Select Multiple Items in SwiftUI List

Question

In UIKit you can select multiple rows of a UITableView by using allowsMultipleSelection - can this be done with the List in SwiftUI?

Answer 1

The only way to get multiple selection in SwiftUI right now is by using EditButton. However, that's not the only instance you might want to use multiple selection, and it would probably confuse users if you used EditButton multiple selection when you're not actually trying to edit anything.

I assume what you're really looking for is something like this:

Below is the code I wrote to create this:

struct MultipleSelectionList: View {
    @State var items: [String] = ["Apples", "Oranges", "Bananas", "Pears", "Mangos", "Grapefruit"]
    @State var selections: [String] = []

    var body: some View {
        List {
            ForEach(self.items, id: \.self) { item in
                MultipleSelectionRow(title: item, isSelected: self.selections.contains(item)) {
                    if self.selections.contains(item) {
                        self.selections.removeAll(where: { $0 == item })
                    }
                    else {
                        self.selections.append(item)
                    }
                }
            }
        }
    }
}

struct MultipleSelectionRow: View {
    var title: String
    var isSelected: Bool
    var action: () -> Void

    var body: some View {
        Button(action: self.action) {
            HStack {
                Text(self.title)
                if self.isSelected {
                    Spacer()
                    Image(systemName: "checkmark")
                }
            }
        }
    }
}

Answer 2

First add this to your view

@State var selectedItems = Set<UUID>()

The type of the Set depends on the type you use to id: the items in the ForEach

Next declare the List

List(selection: $selectedItems) {
    ForEach(items, id: \.id) { item in
        Text("\(item.name)")
    }
}

Now whatever you select gets added to the selectedItems Set remember to clear it out after you use it.

Answer 3

I created a custom ToggleStyle as follows:

import SwiftUI


enum Fruit: String, CaseIterable, Hashable {
    case apple = "Apple"
    case orange = "Orange"
    case banana = "Banana"
}

struct ContentView: View {

    @State var fruits = [Bool](repeating: false, count: Fruit.allCases.count)

    var body: some View {
        Form{
            ForEach(0..<fruits.count, id:\.self){i in
                Toggle(isOn: self.$fruits[i]){
                    Text(Fruit.allCases[i].rawValue)
                }.toggleStyle(CheckmarkToggleStyle())
            }
        }
    }
}

struct CheckmarkToggleStyle: ToggleStyle {
    func makeBody(configuration: Self.Configuration) -> some View {
        HStack {
            Button(action: { withAnimation { configuration.$isOn.wrappedValue.toggle() }}){
                HStack{
                    configuration.label.foregroundColor(.primary)
                    Spacer()
                    if configuration.isOn {
                        Image(systemName: "checkmark").foregroundColor(.primary)
                    }
                }
            }
        }
    }
}