【SwiftUI】图片选择器 ImagePicker 的包装

由于目前 SwiftUI 还未实现这个组件，所以需要使用 UIkit 的组件包装后在 Swiftui 使用。

import UIKit
import SwiftUI
struct ImagePicker: UIViewControllerRepresentable {

    @Environment(\.presentationMode)
    private var presentationMode

    let sourceType: UIImagePickerController.SourceType
    let onImagePicked: (UIImage) -> Void

    final class Coordinator: NSObject,
    UINavigationControllerDelegate,
    UIImagePickerControllerDelegate {

        @Binding
        private var presentationMode: PresentationMode
        private let sourceType: UIImagePickerController.SourceType
        private let onImagePicked: (UIImage) -> Void

        init(presentationMode: Binding<PresentationMode>,
             sourceType: UIImagePickerController.SourceType,
             onImagePicked: @escaping (UIImage) -> Void) {
            _presentationMode = presentationMode
            self.sourceType = sourceType
            self.onImagePicked = onImagePicked
        }

        func imagePickerController(_ picker: UIImagePickerController,
                                   didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            let uiImage = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
            onImagePicked(uiImage)
            presentationMode.dismiss()

        }

        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            presentationMode.dismiss()
        }

    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(presentationMode: presentationMode,
                           sourceType: sourceType,
                           onImagePicked: onImagePicked)
    }

    func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.sourceType = sourceType
        picker.delegate = context.coordinator
        return picker
    }

    func updateUIViewController(_ uiViewController: UIImagePickerController,
                                context: UIViewControllerRepresentableContext<ImagePicker>) {

    }

}

使用

在 swift 的布局里初始化两个变量，一个控制选择器状态，一个获取选择的图片

 @State var showImagePicker: Bool = false
    @State var image: Image? = nil

.sheet(isPresented: $showImagePicker) {
            ImagePicker(sourceType: .photoLibrary) { image in
                self.image = Image(uiImage: image)
            }
        }

现在 swiftui 还是不完善，希望能够尽快完善一下，不然我还要重头学习 UIKit。