So boom I'm back again with another probably-stupid question lol. I'm expanding on a helicopter game I found in a YouTube tutorial as a learning exercise. The part I'm stuck on is I'm trying to use core data to allow the user to save their score when they die, and recall those saved scores in a separate view accessible from the game's Home Screen (I'm using ContentView for the Home Screen and a separate GameView for the actual game).
In my data model I define a single entity "Scores", with a single attribute "name".
The Core Data usage in the GameView file returns no errors, but when I try to fetch the data in the view where I want to list the scores, I get the error:
Value of type 'FetchedResults' has no member 'name'
Here go the code for the GameView:
//
// GameView.swift
// Helicopter
//
// Created by Instinct on 10/18/21.
//
import SwiftUI
import AVKit
import CoreData
struct GameView: View{
@State var audioPlayer: AVAudioPlayer!
@State private var heliPosition = CGPoint(x:100, y:100)
@State private var obstPosition = CGPoint(x:1000, y:300)
@State private var flatObstPosition = CGPoint(x:1000, y: 100)
@State var timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()
@State var isPaused = false
@State private var score = 0
@Environment(\.managedObjectContext) var context
// @FetchRequest(entity: Scores.entity(), sortDescriptors: []) var scores: FetchedResults<Scores>
@State public var newScoreValue = ""
@State public var selectedScore: Scores?
let groundPosition = CGPoint(x: 0, y: 1000)
func gravity(){
withAnimation{
self.heliPosition.y = 50
}
}
func obstMove(){
if self.obstPosition.x > 0
{
withAnimation{
self.obstPosition.x -= 20
}
}
else
{
self.obstPosition.x = 1000
self.obstPosition.y = CGFloat.random(in: 0...500)
}
}
func flatObstMove(){
if self.flatObstPosition.x > 0
{
withAnimation{
self.flatObstPosition.x -= 20
}
}
else
{
self.flatObstPosition.x = 1000
self.flatObstPosition.y = CGFloat.random(in: 0...500)
}
}
func pause(){
self.timer.upstream.connect().cancel()
// self.isPaused = true
}
func restart(){
self.timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()
self.obstPosition.x = 1000
self.flatObstPosition.x = 1000
self.heliPosition = CGPoint(x:100, y:100)
self.isPaused = false
self.score = 0
}
func resume(){
self.timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()
self.obstPosition.x = 1000
self.flatObstPosition.x = 1000
self.heliPosition = CGPoint(x:100, y:100)
self.isPaused = false
}
func collisionDetection(){
if abs(heliPosition.x - obstPosition.x) < (25 20) && abs(heliPosition.y - obstPosition.y) < (25 100){
pause()
self.isPaused = true
// self.score = 0
}
if abs(heliPosition.x - flatObstPosition.x) < (25 150) && abs(heliPosition.y - flatObstPosition.y) < (25 30){
pause()
self.isPaused = true
// self.score = 0
}
}
// func startGame(){
// self.timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()
// self.obstPosition.x = 1000
// self.heliPosition = CGPoint(x:100, y:100)
// self.isPaused = false
// self.score = 0
// }
func fallOffDetection(){
if abs(heliPosition.y) > 800{
pause()
self.isPaused = true
}
}
func levelDetection(){
// if self.isPaused == true{
// self.timer.upstream.connect().cancel()
// }
if self.score >= abs(100){
self.timer = Timer.publish(every: 0.1, on: .main, in: .common).autoconnect()
}
else if self.score >= abs(300){
self.timer = Timer.publish(every: 0.05, on: .main, in: .common).autoconnect()
}
else{
// Text("Level 1")
self.timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()
}
}
func save(scores: Scores?) {
if self.selectedScore == nil {
let newScore = Scores(context: self.context)
newScore.name = newScoreValue
try? self.context.save()
}
// else {
// context.performAndWait {
// scores!.name = self.newScoreValue
// try? context.save()
// self.newScoreValue = ""
// self.selectedScore = nil
// }
// }
}
var body: some View {
GeometryReader{ geo in
ZStack{
Helicopter()
.position(self.heliPosition)
.onReceive(self.timer){_ in
self.gravity()
// self.levelDetection()
}
Obstacle()
.position(self.obstPosition)
.onReceive(timer){_ in
// withAnimation{
self.obstMove()
// }
}
FlatObstacle()
.position(self.flatObstPosition)
.onReceive(timer){_ in
self.flatObstMove()
}
Ground()
.position(self.groundPosition)
self.isPaused ? HStack {
Spacer()
Button("restart"){self.restart()}.font(.system(size: 40))
Spacer()
Button("resume"){self.resume()}.font(.system(size:40))
Spacer()
Button("save score"){self.save(scores: selectedScore)}
}: nil
self.isPaused ? Text("your final score is " String(self.score)) .position(x: geo.size.width / 2, y: geo.size.height - 700).foregroundColor(Color.white).font(.system(size: 50)): nil
TextField("\(self.score)", text: $newScoreValue)
.foregroundColor(.white)
.position(x: geo.size.width - 100, y: geo.size.height / 10)
.multilineTextAlignment(.trailing)
// Spacer()
Ground()
// .frame(width: 1000, height: 200)
.foregroundColor(Color.blue)
}
// .onAppear {
// let sound = Bundle.main.path(forResource: "Calboy - All Night Long_2", ofType: "mp3")
// self.audioPlayer = try! AVAudioPlayer( contentsOf: URL(fileURLWithPath: sound!))
//
// }
// }
.frame(width: geo.size.width, height: geo.size.height)
.background(Color.black)
.gesture(
DragGesture()
.onChanged{ value in
withAnimation{
// self.heliPosition.x = heliPosition.x
self.heliPosition.y = value.location.y
}
}
.onEnded{_ in
self.levelDetection()
})
// TapGesture()
// .onEnded{
// withAnimation{
// self.heliPosition.y -= 100
// }
// })
// .onReceive(self.timer){_ in
// self.levelDetection()
// }
}
.onReceive(self.timer) {_ in
self.collisionDetection()
self.score = 1
}
.onReceive(self.timer){_ in
self.fallOffDetection()
// self.score = 0
}
.edgesIgnoringSafeArea(.all)
}
}
struct GameView_Previews: PreviewProvider {
static var previews: some View {
GameView()
}
}
Here go the code for the score list
//
// ViewScores.swift
// Helicopter
//
// Created by Instinct on 10/19/21.
//
import SwiftUI
import CoreData
struct ScoresList: View{
@Environment(\.managedObjectContext) var context
@FetchRequest(entity: Scores.entity(), sortDescriptors: []) var scores: FetchedResults<Scores>
// @State public var newScoreValue = ""
// @State public var selectedScore: Scores?
// @State private var newScoreValue = ""
// @State private var selectedScore: Scores?
// func load(scores: Scores?) {
// if self.selectedScore == nil {
// let newScore = Scores(context: self.context)
// newScore.name = newScoreValue
// try? self.context.()
// }
var body: some View{
List{
ForEach(scores, id: \.self) { score in
Text("\(scores.name!)")
// .onTapGesture {
// self.newScore = savedScores.name
// self.selectedScore = savedScores
// }
}
}
}
}
And just in case it's necessary, here go the code from my AppDelegate file:
//
// AppDelegate.swift
// CoreDataCRUD
//
// Created by Krassimir Iankov on 8/7/20.
// Copyright © 2020 Krassimir Iankov. All rights reserved.
//
import UIKit
import CoreData
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
return true
}
// MARK: UISceneSession Lifecycle
func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
// Called when a new scene session is being created.
// Use this method to select a configuration to create the new scene with.
return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
}
func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
// Called when the user discards a scene session.
// If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
// Use this method to release any resources that were specific to the discarded scenes, as they will not return.
}
// MARK: - Core Data stack
lazy var persistentContainer: NSPersistentContainer = {
/*
The persistent container for the application. This implementation
creates and returns a container, having loaded the store for the
application to it. This property is optional since there are legitimate
error conditions that could cause the creation of the store to fail.
*/
let container = NSPersistentContainer(name: "Scores")
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
/*
Typical reasons for an error here include:
* The parent directory does not exist, cannot be created, or disallows writing.
* The persistent store is not accessible, due to permissions or data protection when the device is locked.
* The device is out of space.
* The store could not be migrated to the current model version.
Check the error message to determine what the actual problem was.
*/
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
return container
}()
// MARK: - Core Data Saving support
func saveContext () {
let context = persistentContainer.viewContext
if context.hasChanges {
do {
try context.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nserror = error as NSError
fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
}
}
}
}
Once again I've scoured the internet and docs and can't figure this out smfh. Any help is greatly appreciated!
CodePudding user response：
Have your Text use the variable from the ForEach
Text("\(score.name!)")
Notice the singular value, the plural value is the array.