Question

我有三个UIView我希望以某种顺序制作动画（它应该看起来像一个新闻自动收报机，有三个不同的标签从上方移动然后显示然后一直移动到外面风景）。现在整个过程应该无限重复。

这是我使用的代码：

[UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^
{

    [morningPrayerView setFrame:CGRectMake(0, 0, 320, 30)];
    [morningPrayerView setAlpha:1.f];

}
                 completion:^(BOOL finished)
{
    [UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{

        [morningPrayerView setFrame:CGRectMake(0, 30, 320, 30)];
        [morningPrayerView setAlpha:1.f];

    } completion:^(BOOL finished) {
        {
            [UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{

                [middayPrayerView setFrame:CGRectMake(0, 0, 320, 30)];
                [middayPrayerView setAlpha:1.f];

            } completion:^(BOOL finished) {
                {
                    [UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{

                        [middayPrayerView setFrame:CGRectMake(0, 30, 320, 30)];
                        [middayPrayerView setAlpha:1.f];

                    } completion:^(BOOL finished) {
                        {
                            [UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{
                                [eveningPrayerView setFrame:CGRectMake(0, 0, 320, 30)];
                                [eveningPrayerView setAlpha:1.f];


                            } completion:^(BOOL finished) {
                                {
                                    [UIView animateWithDuration:5.0 delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{

                                        [eveningPrayerView setFrame:CGRectMake(0, 30, 320, 30)];
                                        [eveningPrayerView setAlpha:1.f];

                                    } completion:^(BOOL finished) {
                                        //this block is called when the animation is over
                                    }];

                                }                                }];

                        }                        }];

                }                }];

        }        }];

}];

问题是只有第一个动画才能开始，其他动画都没有开始。

Answer 1

恕我直言，UIViewAnimationOptionRepeat开关意味着无限期地重复动画，因此你的第一个动画永远循环，永远不会调用完成处理程序。只需在方法中包装整个动画设置，删除重复开关，并在执行最后一个完成处理程序时再次调用该方法重复整个节目？像这样：

- (void) animateView {
    [UIView animateWithDuration:5.0 animations:^{
        // …
    } completion:^(BOOL finished) {
        [self animateView];
    }];
}

这可能是一个保留周期，但只要你最终取消动画，它应该没问题。

如何让无限动画播放多个动画？

1 个答案: