Mostrando 'UIActivityViewController' en SwiftUI

Quiero permitir que el usuario pueda compartir una ubicación, pero no sé cómo mostrar UIActivityViewController en Swift UI

La implementación básica de UIActivityViewControlleren SwiftUIes

import UIKit
import SwiftUI

struct ActivityViewController: UIViewControllerRepresentable {

    var activityItems: [Any]
    var applicationActivities: [UIActivity]? = nil

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityViewController>) -> UIActivityViewController {
        let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
        return controller
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityViewController>) {}

}

Y así es como se usa.

struct MyView: View {

    @State private var isSharePresented: Bool = false

    var body: some View {
        Button("Share app") {
            self.isSharePresented = true
        }
        .sheet(isPresented: $isSharePresented, onDismiss: {
            print("Dismiss")
        }, content: {
            ActivityViewController(activityItems: [URL(string: "https://www.apple.com")!])
        })
    }
}

Es una cosa de una sola vez actualmente. .sheet lo mostrará como una hoja, pero volver a abrirlo desde la misma vista tendrá datos obsoletos. Esas presentaciones posteriores de la hoja tampoco activarán ningún controlador de finalización. Básicamente, makeUIViewController se llama solo una vez, que es la única forma de obtener los datos para compartir en UIActivityViewController. updateUIViewController no tiene forma de actualizar los datos en sus activityItems o restablecer el controlador porque no son visibles desde una instancia de UIActivityViewController.

Tenga en cuenta que tampoco funciona con UIActivityItemSource o UIActivityItemProvider. Usar esos es aún peor. El valor del marcador de posición no se muestra.

Hice un poco más y decidí que tal vez el problema con mi solución era una hoja que presentaba otra hoja, y cuando una se iba, la otra se quedaba.

Esta forma indirecta de hacer que un ViewController haga la presentación cuando aparece hizo que me funcionara.

class UIActivityViewControllerHost: UIViewController {
    var message = ""
    var completionWithItemsHandler: UIActivityViewController.CompletionWithItemsHandler? = nil

    override func viewDidAppear(_ animated: Bool) {
        share()
    }

    func share() {
        // set up activity view controller
        let textToShare = [ message ]
        let activityViewController = UIActivityViewController(activityItems: textToShare, applicationActivities: nil)

        activityViewController.completionWithItemsHandler = completionWithItemsHandler
        activityViewController.popoverPresentationController?.sourceView = self.view // so that iPads won't crash

        // present the view controller
        self.present(activityViewController, animated: true, completion: nil)
    }
}

struct ActivityViewController: UIViewControllerRepresentable {
    @Binding var text: String
    @Binding var showing: Bool

    func makeUIViewController(context: Context) -> UIActivityViewControllerHost {
        // Create the host and setup the conditions for destroying it
        let result = UIActivityViewControllerHost()

        result.completionWithItemsHandler = { (activityType, completed, returnedItems, error) in
            // To indicate to the hosting view this should be "dismissed"
            self.showing = false
        }

        return result
    }

    func updateUIViewController(_ uiViewController: UIActivityViewControllerHost, context: Context) {
        // Update the text in the hosting controller
        uiViewController.message = text
    }

}

struct ContentView: View {
    @State private var showSheet = false
    @State private var message = "a message"

    var body: some View {
        VStack {
            TextField("what to share", text: $message) Button("Hello World") { self.showSheet = true } if showSheet { ActivityViewController(text: $message, showing: $showSheet)
                    .frame(width: 0, height: 0)
            }

            Spacer()
        }
        .padding()
    }
}

Basado en el de Tikhonov , el siguiente código agregó una solución para asegurarse de que la hoja de actividad se descarte correctamente (si no, posteriormente, la hoja no se presentará).

struct ActivityViewController: UIViewControllerRepresentable {

    var activityItems: [Any]
    var applicationActivities: [UIActivity]? = nil
    @Environment(\.presentationMode) var presentationMode

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityViewController>) -> UIActivityViewController {
        let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
        controller.completionWithItemsHandler = { (activityType, completed, returnedItems, error) in
            self.presentationMode.wrappedValue.dismiss()
        }
        return controller
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityViewController>) {}

}

Puede intentar realizar la migración UIActivityViewControllerde la SwiftUIsiguiente manera:

struct ActivityView: UIViewControllerRepresentable {

    let activityItems: [Any]
    let applicationActivities: [UIActivity]?

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityView>) -> UIActivityViewController {
        return UIActivityViewController(activityItems: activityItems,
                                        applicationActivities: applicationActivities)
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController,
                                context: UIViewControllerRepresentableContext<ActivityView>) {

    }
}

pero la aplicación se bloqueará cuando intente mostrarla.

Probé: Modal, Popovery NavigationButton.

Para probarlo:

struct ContentView: View {
    var body: some Body {
        EmptyView
        .presentation(Modal(ActivityView()))
    }
}

No parece ser utilizable desde SwiftUI.

Lo hice funcionar ahora usando

.sheet(isPresented: $isSheet, content: { ActivityViewController() }

.presentación está obsoleta

Ocupa toda la pantalla al estilo iOS 13.

Quiero sugerir otra implementación que parezca más nativa (media altura de pantalla sin fondo de espacio blanco).

import SwiftUI

struct ActivityView: UIViewControllerRepresentable {
    var activityItems: [Any]
    var applicationActivities: [UIActivity]? = nil
    @Binding var isPresented: Bool

    func makeUIViewController(context: Context) -> ActivityViewWrapper {
        ActivityViewWrapper(activityItems: activityItems, applicationActivities: applicationActivities, isPresented: $isPresented) } func updateUIViewController(_ uiViewController: ActivityViewWrapper, context: Context) { uiViewController.isPresented = $isPresented
        uiViewController.updateState()
    }
}

class ActivityViewWrapper: UIViewController {
    var activityItems: [Any]
    var applicationActivities: [UIActivity]?

    var isPresented: Binding<Bool>

    init(activityItems: [Any], applicationActivities: [UIActivity]? = nil, isPresented: Binding<Bool>) {
        self.activityItems = activityItems
        self.applicationActivities = applicationActivities
        self.isPresented = isPresented
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func didMove(toParent parent: UIViewController?) {
        super.didMove(toParent: parent)
        updateState()
    }

    fileprivate func updateState() {
        guard parent != nil else {return}
        let isActivityPresented = presentedViewController != nil
        if isActivityPresented != isPresented.wrappedValue {
            if !isActivityPresented {
                let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
                controller.completionWithItemsHandler = { (activityType, completed, _, _) in
                    self.isPresented.wrappedValue = false
                }
                present(controller, animated: true, completion: nil)
            }
            else {
                self.presentedViewController?.dismiss(animated: true, completion: nil)
            }
        }
    }
}

struct ActivityViewTest: View {
    @State private var isActivityPresented = false
    var body: some View {
        Button("Preset") {
            self.isActivityPresented = true
        }.background(ActivityView(activityItems: ["Hello, World"], isPresented: $isActivityPresented))
    }
}

struct ActivityView_Previews: PreviewProvider {
    static var previews: some View {
        ActivityViewTest()
    }
}

FWIW: proporciona una ligera mejora a las respuestas que incluye una implementación para UIActivityItemSource. Código simplificado por brevedad, específicamente en torno al retorno predeterminado itemForActivityTypey activityViewControllerPlaceholderItem, siempre deben devolver el mismo tipo.

ActivityViewController

struct ActivityViewController: UIViewControllerRepresentable {

    var activityItems: [Any]
    var shareable : ActivityShareable?
    var applicationActivities: [UIActivity]? = nil

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityViewController>) -> UIActivityViewController {
        let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
        controller.modalPresentationStyle = .automatic
        return controller
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityViewController>) {}

    func makeCoordinator() -> ActivityViewController.Coordinator {
        Coordinator(self.shareable)
    }

    class Coordinator : NSObject, UIActivityItemSource {

        private let shareable : ActivityShareable?

        init(_ shareable: ActivityShareable?) {
            self.shareable = shareable
            super.init()
        }

        func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
            guard let share = self.shareable else { return "" }
            return share.getPlaceholderItem()
        }

        func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
            guard let share = self.shareable else { return "" }
            return share.itemForActivityType(activityType: activityType)
        }

        func activityViewController(_ activityViewController: UIActivityViewController, subjectForActivityType activityType: UIActivity.ActivityType?) -> String {
            guard let share = self.shareable else { return "" }
            return share.subjectForActivityType(activityType: activityType)
        }
    }
}

ActivityShareable

protocol ActivityShareable {

    func getPlaceholderItem() -> Any
    func itemForActivityType(activityType: UIActivity.ActivityType?) -> Any?

    /// Optional
    func subjectForActivityType(activityType: UIActivity.ActivityType?) -> String
}

extension ActivityShareable {

    func subjectForActivityType(activityType: UIActivity.ActivityType?) -> String {
        return ""
    }
}

Puede pasar la referencia ActivityViewControllero el subyacente, UIActivityViewControllerpero eso se siente innecesario.

Ejemplo usando SwiftUIX

Hay una biblioteca llamada SwiftUIX que ya tiene un contenedor para UIActivityViewController. Vea el esqueleto rápido de cómo presentarlo a través del .sheet()cual debe colocarse en algún lugar del var body: some View {}.

import SwiftUIX

/// ...

@State private var showSocialsInviteShareSheet: Bool = false

// ...

.sheet(isPresented: $showSocialsInviteShareSheet, onDismiss: {
    print("Dismiss")
}, content: {
    AppActivityView(activityItems: [URL(string: "https://www.apple.com")!])
})

Puede que no sea recomendable, pero es realmente fácil y tiene dos líneas de código para compartir texto.

Button(action: {
     let shareActivity = UIActivityViewController(activityItems: ["Text To Share"], applicationActivities: nil)
      UIApplication.shared.windows.first?.rootViewController?.present(shareActivity, animated: true, completion: nil)
}) {
    Text("Share")
}

Gracias por las útiles respuestas en este hilo.

Intenté solucionar el stale dataproblema. El problema de no implementar updateUIViewControlleren UIViewControllerRepresentable. SwiftUI llama makeUIViewControllersolo una vez para crear el controlador de vista. El método updateUIViewControlleres responsable de realizar cambios en el controlador de vista según los cambios de la vista SwiftUI.

Como UIActivityViewControllerno permite cambiar activityItemsy applicationActivities, utilicé un controlador de vista de envoltura. UIViewControllerRepresentableactualizará el contenedor y el contenedor creará uno nuevo UIActivityViewControllersegún sea necesario para realizar la actualización.

Debajo de mi código para implementar un botón "compartir" en mi aplicación. El código se prueba en iOS 13.4 beta, que ha corregido varios errores de SwiftUI, no estoy seguro de si funciona en versiones anteriores.

struct Share: View {
    var document: ReaderDocument   // UIDocument subclass
    @State var showShareSheet = false

    var body: some View {
        Button(action: {
            self.document.save(to: self.document.fileURL, for: .forOverwriting) { success in
                self.showShareSheet = true
            }
        }) {
            Image(systemName: "square.and.arrow.up")
        }.popover(isPresented: $showShareSheet) {
            ActivityViewController(activityItems: [ self.document.text, self.document.fileURL,
                                                    UIPrintInfo.printInfo(), self.printFormatter ])
              .frame(minWidth: 320, minHeight: 500)  // necessary for iPad
        }
    }

    var printFormatter: UIPrintFormatter {
        let fontNum = Preferences.shared.readerFontSize.value
        let fontSize = ReaderController.readerFontSizes[fontNum < ReaderController.readerFontSizes.count ? fontNum : 1]
        let printFormatter = UISimpleTextPrintFormatter(text: self.document.text)
        printFormatter.startPage = 0
        printFormatter.perPageContentInsets = UIEdgeInsets(top: 72, left: 72, bottom: 72, right: 72)
        return printFormatter
    }
}

struct ActivityViewController: UIViewControllerRepresentable {

    var activityItems: [Any]
    var applicationActivities: [UIActivity]? = nil
    @Environment(\.presentationMode) var presentationMode

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityViewController>)
        -> WrappedViewController<UIActivityViewController> {
        let controller = WrappedViewController(wrappedController: activityController)
        return controller
    }

    func updateUIViewController(_ uiViewController: WrappedViewController<UIActivityViewController>,
                                context: UIViewControllerRepresentableContext<ActivityViewController>) {
        uiViewController.wrappedController = activityController
    }

    private var activityController: UIActivityViewController {
        let avc = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
        avc.completionWithItemsHandler = { (_, _, _, _) in
            self.presentationMode.wrappedValue.dismiss()
        }
        return avc
    }
}

class WrappedViewController<Controller: UIViewController>: UIViewController {
    var wrappedController: Controller {
        didSet {
            if (wrappedController != oldValue) {
                oldValue.removeFromParent()
                oldValue.view.removeFromSuperview()
                addChild(wrappedController)
                view.addSubview(wrappedController.view)
                wrappedController.view.frame = view.bounds
            }
        }
    }

    init(wrappedController: Controller) {
        self.wrappedController = wrappedController
        super.init(nibName: nil, bundle: nil)
        addChild(wrappedController)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func loadView() {
        super.loadView()
        view.addSubview(wrappedController.view)
        wrappedController.view.frame = view.bounds
    }
}