无法使用委托获取数组

Question

在点击我的viewcontrollerA中的一个按钮，我要去viewcontrollerB。我从viewcontrollerB去viewcontrollerC。以及我在viewcontrollerC中的图像数组，我想把它带回到viewcontrollerA。

我就是这样和代表们一起努力实现这一目标的。

class ViewControllerA: UIViewController,ImageAssetsProtocol {

        override func viewWillAppear(_ animated: Bool) {
            var vc = ViewControllerC()
            vc.delegate = self

        }

     //This below method doesn’t get called
     func sendImageAssets(myData: [MyImageAsset]) {
           print(myData)
       }

}
------------------------------------------------------------------------------------------

class ViewControllerC: UIViewController {

protocol ImageAssetsProtocol {
    func sendImageAssets(myData: [MyImageAsset])
}
 weak var imagePreviewDelegate: ImagePreviewDelegate?



//ViewControllerC gets an array of images from ViewcontrollerB. I’m passing that array to ViewControllerA

  override func viewWillDisappear(_ animated: Bool) {

        self.delegate?.sendImageAssets(myData: selectedAssets)
    }

}

但是这样做后，我无法得到ViewControllerA中的图像数组.

Answer 1

以下是您如何进行：

1. 将VC1与ImageAssetsProtocol相结合，并实现了它的sendImageAssets(myData:)方法。

类VC1: UIViewController，ImageAssetsProtocol { func openVC2() { let vc2 =vc2 "VC3") as！VC3 vc2.委托= self } func sendImageAssets(myData: MyImageAsset) { print(myData) }

• In VC2创建一个ImageAssetsProtocol?类型的delegate，并在呈现VC1 VC2时设置vc2.delegate = self

类VC2: UIViewController { var委托: ImageAssetsProtocol？函数openVC3() { let vc3 =vc3 "VC3")！VC3 vc3.agent= self.delegate }

• In VC3创建一个ImageAssetsProtocol?类型的delegate，并在表示VC2 VC3时设置vc3.delegate = self。在sendImageAssets(myData:)中调用委托方法viewWillDisappear(_:)。

类VC3: UIViewController {弱var委托: ImageAssetsProtocol？覆盖func viewWillDisappear(_动画: Bool) { self.delegate?.sendImageAssets(myData: selectedAssets) }