视图控制器以模态方式显示时,未在iOS 9中调用"viewWillTransitionToSize:"

Question

我从另一个提出一个视图控制器:

- (void)showModalView
{
   UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
   MySecViewController *mySecViewController = [storyboard instantiateViewControllerWithIdentifier:@"secController"];
   mySecViewController.delegate = self;
   [self presentViewController:mySecViewController animated:YES completion:nil];
}

然后在呈现中UIViewController,该方法viewWillTransitionToSize:withTransitionCoordinator:被调用iOS 8但不在iOS 9...

谢谢

Answer 1

在当前视图控制器中,如果覆盖viewWillTransitionToSize:withTransitionCoordinator:,请确保调用super.否则,此消息将不会传播到子视图控制器.

对于Objective-C:

- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];

    // Your other code ... 

和斯威夫特:

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)

    // Your other code ...
}

Answer 2

人们已经解释过你必须调用super。我想添加一条信息，可能会帮助那些会遇到我所面临的情况的人。

场景：父级 -> 子级（viewWillTransition 未在子级中调用）

如果您的视图控制器是子视图控制器，则检查是否调用了父视图控制器委托以及是否在那里调用了 super。否则它不会传播到子视图控制器！

class ParentViewController: UIViewController {

    func presentChild() {
        let child = ChildViewController()
        present(child, animated: false, compeltion: nil)
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator) // If this line is missing your child will not get the delegate call in it's viewWillTransition

        // Do something
    }
}

class ChildViewController: UIViewController {

    // This method will not get called if presented from parent view controller and super is not called inside the viewViewWillTransition available there.
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
       super.viewWillTransition(to: size, with: coordinator)

       //Do something
    }
}

PS - 这发生在我身上，因为父代码是由其他人编写的，他们忘记调用 super。