ios - 如何发送符合 UIImagePickerControllerDelegate、UINavigationControllerDelegate 的 UIViewController

Question

func openGallery(sender: AnyObject) {
    var imagePicker = UIImagePickerController()
    imagePicker.delegate = sender
    imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
    imagePicker.allowsEditing = true
    sender.navigationController?.presentViewController(imagePicker, animated: true, completion: nil)
}

我想组织我的 UIViewControllers 以将所有图像选择器方法放在一个地方。我想以某种方式编写此方法并使其运行。因为我从多个类访问相机，所以我不想让“发送者”成为特定的 ViewController 类名，这会破坏整个目的。无论我尝试用什么代替“AnyObject”，我都会收到有关 UIImagePickerControllerDelegate 和 UINavigationControllerDelegate 的警告。

我试过这种类型的解决方案也没有用，因为我需要两个代表:

var newSender = sender as UIImagePickerControllerDelegate

我该如何解决这个问题？

Answer 1

您的 Actor 阵容需要的是协议(protocol)构成。

引自“Swift 编程语言”，第 14 页。 545:

You can combine multiple protocols into a single requirement with a protocol composition. Protocol compositions have the form protocol<SomeProtocol, AnotherProtocol>. You can list as many protocols within the pair of angle brackets (<>) as you need, separated by commas.

以下是如何将此概念应用于您的具体案例:

imagePicker.delegate = sender as? protocol<UIImagePickerControllerDelegate, UINavigationControllerDelegate>