UITabBarController - 如何制作简单开关的动画？

Question

我对这件事还很陌生。这个应用程序只是我的第二个。

我有一个 TabBarController，有两种在视图之间切换的方法：

方法 1：使用选项卡栏图标。我已经提供了必要的委托回调。它是这样的：

/***************************************************************\**
 \brief This animates the view transitions, and also sets up anything
 that needs doing between views.
 *****************************************************************/
- (BOOL)tabBarController:(UITabBarController *)inTabBarController
shouldSelectViewController:(UIViewController *)inViewController
{
    BOOL ret = NO;

        // Need to have all of these to work.
    if ( inTabBarController && [inTabBarController view] && inViewController && [inViewController view] )
        {
        UIView  *srcView = [[inTabBarController selectedViewController] view];
        UIView  *dstView = [inViewController view];

        if ( srcView != dstView )
            {
            if ( srcView == [prefsController view] )
                {
                [UIView transitionFromView:srcView
                                    toView:dstView
                                  duration:0.25
                                   options:UIViewAnimationOptionTransitionCurlDown
                                completion:nil];
                }
            else if ( dstView == [prefsController view] )
                {
                [UIView transitionFromView:srcView
                                    toView:dstView
                                  duration:0.25
                                   options:UIViewAnimationOptionTransitionCurlUp
                                completion:nil];
                }
            else if ( srcView == [listSearchController view] && dstView == [mapSearchController view] )
                {
                [UIView transitionFromView:srcView
                                    toView:dstView
                                  duration:0.25
                                   options:UIViewAnimationOptionTransitionFlipFromLeft
                                completion:nil];
                }
            else if ( dstView == [listSearchController view] && srcView == [mapSearchController view] )
                {
                [UIView transitionFromView:srcView
                                    toView:dstView
                                  duration:0.25
                                   options:UIViewAnimationOptionTransitionFlipFromRight
                                completion:nil];
                }

            ret = YES;
            }
        }

    return ret;
}

效果很好。

方法 2：抓住滑动，并以这种方式触发转换，如下所示：

/***************************************************************\**
 \brief Gesture Callback -Swipes from the List View to the Map View
 *****************************************************************/
- (IBAction)swipeFromList:(UIGestureRecognizer *)sender
{
    [tabBarController setSelectedIndex:1];
}

这样做的问题是我无法让转换起作用。如果我将转换代码添加到滑动处理程序中，如下所示：

/***************************************************************\**
 \brief Gesture Callback -Swipes from the List View to the Map View
 *****************************************************************/
- (IBAction)swipeFromList:(UIGestureRecognizer *)sender
{
    [UIView transitionFromView:[listSearchController view]
                        toView:[mapSearchController view]
                      duration:0.25
                       options:UIViewAnimationOptionTransitionFlipFromLeft
                    completion:nil];
    [tabBarController setSelectedIndex:1];
}

它第一次工作，但在后续操作中出现蛇眼。

我确信我在这里犯了一些基本的、可笑的错误，并且正在寻找线索。

线索，有人吗？

谢谢！

Answer 1

哇。我解决了它，我不太清楚为什么，但它有效。

这就是我所做的：

首先，我将转换分解为标准方法：

/***************************************************************\**
 \brief Manages the transition from one view to another. Just like
 it says on the tin.
 *****************************************************************/
- (void)transitionBetweenThisView:(UIView *)srcView
                      andThisView:(UIView *)dstView
{
    if ( srcView != dstView )
        {
        if ( srcView == [prefsController view] )
            {
            [UIView transitionFromView:srcView
                                toView:dstView
                              duration:0.25
                               options:UIViewAnimationOptionTransitionCurlDown
                            completion:nil];
            }
        else if ( dstView == [prefsController view] )
            {
            [UIView transitionFromView:srcView
                                toView:dstView
                              duration:0.25
                               options:UIViewAnimationOptionTransitionCurlUp
                            completion:nil];
            }
        else if ( srcView == [listSearchController view] && dstView == [mapSearchController view] )
            {
            [UIView transitionFromView:srcView
                                toView:dstView
                              duration:0.25
                               options:UIViewAnimationOptionTransitionFlipFromLeft
                            completion:nil];
            }
        else if ( dstView == [listSearchController view] && srcView == [mapSearchController view] )
            {
            [UIView transitionFromView:srcView
                                toView:dstView
                              duration:0.25
                               options:UIViewAnimationOptionTransitionFlipFromRight
                            completion:nil];
            }
        }
}

接下来，我在标签栏转换发生之前拦截它，并覆盖它，如下所示：

/***************************************************************\**
 \brief This animates the view transitions, and also sets up anything
 that needs doing between views. It stops the tab bar controller
 from managing the transition, and does it manually.
 \returns a BOOL. Always NO.
 *****************************************************************/
- (BOOL)tabBarController:(UITabBarController *)inTabBarController
 shouldSelectViewController:(UIViewController *)inViewController
{
    [self transitionBetweenThisView:[[inTabBarController selectedViewController] view] andThisView:[inViewController view]];
    int index = [[inTabBarController viewControllers] indexOfObject:inViewController];
    [inTabBarController setSelectedIndex:index];
    return NO;
}

然后，我将以下代码添加到滑动陷阱中：

/***************************************************************\**
 \brief Gesture Callback -Swipes from the List View to the Map View
 *****************************************************************/
- (IBAction)swipeFromList:(UIGestureRecognizer *)sender
{
    [self transitionBetweenThisView:[listSearchController view] andThisView:[mapSearchController view]];
    [tabBarController setSelectedIndex:1];
}

现在，这里的问题是，当我返回到我滑动的视图（不使用选项卡栏）时，我总是会崩溃。崩溃表明目标视图已被取消分配。

在检查了一些鸡内脏后，我决定我需要捂住鼻子，并保留之前的观点，就像这样：

    [[listSearchController view] retain];
    [self transitionBetweenThisView:[listSearchController view] andThisView:[mapSearchController view]];

可以。我用仪器检查过。没有泄漏。

Answer 2

此代码运行良好 **

int controllerIndex = 2;
UIView * fromView = self.tabBarController .selectedViewController.view;
UIView * toView = [[self.tabBarController.viewControllers objectAtIndex:controllerIndex] view];

// Transition using a page curl.
[UIView transitionFromView:fromView toView:toView duration:0.5
                   options:(controllerIndex > self.tabBarController.selectedIndex ? UIViewAnimationOptionTransitionCurlUp : UIViewAnimationOptionTransitionCurlDown)

                completion:^(BOOL finished) {

                    if (finished) {
                        self.tabBarController.selectedIndex = controllerIndex;
                    }

                }];**