似乎无法创建与CNContactPickerViewController一起使用的UIViewControllerRepresentable。
使用Xcode 11 beta 4，我已经使用其他UIViewController创建了许多其他的UIViewControllerRepresentable，并且效果很好。我尝试更改CNContactPickerViewController的功能以及委托的不同实现。
import SwiftUI
import ContactsUI
// Minimal version
struct LookupContactVCR : UIViewControllerRepresentable {
func makeUIViewController(context: Context) -> CNContactPickerViewController {
let contactPickerVC = CNContactPickerViewController()
contactPickerVC.delegate = context.coordinator
return contactPickerVC
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func updateUIViewController(_ uiViewController: CNContactPickerViewController, context: Context) {}
class Coordinator: NSObject {}
}
extension LookupContactVCR.Coordinator : CNContactPickerDelegate {
func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
print("Chose: \(contact.givenName)")
}
}
#if DEBUG
struct LookupContact_Previews : PreviewProvider {
static var previews: some View {
LookupContactVCR()
}
}
#endif
无错误消息。但是屏幕始终是白色的，什么也没渲染。
答案 0 :(得分：4)
首先，请为此问题提交Bug Report。 其次，此问题有 2个解决方法：
ABPeoplePickerNavigationController，但仍然可以使用。UIViewController上显示CNContactPickerViewController的{{1}}，并将这个新创建的视图控制器与viewWillAppear一起使用。SwiftUIimport SwiftUI
import AddressBookUI
struct PeoplePicker: UIViewControllerRepresentable {
typealias UIViewControllerType = ABPeoplePickerNavigationController
final class Coordinator: NSObject, ABPeoplePickerNavigationControllerDelegate, UINavigationControllerDelegate {
func peoplePickerNavigationController(_ peoplePicker: ABPeoplePickerNavigationController, didSelectPerson person: ABRecord) {
<#selected#>
}
func peoplePickerNavigationControllerDidCancel(_ peoplePicker: ABPeoplePickerNavigationController) {
<#cancelled#>
}
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func makeUIViewController(context: UIViewControllerRepresentableContext<PeoplePicker>) -> PeoplePicker.UIViewControllerType {
let result = UIViewControllerType()
result.delegate = context.coordinator
return result
}
func updateUIViewController(_ uiViewController: PeoplePicker.UIViewControllerType, context: UIViewControllerRepresentableContext<PeoplePicker>) { }
}
import Foundation
import ContactsUI
protocol EmbeddedContactPickerViewControllerDelegate: class {
func embeddedContactPickerViewControllerDidCancel(_ viewController: EmbeddedContactPickerViewController)
func embeddedContactPickerViewController(_ viewController: EmbeddedContactPickerViewController, didSelect contact: CNContact)
}
class EmbeddedContactPickerViewController: UIViewController, CNContactPickerDelegate {
weak var delegate: EmbeddedContactPickerViewControllerDelegate?
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.open(animated: animated)
}
private func open(animated: Bool) {
let viewController = CNContactPickerViewController()
viewController.delegate = self
self.present(viewController, animated: false)
}
func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
self.dismiss(animated: false) {
self.delegate?.embeddedContactPickerViewControllerDidCancel(self)
}
}
func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
self.dismiss(animated: false) {
self.delegate?.embeddedContactPickerViewController(self, didSelect: contact)
}
}
}
答案 1 :(得分：1)
我所做的只是将它包装在一个 NavigationController 中。也许不像arturigor的回答那么干净，但很容易工作。
func makeUIViewController(context: Context) -> some UIViewController {
// needs to be wrapper in another controller. Else isn't displayed
let navController = UINavigationController()
let controller = CNContactPickerViewController()
controller.delegate = delegate
controller.predicateForEnablingContact = enablingPredicate
navController.present(controller, animated: false, completion: nil)
return navController
}
关于问题，它应该如何显示。我只是让它有条件地显示为组内的视图
Group {
Text("Sharing is caring")
if showContactPicker {
ContactPicker(contactType: .email)
}
}
答案 2 :(得分：0)
@youjin 解决方案在带有导航视图的工作表中使用时会出现问题。
例如，首先我展示了一个 .sheet 视图，在我拥有的这个 sheet 视图和 NavigationView 作为子视图中，然后，在所有这些中，我展示了联系人选择器。对于这种情况，当 Contact Picker 关闭时，还要关闭我的工作表视图父级。
我添加了一个 @Environment(\.presentationMode) 变量，并使用 Coordinator 方法将其关闭。在这里查看我的解决方案：
import SwiftUI
import ContactsUI
/**
Presents a CNContactPickerViewController view modally.
- Parameters:
- showPicker: Binding variable for presenting / dismissing the picker VC
- onSelectContact: Use this callback for single contact selection
- onSelectContacts: Use this callback for multiple contact selections
*/
public struct ContactPicker: UIViewControllerRepresentable {
@Environment(\.presentationMode) var presentationMode
@Binding var showPicker: Bool
@State private var viewModel = ContactPickerViewModel()
public var onSelectContact: ((_: CNContact) -> Void)?
public var onSelectContacts: ((_: [CNContact]) -> Void)?
public var onCancel: (() -> Void)?
public init(showPicker: Binding<Bool>, onSelectContact: ((_: CNContact) -> Void)? = nil, onSelectContacts: ((_: [CNContact]) -> Void)? = nil, onCancel: (() -> Void)? = nil) {
self._showPicker = showPicker
self.onSelectContact = onSelectContact
self.onSelectContacts = onSelectContacts
self.onCancel = onCancel
}
public func makeUIViewController(context: UIViewControllerRepresentableContext<ContactPicker>) -> ContactPicker.UIViewControllerType {
let dummy = _DummyViewController()
viewModel.dummy = dummy
return dummy
}
public func updateUIViewController(_ uiViewController: _DummyViewController, context: UIViewControllerRepresentableContext<ContactPicker>) {
guard viewModel.dummy != nil else {
return
}
// able to present when
// 1. no current presented view
// 2. current presented view is being dismissed
let ableToPresent = viewModel.dummy.presentedViewController == nil || viewModel.dummy.presentedViewController?.isBeingDismissed == true
// able to dismiss when
// 1. cncpvc is presented
let ableToDismiss = viewModel.vc != nil
if showPicker && viewModel.vc == nil && ableToPresent {
let pickerVC = CNContactPickerViewController()
pickerVC.delegate = context.coordinator
viewModel.vc = pickerVC
viewModel.dummy.present(pickerVC, animated: true)
} else if !showPicker && ableToDismiss {
// viewModel.dummy.dismiss(animated: true)
self.viewModel.vc = nil
}
}
public func makeCoordinator() -> Coordinator {
if self.onSelectContacts != nil {
return MultipleSelectionCoordinator(self)
} else {
return SingleSelectionCoordinator(self)
}
}
public final class SingleSelectionCoordinator: NSObject, Coordinator {
var parent : ContactPicker
init(_ parent: ContactPicker){
self.parent = parent
}
public func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
parent.showPicker = false
parent.onCancel?()
}
public func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
parent.showPicker = false
parent.onSelectContact?(contact)
}
}
public final class MultipleSelectionCoordinator: NSObject, Coordinator {
var parent : ContactPicker
init(_ parent: ContactPicker){
self.parent = parent
}
public func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
parent.showPicker = false
parent.onCancel?()
parent.presentationMode.wrappedValue.dismiss()
}
public func contactPicker(_ picker: CNContactPickerViewController, didSelect contacts: [CNContact]) {
parent.showPicker = false
parent.onSelectContacts?(contacts)
parent.presentationMode.wrappedValue.dismiss()
}
}
}
class ContactPickerViewModel {
var dummy: _DummyViewController!
var vc: CNContactPickerViewController?
}
public protocol Coordinator: CNContactPickerDelegate {}
public class _DummyViewController: UIViewController {}