ios - 如何禁用导航栏动画？

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 会被推送到导航堆栈上，并像往常一样为过渡设置动画。我想做到这一点，所以当我接下来按下时，只有 View 有动画，而导航栏没有(保持不变)。我已经非常接近于使用以下代码执行此操作:

- (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，因此两个导航栏上的标题和按钮在每个 UITableViewController 中都完全相同。它几乎可以工作，问题是，动画出现时导航栏会闪烁。无论如何让它不闪烁，或者是否有任何其他好的方法来防止导航栏的动画发生(即禁用层上的动画或其他东西)？

更新:有人有任何其他想法吗？仍在为此苦苦挣扎。

Answer 1

这是我想出来的。这是序列中第一个 viewController 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 View Controller 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(delegate)方法来确定何时显示 UIViewController。然后对于每个 UIViewController，需要创建一个 BOOL isInitialized 属性，这样它可以帮助您确定 UIViewController 何时被初始化插入堆栈，或者当它显示时，因为您推回了下一个 UIViewController。