为什么不调用UIViewControllerTransitioningDelegate方法presentationControllerForPresentedViewController？

Question

我想使用自定义的UIPresentationController。 对于它，当我想表明新的场景我把这个代码

UIViewController *cv = [[...]]; 

cv.transitionManager=[[MyTransition alloc] init]; 
cv.transitioningDelegate=actionSheet.transitionManager; 
cv.modalTransitionStyle = UIModalPresentationCustom; 

[self presentViewController:cv animated:YES completion:^{ 

}]; 

我的过渡经理方法：

#pragma mark - UIViewControllerTransitioningDelegate 

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source{ 
    return self; 
} 

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed{ 
    return self; 
} 

- (id <UIViewControllerInteractiveTransitioning>)interactionControllerForPresentation:(id <UIViewControllerAnimatedTransitioning>)animator{ 
    return nil; 
} 

- (id <UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id <UIViewControllerAnimatedTransitioning>)animator{ 
    return self; 
} 


- (UIPresentationController *)presentationControllerForPresentedViewController:(UIViewController *)presented presentingViewController:(UIViewController *)presenting sourceViewController:(UIViewController *)source { 
    MyPresentationController *presentationController = [[MyPresentationController alloc] initWithPresentedViewController:presented presentingViewController:presenting]; 
    return presentationController; 
} 

但该方法presentationControllerForPresentedViewController不来电！

为什么？

Answer 1

它只会如果你现在使用UIModalPresentationCustom呈现样式

Answer 2

modalPresentationStyle代替modalTransitionStyle一个视图控制器是一个正确的答案:)