How to open the ImagePicker in SwiftUI?

You need to wrap UIImagePickerController in a struct implementing UIViewControllerRepresentable.

For more about UIViewControllerRepresentable, please check this amazing WWDC 2019 talk:

Integrating 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>) {

    }

}

Here’s a simple view to test it:

• The picker is displayed in a sheet
• the selected image appears without any sort of animation, and replaces the Show image picker button

struct ContentView: View {

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

    var body: some View {
        ZStack {
            VStack {
                Button(action: {
                    self.showImagePicker.toggle()
                }) {
                    Text("Show image picker")
                }
                image?.resizable().frame(width: 100, height: 100)
            }
            .sheet(isPresented: $showImagePicker) {
                ImagePicker(sourceType: .photoLibrary) { image in
                    self.image = Image(uiImage: image)
                }
            }
        }
    }
}

I hope this helps as a starting point!

I’m sure Apple will make this easier to do once SwiftUI is out of beta.

Tested on Xcode 11.4

Bugs:

• @JAHelia found a bug on the picker when sourceType is not the camera.
  You won’t be able to drag down the sheet – I haven’t been able to find a solution yet.