在 UIContentView 中呈现视图控制器

Question

我的页面ViewController(ABC) 位于根目录ViewController，页面ViewController 包含ViewController(PQR)，其中包含ContentView。我想展示 ViewController 但它说的是

Warning: Attempt to present XYZ: 0x17ee0730 on ABC: 0x17e67dc0 whose view is not in the window hierarchy!

我想在哪个控制器上显示视图控制器

Answer 1

很高兴您的问题得到解决。如果您想从视图控制器以外的任何 UIView 显示警报，这会有所帮助。

此方法获取顶视图控制器，以便您可以从中显示警报：

func currentTopViewController() -> UIViewController{

    var topVC: UIViewController? = UIApplication.shared.delegate?.window??.rootViewController

    while ((topVC?.presentedViewController) != nil) {

        topVC = topVC?.presentedViewController

    }

    return topVC!

}

func showAlert() { // This presents your alert from the received view controller object

    let alertController: UIAlertController = UIAlertController.init(title: "title", message: "message", preferredStyle: .alert)

    let alertAction = UIAlertAction.init(title: "OK", style: .default) { (UIAlertAction) in
            //Your action    
    }

    alertController.addAction(alertAction)

    currentTopViewController().present(alertController, animated: true, completion: nil)

}

在 UIContentView 中呈现视图控制器

present view controller in UIContentView

objective-c

ios

presentviewcontroller