如何禁用navigationBar动画？

Question

我有两个 UITableViewController，这样当我在第一个 UITableViewController 上单击“下一步”时，第二个 UITableViewController 就会被推送到导航堆栈上并像平常一样对过渡进行动画处理。我想做到这一点，以便当我按下下一步时，只有视图有动画，而导航栏没有（保持不变）。我已经非常接近用下面的代码来做到这一点：

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    CATransition *navTransition = [CATransition animation];
    navTransition.duration = .5;
    navTransition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    navTransition.type = kCATransitionPush;
    navTransition.subtype = kCATransitionPush;
    [self.navigationController.navigationBar.layer addAnimation:navTransition forKey:nil];

}

我放置了这段代码，并且我还制作了它，以便两个导航栏上的标题和按钮在每个 UITableViewController 中完全相同。它几乎可以工作，问题是，动画发生时导航栏会闪烁。有没有办法让它不闪烁，或者有没有其他好的方法来防止导航栏的动画发生（即禁用图层上的动画或其他东西）？

更新：有人还有其他想法吗？仍在为此苦苦挣扎。

Answer 1

这就是我想出来的。以下是序列中第一个视图控制器的代码：

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
        if (viewController == self)
        {
                if (self.isInitialized)
                {
                        CATransition *navigationBarAnimation = [CATransition animation];
                        navigationBarAnimation.duration = 1.5;
                        navigationBarAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];;
                        navigationBarAnimation.type = kCATransitionFade;
                        navigationBarAnimation.subtype = kCATransitionFade;
                        navigationBarAnimation.removedOnCompletion = YES;
                        [self.navigationController.navigationBar.layer addAnimation:navigationBarAnimation forKey:nil];
                }
                else 
                {
                        self.isInitialized = YES;
                }
        }
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
        if (viewController == self)
        {
                if (self.isInitialized)
                {
                        [self.navigationController.navigationBar.layer removeAllAnimations];
                }
        }
}

这是第二个视图控制器的代码：

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
        if (viewController == self)
        {
                if (!self.isInitialized)
                {
                        CATransition *navigationBarAnimation = [CATransition animation];
                        navigationBarAnimation.duration = 1.5;
                        navigationBarAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];;
                        navigationBarAnimation.type = kCATransitionFade;
                        navigationBarAnimation.subtype = kCATransitionFade;
                        navigationBarAnimation.removedOnCompletion = YES;
                        [self.navigationController.navigationBar.layer addAnimation:navigationBarAnimation forKey:nil];
                        self.isInitialized = YES;
                }
        }
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
        if (viewController == self)
        {
                if (self.isInitialized)
                {
                        [self.navigationController.navigationBar.layer removeAllAnimations];
                }
        }
}

您必须使用 UINavigationController 委托方法来确定 UIViewController 何时正在展示。然后，对于每个 UIViewController，需要创建一个 BOOL isInitialized 属性，以便它可以帮助您确定 UIViewController 何时被初始化推入堆栈，或者当您推回下一个 UIViewController 时显示它。

Answer 2

这可能不是最好的答案/想法，但您可以在动画期间屏蔽 UINavigationBar。

创建一个看起来与当前 UNaviationBar 完全相同的 UINavigationBar，将其添加到 keyWindow 中，在转换发生之前，然后在转换发生之后完成删除它。这基本上只覆盖 UINavigationBar 并隐藏其动画。

Answer 3

Swift

这是 swift 中的解决方案

var isInitialized = false

您的 FirstViewController：

func navigationController(_ navigationController: UINavigationController, willShowViewController viewController: UIViewController, animated: Bool) {
        if viewController == self {
            if self.isInitialized {
                var navigationBarAnimation = CATransition()
                navigationBarAnimation.duration = 1.5
                navigationBarAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)
                navigationBarAnimation.type = kCATransitionFade
                navigationBarAnimation.subtype = kCATransitionFade
                navigationBarAnimation.removedOnCompletion = true
                self.navigationController?.navigationBar?.layer?.addAnimation(navigationBarAnimation, forKey: nil)
                }
                else 
                {
                        self.isInitialized = true;
                }
        }
}

func navigationController(_ navigationController: UINavigationController, didShowViewController viewController: UIViewController, animated: Bool) {
        if viewController == self {
            if self.isInitialized {
                self.navigationController?.navigationBar?.layer?.removeAllAnimations()
            }
        }
}

您的 SecondViewController：

func navigationController(_ navigationController: UINavigationController, willShowViewController viewController: UIViewController, animated: Bool) {
        if viewController == self {
            if !self.isInitialized {
                var navigationBarAnimation = CATransition()
                navigationBarAnimation.duration = 1.5
                navigationBarAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)
                navigationBarAnimation.type = kCATransitionFade
                navigationBarAnimation.subtype = kCATransitionFade
                navigationBarAnimation.removedOnCompletion = true
                self.navigationController?.navigationBar?.layer?.addAnimation(navigationBarAnimation, forKey: nil)
                        self.isInitialized = true;
                }
        }
}

func navigationController(_ navigationController: UINavigationController, didShowViewController viewController: UIViewController, animated: Bool) {
        if viewController == self {
            if self.isInitialized {
                self.navigationController?.navigationBar?.layer?.removeAllAnimations()
            }
        }
}