数据
            [model deleteRow:_array[]];
            // 重新再取一次数据(一个)
            _array = [model selectTable];

            // 数组为空之后移除跑马灯
            if (_array.count > ) {
                [self showPaomaView:self.superview];
            }else{
                self.hidden = YES;
                [self removeFromSuperview];
            }
            NSLog(@"%@",self.array);
        }
    }else{
        // 暂停定时器
        [_timer setFireDate:[NSDate distantFuture]];
    }
}

4.判断动画实例是否为空，使得切换界面，跑马灯继续，而不是重新开始

- (void)paomaAniamtion:(CGFloat)count{
    //判断动画实例存不存在，存在继续，不存在即创建
    if (_pmAniamtion == nil) {
        _pmAniamtion = [CABasicAnimation animation];
        _pmAniamtion.keyPath = @"transform.translation.x";
        CGFloat W = CGRectGetWidth(_paomaLabel.bounds);
        _pmAniamtion.fromValue = @(W);
        _pmAniamtion.toValue = @(-W);
        _pmAniamtion.duration = _aniTime;
        _pmAniamtion.repeatCount = count;
        _pmAniamtion.removedOnCompletion = NO;       //动画结束不移除
        _pmAniamtion.fillMode = kCAFillModeForwards; //动画结束会保持结束的状态
        _pmAniamtion.delegate = self;                //设置代理
        [_paomaLabel.layer addAnimation:_pmAniamtion forKey:@"paoMaDeng"];
    }else{
        _pmAniamtion.repeatCount = count;
    }
}

5.切换界面，暂停、恢复动画

- (void)viewWillAppear:(BOOL)animated {

    [_paomaView resumeAnimation];

    if (_paomaView.hidden == YES) {
        [_paomaView showPaomaView:self.view];
    }

    if (_paomaView.array.count > ) {
        [self.view addSubview:_paomaView];
    }
}

- (void)viewWillDisappear:(BOOL)animated {
    [_paomaView pauseAnimation];

    [_paomaView.timer invalidate];
    _paomaView.timer = nil;
}

6.记录回到后台，判断是否执行添加动画方法

- (void)resumeAnimation
{
    if (_array.count > ) {
        CFTimeInterval pausedTime = [_paomaLabel.layer timeOffset];
        _paomaLabel.layer.speed = 1.0;
        _paomaLabel.layer.timeOffset = 0.0;
        _paomaLabel.layer.beginTime = 0.0;
        CFTimeInterval timeSincePause = [_paomaLabel.layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
        _paomaLabel.layer.beginTime = timeSincePause;

        // 是否进入后台
        _defaults = [NSUserDefaults standardUserDefaults];
        NSString *backStr = [_defaults objectForKey:@"isBack"];
        if ([backStr intValue] == ) {

            // 开启定时器
            [_timer setFireDate:[NSDate distantPast]];

            int anmationCount = [_array[] intValue];
            NSLog(@"恢复之后的次数:%d",anmationCount);
            if (anmationCount > ) {
                _pmAniamtion.repeatCount = anmationCount;
                [_paomaLabel.layer addAnimation:_pmAniamtion forKey:@"paoMaDeng"];
            }
            [_defaults setObject:@"" forKey:@"isBack"];
        }
    }
}

话不多说，github 见代码 ( https://github.com/slodier/CCScoops )，觉得好给个 star 呗

转载注明出处： http://www.cnblogs.com/asamu/p/5976557.html