nil使用swift 4在两个具有两个不同Bundle的ViewController之间委托(在第二个代码中进行了注释)
这是我的代码:
第一个ViewController:
class FirstVC : UIViewController, MerchantResultObserver{
var secVC = SecondVC()
override func viewDidLoad() {
secVC.delegate = self
let storyboard = UIStoryboard(name: “SecondVC”, bundle: Bundle(identifier: “SecondBundle”))
let controller = storyboard.instantiateInitialViewController()
self.present(controller!, animated: true, completion: nil)
secVC.initSecondVC(data)
}
func Error(data: String) {
print("-------------Error Returned------------- \(data)")
}
func Response(data: String) {
print("-------------Response Returned------------- \(data)")
}
}
第二个ViewController:
public class SecondVC: UIViewController {
public weak var delegate: MerchantResultObserver!
public func initSecondVC(_ data : String){
print(data)
}
@IBAction func sendRequest(_ sender: UIButton) {
delegate?.Response(data: “dataReturnedSuccessfully”) // delegate is nil //
dismiss(animated: true, completion: nil) // returned to FirstVC without returning “dataReturnedSuccessfully” //
}
}
public protocol MerchantResultObserver: class{
func Response(data : String)
func Error(data : String)
}
任何帮助将不胜感激
答案 0 :(得分:2)
var secVC = SecondVC()
和
let storyboard = UIStoryboard(name: “SecondVC”, bundle: Bundle(identifier: “SecondBundle”))
let controller = storyboard.instantiateInitialViewController() as? SecondVC
这两个都是不同的实例。
您可以将委托分配给控制器,例如
controller.delegate = self
它将在First View Controller中调用已实现的委托方法。
完整代码。
let storyboard = UIStoryboard(name: “SecondVC”, bundle: Bundle(identifier: “SecondBundle”))
if let controller = storyboard.instantiateInitialViewController() as? SecondVC {
//Assign Delegate
controller.delegate = self
//It's not init, but an assignment only, as per your code.
controller.initSecondVC(data)
self.present(controller, animated: true, completion: nil)
}
还有一件事情,不要在ViewDidLoad
中显示View。您可以将代码放在某些按钮或延迟方法中。