Hello everyone. I was a building a test app when I encountered this error:
I'm new to indices and am a bit confused by them. Can someone please explain the error to me and show me a possible solution to it? Many thanks!
Here is my code:
import SwiftUI
struct GameView: View { @StateObject var viewModel = GameViewModel()
var body: some View {
ZStack {
GameColor.main.ignoresSafeArea()
VStack {
Text(viewModel.progressText)
.padding()
Spacer()
Text(viewModel.questionText)
.font(.title)
.multilineTextAlignment(.center)
.padding()
Spacer()
Spacer()
HStack {
ForEach(0..<viewModel.answerIndices.count, id: \.self) { index in
AnswerButton(text: viewModel.answerIndices[index]) {
// ForEach(viewModel.answerIndices) { index in
// AnswerButton(text: viewModel.answerText(for: index)) {
viewModel.makeSelectionForCurrentQuestion(at: index)
}
.background(viewModel.colorForButton(at: index))
.disabled(viewModel.selectionWasMade)
}
}
if viewModel.selectionWasMade {
Button(action: viewModel.advanceGameState,
label: {
BottomText(str: "Next")
})
}
}.padding(.bottom)
}
.navigationBarHidden(true)
.background(resultsNavigationLink)
}
private var resultsNavigationLink: some View {
NavigationLink(
destination: ResultsView(viewModel: ResultsViewModel(selectionCount: viewModel.selectionCount, gameStartTime: viewModel.gameStartTime, gameEndTime: Date())),
isActive: .constant(viewModel.gameIsOver),
label: { EmptyView() })
}
}
struct AnswerButton: View { let text: String let onClick: () -> Void var body: some View { Button(action: { onClick() }) { Text(text) } .padding() .border(Color.blue, width: 4) } }
struct ContentView_Previews: PreviewProvider { static var previews: some View { NavigationView { GameView() } } }
(Above is the view; this is the model:
import SwiftUI
class GameViewModel: ObservableObject { @Published var game = Game()
var questionText: String {
game.currentQuestion.questionText
}
var answerIndices: Range<Int> {
game.currentQuestion.possibleAnswers.indices
}
var correctAnswerIndex: Int {
game.currentQuestion.correctAnswerIndex
}
var progressText: String {
"Question \(game.currentQuestionIndex + 1) / \(game.questionCount)"
}
var selectionWasMade: Bool {
game.selections[game.currentQuestion] != nil
}
var selectionCount: (Int, Int) {
game.selectionCount
}
var gameIsOver: Bool {
game.gameIsOver
}
var gameStartTime: Date {
game.startTime
}
func answerText(for index: Int) -> String {
game.currentQuestion.possibleAnswers[index]
}
func advanceGameState() {
game.advanceGameState()
}
func makeSelectionForCurrentQuestion(at index: Int) {
game.makeSelection(at: index)
}
func colorForButton(at buttonIndex: Int) -> Color {
guard let selectedIndex = game.selections[game.currentQuestion], selectedIndex == buttonIndex else { return .clear }
if selectedIndex == correctAnswerIndex {
return .green
} else {
return .red
}
}
}
Thanks for the help in advance!