SwiftUI UIViewControllerRepresentable，Coordinator(self) 是什么意思？

Question

在制作 UIViewControllerRepresentable（在 SwiftUI 中使用 UIKit 组件）时，Coordinator(self) 是什么意思？我对“自我”代表什么感到有点困惑。

import SwiftUI

struct ImagePicker: UIViewControllerRepresentable {
    @Binding var image: UIImage?
    @Environment(\.presentationMode) var presentationMode

    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        var parent: ImagePicker
        
        init(_ parent: ImagePicker) {
            self.parent = parent
        }
        
        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            if let uiImage = info[.originalImage] as? UIImage {
                parent.image = uiImage
            }
            
            parent.presentationMode.wrappedValue.dismiss()
        }
    }
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.delegate = context.coordinator
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {
        
    }
}

Answer 1

self 始终表示“当前实例”。所以当你写...

struct ImagePicker: UIViewControllerRepresentable {
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
}

... self 表示“此 ImagePicker 实例”。

你这样说是因为 Coordinator 的初始值设定项的声明方式：

class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    var parent: ImagePicker
    init(_ parent: ImagePicker) {
        self.parent = parent
    }
}

协调器需要 parent 才能初始化；你正在初始化一个协调器，你告诉它parent应该是谁，即你（即 self，这个 ImagePicker）。

如果这些概念给您带来麻烦，您可能需要研究什么是类型和实例（面向对象编程）and/orSwift 初始化器和初始化是如何表达的。

SwiftUI UIViewControllerRepresentable，Coordinator(self) 是什么意思？

SwiftUI UIViewControllerRepresentable, what does Coordinator(self) mean?

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