当您将数据添加到Firestore时，屏幕将自动转换

Question

我正在使用Firestore和Swift开发iOS应用。

该应用是用于注册您喜欢的电影的应用。

该屏幕包含：

• 收藏的电影列表
• 所有电影列表
• 视频详细信息屏幕

您可以使用下面的代码将电影添加到收藏夹。

从“ MovieSearchView”转到“ MovieDetailView”，然后单击“添加”按钮。

然后，由于某种原因，它将自动返回到“电影搜索视图”。

即使按下“添加”按钮，如何仍可以停留在“ MovieDetailView”中？

谢谢。

import SwiftUI
import FirebaseFirestore
import Foundation

struct FavoriteMovieListView: View {
    @ObservedObject var favoriteMoviesFetcher = FavoriteMoviesFetcher()
    @State private var modalPresented: Bool = false

    var body: some View {
      VStack {
            Button(action: {
                self.modalPresented.toggle()
            }) {
                Text("Search")
            }
            .sheet(isPresented: self.$modalPresented) {
                MovieSearchView(onDismiss: {
                    self.modalPresented = false
                })
            }

            List(self.favoriteMoviesFetcher.data) { movie in
                Text(movie.title)
            }
        }
    }
}

struct MovieSearchView: View {
    @ObservedObject var allMovieFetcher = AllMovieFetcher()
    var onDismiss: () -> ()

    var body: some View {
        NavigationView {
            List(allMovieFetcher.data) { movie in
                NavigationLink(
                    destination: MovieDetailView(
                        movie: movie
                    )
                ) {
                    Text(movie.title)
                }
            }
        }
    }
}

struct MovieDetailView: View {
    @State var movie: MovieModel

    var body: some View {
        Button(action: {
            FavoriteMoviesService().addMovie(movie: self.movie)
        }) {
            Text("Add")
        }
    }
}

class FavoriteMovieFetcher: ObservableObject {
    @Published var data: [MovieModel] = []

    private var db: Firestore!
    private var uid: String

    init() {
        db = Firestore.firestore()
        uid = UserDefaults.standard.object(forKey: "userUid") as! String

        fetchData()
    }

    private func fetchData() {
        self.db.collection("favoriteMovies/\(uid)/movies").addSnapshotListener { querySnapshot, error in

            guard let snapshot = querySnapshot else {
                print("Error fetching snapshots: \(error!)")
                return
            }

            snapshot.documentChanges.forEach { diff in
                if (diff.type == .added) {
                    self.data.append(MovieModel(
                        movieId: diff.document.documentID,
                        title: diff.document.data()["title"]as! String
                    ))
                } else if (diff.type == .modified) {

                } else if (diff.type == .removed) {
                    self.data = self.data.filter { $0.movieId != diff.document.documentID }
                }
            }

            self.isLoading = false
        }
    }
}

class AllMovieFetcher: ObservableObject {
    @Published var data: [MovieModel] = []
    private var db: Firestore!

    init() {
        db = Firestore.firestore()
        fetchData()
    }

    private func fetchData() {
        self.db.collection("movies").getDocuments { (snaps, err) in
            if let err = err {
                print("Error getting documents: \(err)")
            }

            guard let snaps = snaps else { return }

            for document in snaps.documents {
                    self.data.append(
                        MovieModel(
                            movieId: document.documentID,
                            title: document.data()["title"]as! String
                        )
                    )
            }
        }
    }
}

class FavoriteMoviesService: ObservableObject {
    private var db: Firestore!
    private var uid: String

    init() {
        db = Firestore.firestore()
        uid = UserDefaults.standard.object(forKey: "userUid") as! String
    }

    func addMovie(movie: MovieModel) {
        self.db.collection("favoriteMovies/\(uid)/movies").document(movie.movieId).setData([
            "title": movie.title
        ]) { err in
            if let err = err {
                print("Error adding document: \(err)")
            } else {

            }
        }
    }
}

struct MovieModel: Identifiable {
    var id = UUID()
    var movieId: String
    var title: String
}