ios - ViewController中嵌入的ContainerView : Outlets are nil

Question

当我尝试使用函数从其父 View Controller 更新容器 View 内容时。

更新初始 ViewDidLoad 集后。应用程序崩溃。好像所有的Outlet都变成了零

Answer 1

您需要在容器 View 中获取对 View Controller 的引用，然后您应该可以访问其所有导出。为容器 View Controller 的segue分配一个segue标识符，并在调用segue时获取引用。

例如，从父 View Controller 中的按钮更新容器 View Controller 中的标签。

父 View Controller :

import UIKit

class ViewController: UIViewController {
     var containerVC : ContainerVC!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    }

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
    if (segue.identifier == "segueContainer")
        {
            containerVC = segue.destinationViewController as! ContainerVC
        }
    }


@IBAction func butUpdateContainerLabelAction(sender: AnyObject) {
    if containerVC != nil{
           containerVC.lblDemo.text = "some new text"
       }
    }

}

容器 View Controller

class ContainerVC: UIViewController {

@IBOutlet weak var lblDemo: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
   }
}