在Swift中没有通过委托调用函数

Question

I can't get the app to execute changeCard() after abc() finishes executing. The two functions are in different classes. Here is the code below. Any help is appreciated!

protocol NetworkControllerDelegate {
    func changeCard()
}

class NetworkController {
    var networkControllerDelegate: NetworkControllerDelegate?

    func abc () {
    //do something here
    networkControllerDelegate?.changeCard()
    }
}

class View: UIViewController, NetworkControllerDelegate {
    var networkController = NetworkController()

    func changeCard() {
    //do something here
    networkController.networkControllerDelegate = self
    }
}

I've read all the similar questions on stackoverflow for the past few hours but still can't figure it out. Thanks!

Answer 1

Try moving the following line into viewDidLoad of your view controller so that the delegate is set up prior to use.

networkController.networkControllerDelegate = self

Also, you might want to think about making the networkControllerDelegate variable in NetworkController weak so as to avoid any retain cycles.