SwiftUI+Firestore 中的多选列表

Question

我正在尝试从 Firestore 加载集合列表，并让它们可以单独选择。我将它设置在从 Firestore 中拉入列表的位置，但如果我选择一个，它会选择全部。另外，我如何将这个数组拉到按钮的 VStack 中而不是列表中？在我的选择屏幕中，此列表有点位于页面中间，我宁愿使用按钮而不是列表，因为列表组件的大小不是动态的。

感谢帮助，代码如下！

import SwiftUI

struct FirestoreTest: View {
    
    @ObservedObject private var viewModel = TriggersViewModel()
    @State private var isSelected = false
    
    var body: some View {
        
        List(viewModel.triggers) { trigger in
            Button(action: { self.isSelected.toggle() }) {
                HStack {
                    if self.isSelected {
                    Text(trigger.name)
                        .foregroundColor(.white)
                        .font(.system(size: 16, weight: .bold))

                        Spacer()
                        Image(systemName: "checkmark")
                            .foregroundColor(Color(.systemPink))
                            .font(.system(size: 16))
                    } else {
                        Text(trigger.name)
                            .foregroundColor(Color(.systemGray))
                            .font(.system(size: 16))
                    }
                }
                .padding(.vertical, 10)
            }
        }
        .onAppear() {
            self.viewModel.fetchData()
        }
        
    }
}

TriggerViewModel.swift

import SwiftUI
import FirebaseFirestore

class TriggersViewModel: ObservableObject {
    
    @Published var triggers = [Trigger]()
    
    private var db = Firestore.firestore()
    
    func fetchData() {
        db.collection("triggers").order(by: "name").addSnapshotListener { (querySnapshot, error) in
            guard let documents = querySnapshot?.documents else {
                print("No Documents")
                return
            }
            
                self.triggers = documents.map { (queryDocumentSnapshot) -> Trigger in
                let data = queryDocumentSnapshot.data()
                
                let name = data["name"] as? String ?? ""
                
                return Trigger(name: name)
                
            }
            
        }
    }
}

Trigger.swift

import SwiftUI

struct Trigger: Identifiable {
    var id: String = UUID().uuidString
    var name: String
}

Answer 1

您需要将isSelected 移动到模型中，并将ForEach 用于VStack。

这是可能的解决方案：

struct Trigger: Identifiable {
    var id: String = UUID().uuidString
    var name: String
    var isSelected = false
}

现在您可以删除@State private var isSelected = false，并且

VStack {
    ForEach(viewModel.triggers.indices, id: \.self) { i in
        Button(action: { viewModel.triggers[i].isSelected.toggle() }) {
            HStack {
                if viewModel.triggers[i].isSelected {
                Text(viewModel.triggers[i].name)
                    .foregroundColor(.white)
                    .font(.system(size: 16, weight: .bold))

                    Spacer()
                    Image(systemName: "checkmark")
                        .foregroundColor(Color(.systemPink))
                        .font(.system(size: 16))
                } else {
                    Text(viewModel.triggers[i].name)
                        .foregroundColor(Color(.systemGray))
                        .font(.system(size: 16))
                }
            }
            .padding(.vertical, 10)
        }
    }
}