List SwiftUI列表正在工作,但选择器不工作
我有这个看法。通过显示数据,列表可以正常工作。选择器不工作。它不显示任何数据。两者使用相同的对象和函数。我不知道选择器不显示数据的原因。我想用选择器。我列出这个列表只是为了确定问题,但我仍然不知道List SwiftUI列表正在工作,但选择器不工作,list,swiftui,picker,List,Swiftui,Picker,我有这个看法。通过显示数据,列表可以正常工作。选择器不工作。它不显示任何数据。两者使用相同的对象和函数。我不知道选择器不显示数据的原因。我想用选择器。我列出这个列表只是为了确定问题,但我仍然不知道 import SwiftUI struct GameListPicker: View { @ObservedObject var gameListViewModel = GameListViewModel() @State private var selectedGameList = "
import SwiftUI
struct GameListPicker: View {
@ObservedObject var gameListViewModel = GameListViewModel()
@State private var selectedGameList = ""
var body: some View {
VStack{
List(gameListViewModel.gameList){gameList in
HStack {
Text(gameList.gameName)
}
}
.onAppear() {self.gameListViewModel.fetchData()}
Picker(selection: $selectedGameList, label: Text("")){
ForEach(gameListViewModel.gameList) { gameList in
Text(gameList.gameName)
}
}
.onAppear() {self.gameListViewModel.fetchData()}}
}
}
这是GameListViewModel
import Foundation
import Firebase
class GameListViewModel: ObservableObject{
@Published var gameList = [GameListModel]()
let db = Firestore.firestore()
func fetchData() {
db.collection("GameData").addSnapshotListener {(querySnapshot, error) in
guard let documents = querySnapshot?.documents else {
print("No documents")
return
}
self.gameList = documents.map { queryDocumentSnapshot -> GameListModel in
let data = queryDocumentSnapshot.data()
let gameName = data["GameName"] as? String ?? ""
return GameListModel(id: gameName, gameName: gameName)
}
}
}
}
这是GameListModel
import Foundation
struct GameListModel: Codable, Hashable,Identifiable {
var id: String
//var id: String = UUID().uuidString
var gameName: String
}
提前感谢您提供的任何帮助
选择器
不是设计为动态的,因此在数据更新时不会刷新,请尝试在数据更改时强制重新生成选择器,如下所示
Picker(selection: $selectedGameList, label: Text("")){
ForEach(gameListViewModel.gameList) { gameList in
Text(gameList.gameName)
}
}.id(gameListViewModel.gameList) // << here !!
Picker(选择:$selectedGameList,标签:Text(“”)){
ForEach(gameListViewModel.gameList){gameList中的gameList
文本(gameList.gameName)
}
}.id(gameListViewModel.gameList)//