目前2個視圖控制器，但只有一個轉換

Question

我想從一個視圖控制器「A」，第二個ViewController「B」（帶有導航欄），它應該顯示第三個模式ViewController「C」，它顯示倒數和解散本身，最後顯示「B」。

我希望模態地呈現「C」，沒有看到「B」，當它被解散時，「B」應該已經在那裏。

我一直在尋找這樣的帖子：

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

但因爲我需要 「B」 被推（非模態），我不能使用UIModalPresentationCurrentContext

我也試過這樣做：How to push two view controllers but animate transition only for the second one?

這幾乎是我想要的，但我希望「C」以模式風格呈現，例如封面垂直。

Answer 1

我終於結束了做這兩個混合：

• 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：

-(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; 
    } 

In MyAnimator.m：

-(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]]; 
    }]; 
}