使用 SwiftUI 创建手势以编辑列表项

Question

I am trying to implement a swipe(from left to the right) to edit action using SwiftUI. A delete action(swipe from right to left) and a move item action works perfectly.

I want to open the edit screen on the left to the right guesture

This is my code:

struct TableView : View {
@State var dataSource = DataSource()

var body: some View {
        NavigationView {
            List {
                ForEach(dataSource.pokemons.identified(by: \.id)) { pokemon in
                    Text(pokemon.name) 
                }
                .onDelete(perform: deletePokemon)
                .onMove(perform: movePokemon)
            }
            .navigationBarItems(leading: EditButton(), trailing: Button(action: addPokemon, label: { Text("Add") }))
            .navigationBarTitle(Text("Pokemons"))
        }
}

Answer 1

I don't think it is possible currently.

The best suggestion I have is to roll your own solution by using UITableView via the UIViewRepresentable protocol. That being said, there might be viable open-source solutions out there.

I think hoping for all the UITableView features you may want is risky because List is supposed to be a "generic" type that is supported across various platforms. Some features of UITableView may never come to a List .

This is quick code I typed up, but it gives a simple example of how to create a custom UITableView solution:

RoutineTableView(routines: routineDataSource.routines)
  .trailingSwipeActionsConfiguration {
    let editAction = UIContextualAction(
      style: .normal,
      title: "EDIT"
    ) { (action, sourceView, completionHandler) in

      completionHandler(true)
    }
    editAction.backgroundColor = UIColor.darkGray
    let deleteAction = UIContextualAction(
      style: .destructive,
      title: "DELETE"
    ) { (action, sourceView, completionHandler) in

      completionHandler(true)
    }
    let actions = [deleteAction, editAction]
    let configuration = UISwipeActionsConfiguration(actions: actions)
    return configuration
  }
  .onCellPress {
    print("hi there")
  }
  .navigationBarTitle("Routines")

private class CustomDataSource<SectionType: Hashable, ItemType: Hashable>: UITableViewDiffableDataSource<SectionType, ItemType> {

  override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
    return true
  }
}

struct RoutineTableView: UIViewRepresentable {

  let routines: [Routine]
  private var onCellPress: (() -> Void)? = nil
  private var trailingSwipeActionsConfiguration: (() -> UISwipeActionsConfiguration)? = nil

  init(routines: [Routine]) {
    self.routines = routines
  }

  func makeUIView(
    context: UIViewRepresentableContext<RoutineTableView>
  ) -> UITableView {
    let tableView = UITableView()
    context.coordinator.update(withTableView: tableView)
    return tableView
  }

  func updateUIView(_ uiView: UITableView, context: UIViewRepresentableContext<RoutineTableView>) {
    context.coordinator.update(routines: routines)
  }

  // MARK: - Coordinator

  func makeCoordinator() -> RoutineTableView.Coordinator {
    return Coordinator(self)
  }

  class Coordinator: NSObject, UITableViewDelegate {

    private enum Section {
      case first
    }

    private let view: RoutineTableView
    private var dataSource: UITableViewDiffableDataSource<Section, Routine>?

    init(_ view: RoutineTableView) {
      self.view = view
      super.init()
    }

    func update(withTableView tableView: UITableView) {
      tableView.register(RoutineTableViewCell.self)
      tableView.delegate = self

      let dataSource = CustomDataSource<Section, Routine>(tableView: tableView) { (tableView, indexPath, routine) -> UITableViewCell? in
        let cell: RoutineTableViewCell = tableView.dequeueReusableCell(for: indexPath)
        cell.configure(withRoutine: routine)
        return cell
      }
      self.dataSource = dataSource
    }

    func update(routines: [Routine]) {
      var snapshot = NSDiffableDataSourceSnapshot<Section, Routine>()
      snapshot.appendSections([.first])
      snapshot.appendItems(routines)
      dataSource?.apply(snapshot, animatingDifferences: true)
    }

    // MARK: - <UITableViewDelegate>

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
      view.onCellPress?()
    }

    func tableView(
      _ tableView: UITableView,
      trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath
    ) -> UISwipeActionsConfiguration? {
      return view.trailingSwipeActionsConfiguration?()
    }

  }
}

extension RoutineTableView {

  func onCellPress(
    _ onCellPress: @escaping () -> Void
  ) -> RoutineTableView {
    var view = self
    view.onCellPress = onCellPress
    return view
  }

  func trailingSwipeActionsConfiguration(
    _ trailingSwipeActionsConfiguration: @escaping () -> UISwipeActionsConfiguration
  ) -> RoutineTableView {
    var view = self
    view.trailingSwipeActionsConfiguration = trailingSwipeActionsConfiguration
    return view
  }
}

Answer 2

You have to use EditButton() instead. It enables edit mode for a List component.

Answer 3

Wow! Hmmmm, I'm not sure about using an EditButton() !

I assume you have a list and you want to swipe the row and see a choice to delete right?

All you have to do is implement .onDelete(perform: delete) after the closure for the List. Then, add a function to the structure that defines the delete function in which you handle the closure. Remember that the function will be defined as: func delete (at offsets: IndexSet) {}

Add what I've suggested and compile even without the function body completed (ie add a print() placeholder) and you can see the swipe behaviour for delete.

Answer 4

iOS 15

Starting from iOS 15 you can use swipeActions :

ForEach(dataSource.pokemons.identified(by: \.id)) { pokemon in
    Text(pokemon.name)
}
.swipeActions(edge: .leading) {
    Button("Edit") {
        print("Edit")
    }
    .tint(.blue)
}
.swipeActions(edge: .trailing) {
    Button("Delete", role: .destructive) {
        print("Delete")
    }
    Button("Flag") {
        print("Flag")
    }
    .tint(.orange)
}