ios - SwiftUI - 使用 Firebase 实时数据库数据更新视图

Question

为什么我不能Text使用 Firebase 中的适当数据进行更新？我找不到 Firebase Realtime DB 的任何教程，我看到的只是 Firestore。这是我第一次使用iOS开发，请帮助我。

我有以下代码：

struct SceneView: View {
    @Binding var showSceneView: Bool

    var databaseRef : DatabaseReference
    @State var quoteBookDaily : QuoteBook?

    var body: some View {
        ZStack {
            GeometryReader { geomtry in
                ZStack {
                    Text(self.quoteBookDaily?.title ?? "Make sure you are connected to the internet.").font(Font.custom("ShadowsIntoLight", size:30)).multilineTextAlignment(.center).lineSpacing(5).padding()
                    VStack {
                        HStack {
                            Button(action:{self.backPressed()}) {
                                Image("icons8-back-24").renderingMode(.original).resizable().aspectRatio(contentMode: .fit).frame(width: 24, height: 24, alignment: .leading)
                            }.padding()
                            Spacer()
                            Button(action:{self.takeScreenshot()}) {
                                Image("icons8-screenshot-26").renderingMode(.original).resizable().aspectRatio(contentMode: .fit).frame(width: 26, height: 26, alignment: .leading)
                            }.padding()
                        }
                        Spacer()
                    }
                }
            }
        }
    }

    init(showSceneView : Binding<Bool>) {
        self._showSceneView = showSceneView
        self.databaseRef = Database.database().reference()

        self.initDataFromFirebase()
    }

    func backPressed() {
        self.showSceneView = false
    }

    func takeScreenshot() {

    }

    func initDataFromFirebase() {
        let quoteBook = QuoteBook()

        databaseRef.observeSingleEvent(of: .value, with: {(snapshot) in
            let value = snapshot.value as? NSDictionary
            let msg1 = value?["msg1"] as? String ?? " "
            let msg2 = value?["msg2"] as? String ?? " "
            let msg3 = value?["msg3"] as? String ?? " "
            let msg4 = value?["msg4"] as? String ?? " "
            let msg5 = value?["msg5"] as? String ?? " "
            let msg6 = value?["msg6"] as? String ?? " "
            let msg7 = value?["msg7"] as? String ?? " "
            let msg8 = value?["msg8"] as? String ?? " "
            let msg9 = value?["msg9"] as? String ?? " "
            let msg10 = value?["msg10"] as? String ?? " "
            let msg11 = value?["msg11"] as? String ?? " "
            let name = value?["name"] as? String ?? " "

            quoteBook.msg?.append(msg1)
            quoteBook.msg?.append(msg2)
            quoteBook.msg?.append(msg3)
            quoteBook.msg?.append(msg4)
            quoteBook.msg?.append(msg5)
            quoteBook.msg?.append(msg6)
            quoteBook.msg?.append(msg7)
            quoteBook.msg?.append(msg8)
            quoteBook.msg?.append(msg9)
            quoteBook.msg?.append(msg10)
            quoteBook.msg?.append(msg11)
            quoteBook.title = name

        }) { (error: Error?) in
            if let error = error {
                print("Error : \(error).")
            } else {
                self.quoteBookDaily = quoteBook
            }
        }
    }
}

struct SceneView_Previews: PreviewProvider {
    static var previews: some View {
        SceneView(showSceneView : .constant(false))
    }
}

我的QuoteBook班级：

import SwiftUI

class QuoteBook : ObservableObject {
    @Published var msg : [String]? = []
    @Published var title : String?
}

我的 Firebase 数据库看起来像这样： link to screenshot

标签： iosfirebase-realtime-database