如何调用我的自定义警报控制器功能以显示在其他视图控制器中？

Question

我已经编写了我的自定义警报视图 controller.But，我在从其他视图调用我的警报控制器时遇到错误 controller.It 显示我在下面描述的错误。

控制台错误

2015-06-15 10:21:50.610 automobile[4197:62165] Warning: Attempt to present <UIAlertController: 0x7d11cf70> on <automobile.LoadingAlertViewController: 0x7bfa55d0> whose view is not in the window hierarchy!

这是我的LoadingAlertViewController

import UIKit

class LoadingAlertViewController: UIAlertController {

var loadingAlertController : UIAlertController!

override func viewDidLoad() {
    super.viewDidLoad()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func displayLoadingAlert() -> UIAlertController {

    var controllerToPresent = viewController
    if controllerToPresent == nil {
            controllerToPresent = self
    }
    //create an alert controller
    loadingAlertController = UIAlertController(title: "Loading...", message: "We are receiving data from network.Please Wait.", preferredStyle: .Alert)

    let indicator = UIActivityIndicatorView()
    indicator.color = UIColor.redColor()
    indicator.setTranslatesAutoresizingMaskIntoConstraints(false)
    loadingAlertController.view.addSubview(indicator)

    let views = ["pending" : loadingAlertController.view, "indicator" : indicator]
    var constraints = NSLayoutConstraint.constraintsWithVisualFormat("V:[indicator]-(7)-|", options: nil, metrics: nil, views: views)
    constraints += NSLayoutConstraint.constraintsWithVisualFormat("H:|[indicator]|", options: nil, metrics: nil, views: views)
    loadingAlertController.view.addConstraints(constraints)

    indicator.userInteractionEnabled = false
    indicator.startAnimating()

    controllerToPresent!.presentViewController(loadingAlertController, animated: true, completion: nil)

    return loadingAlertController
}

func dismissLoadingAlert() -> UIAlertController {
    loadingAlertController.dismissViewControllerAnimated(true, completion: nil)
    return loadingAlertController
}

}

然后我在我的另一个视图控制器上 decalare 这个 LoadingAlertViewController 每次我请求我的 API.

时我都想在其中显示

这是我的ViewController。

import UIKit

class ViewController : UIViewControler{

var loadingAlertController : LoadingAlertController!
var api = MyAPI()

override func viewDidLoad() {

       loadingAlertController = LoadingAlertViewController()

       api.getResults()

       showAlert(true)

}

func showAlert(alert : Bool){

       if alert{

          loadingAlertController.displayLoadingAlert(self)

       }else{

          loadingAlertController.dismissLoadingAlert()

       }

}

有什么帮助吗？拜托？如果有办法，如何从另一个视图调用它controller.Thank你

Answer 1

像这样改变你的方法：

func displayLoadingAlert(viewController: UIViewController?) -> UIAlertController {
    var controllerToPresent = viewController
    if controllerToPresent == nil {
    controllerToPresent = self
}

// Most of your code

controllerToPresent.presentViewController(loadingAlertController, animated: true, completion: nil)

return loadingAlertController
}

然后当您呼叫警报时：

loadingAlertController.displayLoadingAlert(self)

或者：将方法 displayLoadingAlert 重命名为 loadingAlert

删除行：

self.presentViewController(loadingAlertController, animated: true, completion: nil)

然后在 showAlert() 方法内部调用时

let loadingAlertController = loadingAlertController.loadingAlert()
self.presentViewController(loadingAlertController, animated: true, completion: nil)

Answer 2

我看到你做了子类，但是在UIAlertController文档中写着：

The UIAlertController class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.

我建议你不要反对它。如果您需要一些非常自定义的东西，最好使用 UIViewController 并以自定义行为显示。

如何调用我的自定义警报控制器功能以显示在其他视图控制器中？

How to call my custom alert controller function to display in other view controller?

ios

swift

uialertcontroller