Question

我手动将另外两个控制器（UINavigationControllerDelegate＆amp; UIImagePickerController）添加到UIViewController，我在添加UIImagePickerController后收到错误消息

Multiple inheritance from classes UIViewController and UIImagePickerController

我现在还不确定如何解释和解决这个问题。

由于此错误，我在使用image.delegate方法并将其设置为self

时也会看到一个错误

Type ViewController does not conform to protocol UIImagePickerControllerDelegate

代码：

class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerController {

    @IBAction func pickImage(sender: UIButton) {

        var image = UIImagePickerController()
        image.delegate = self
        image.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        image.allowsEditing = false

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


    }

Answer 1

您的第一行应该有UIImagePickerControllerDelegate，而不是UIPickerViewController。系统认为你试图让你的控制器继承UIViewController和UIImagePickerController这是不允许的。

Answer 2

我认为swift并不允许多重继承，协议本质上是其他语言所谓的接口，它们用于相同的目的 - 允许安全且有限的多重继承形式。尝试像这样改变它。详情请见here和protocol。

class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate

Swift：类的多重继承错误UIViewController和UIIMagePickerController

2 个答案: