呈现 2 个视图控制器，但只有一个过渡

Posted 2023-03-22

【中文标题】呈现 2 个视图控制器，但只有一个过渡

【英文标题】：Present 2 viewcontrollers but only one transition

【发布时间】：2016-03-04 17:39:11

【问题描述】：

我想从视图控制器“A”、第二个视图控制器“B”（带导航栏）推送，它应该显示第三个模式视图控制器“C”，它显示倒计时并自行关闭，最终显示“B ”。

我希望以模态方式呈现“C”，而不会看到“B”，当它被解除时，“B”应该已经存在了。

我一直在看这个帖子：

Present multiple modal view controllers? Presenting a view controller with transparency and animation

但由于我需要推送“B”（不是模态的）我不能使用UIModalPresentationCurrentContext

我也尝试过这样做：How to push two view controllers but animate transition only for the second one?

这几乎是我想要的，但我希望“C”以模态样式呈现，例如垂直封面。

【参考方案1】：

我终于把这两个混合在一起了：

How to push two view controllers but animate transition only for the second one?

NSMutableArray *controllers = [self.navigationController.viewControllers mutableCopy];
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

MyCViewController *vcC = [storyboard instantiateViewControllerWithIdentifier:IDENTIFIER_VC];
MyBViewController *vcB = [storyboard instantiateViewControllerWithIdentifier:IDENTIFIER_VC];

[controllers addObject:vcC];
[controllers addObject:vcB];

self.navigationController.delegate = vcB;
[self.navigationController setViewControllers:controllers animated:YES];

https://www.objc.io/issues/5-ios7/view-controller-transitions/

在 vcB 中：

    -(id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC
    
        if (operation == UINavigationControllerOperationPush || operation == UINavigationControllerOperationPop) 
            MyAnimator *animator = [[MyAnimator alloc] init];
            animator.presenting = (operation == UINavigationControllerOperationPush);
            return animator;
        
        return nil;
    

在 MyAnimator.m 中：

-(NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext

    return 0.4;


-(void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext

    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    [[transitionContext containerView] addSubview:toViewController.view];

    CGRect currentFrame = toViewController.view.frame;
    CGRect toFrameInitial = self.presenting ? CGRectOffset(currentFrame, 0, CGRectGetHeight(currentFrame)) : CGRectOffset(currentFrame, 0, -CGRectGetHeight(currentFrame));
    CGRect fromFrameFinal = self.presenting ? CGRectOffset(currentFrame, 0, -CGRectGetHeight(currentFrame)) : CGRectOffset(currentFrame, 0,   CGRectGetHeight(currentFrame));

    toViewController.view.frame = toFrameInitial;
    [UIView animateWithDuration:[self    transitionDuration:transitionContext] animations:^
        toViewController.view.frame = currentFrame;
        fromViewController.view.frame = fromFrameFinal;
     completion:^(BOOL finished) 
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    ];