为什么在模拟器或设备上赢了列表

Question

我已经在Xcode 13.3.1中制作了iPhone/iPad应用程序（带有手表应用程序），但无法弄清楚如何显示列表（我不明白为什么不显示它）。问题既是模拟器和设备上的问题。我已经在代码中标记了列表，

import SwiftUI
struct Period: Identifiable {
    let name: String
    //Day for the period
    let day: Day
    let id = UUID()
}
struct Day: Hashable{
    let weekday: Days
    let schedule: Schedule
}
enum Days: String, CaseIterable, Identifiable{
    var id: String{
        rawValue
    }
    case monday
    case tuesday
    case wednesday
    case thursday
    case friday
}
enum Schedule: String, CaseIterable, Identifiable{
    var id: String{
        rawValue
    }
    case a
    case b
}

我刚刚展示了一个示例以使其更可读。

private var schedule = [
Period(name: "rateing: 3", day: .init(weekday: .monday, schedule: .a)),
Period(name: "form", day: .init(weekday: .monday, schedule: .a)),
Period(name: "Maths", day: .init(weekday: .monday, schedule: .a)),
Period(name: "Break", day: .init(weekday: .monday, schedule: .a)),
Period(name: "Science", day: .init(weekday: .monday, schedule: .a)),
Period(name: "French", day: .init(weekday: .monday, schedule: .a)),
Period(name: "Lunch", day: .init(weekday: .monday, schedule: .a)),
Period(name: "English", day: .init(weekday: .monday, schedule: .a)),
Period(name: "Re", day: .init(weekday: .monday, schedule: .a)),
Period(name: "extra library help", day: .init(weekday: .monday, schedule: .a)),


Period(name: "rateing: 3", day: .init(weekday: .monday, schedule: .b)),
Period(name: "form", day: .init(weekday: .monday, schedule: .b)),
Period(name: "Maths", day: .init(weekday: .monday, schedule: .b)),
Period(name: "Break", day: .init(weekday: .monday, schedule: .b)),
Period(name: "Science", day: .init(weekday: .monday, schedule: .b)),
Period(name: "French", day: .init(weekday: .monday, schedule: .b)),
Period(name: "Lunch", day: .init(weekday: .monday, schedule: .b)),
Period(name: "English", day: .init(weekday: .monday, schedule: .b)),
Period(name: "Re", day: .init(weekday: .monday, schedule: .b)),
Period(name: "extra library duty", day: .init(weekday: .monday, schedule: .b)),
]

如果需要列表的其余部分，则很抱歉，我将提供。

struct ContentView: View {
    
    @State private var current = 5.0
    @State private var minValue = 0.0
    @State private var maxValue = 13.0
    @State private var track = 1.0
    
    let gradient = Gradient(colors: [.green, .yellow, .orange, .red])
    
    @State var re = false
    @State var science = false
    @State var maths = false
    @State var english = false
    @State var history = false
    @State var geography = false
    @State var dt = false
    @State var art = false
    @State var computeing = false
    @State var drama = false
    @State var music = false
    @State var french = false
    @State var german = false
    
    @State var task = 0
    @State var Bre = 0
    @State var Bscience = 0
    @State var Bmaths = 0
    @State var Benglish = 0
    @State var Bhistory = 0
    @State var Bgeography = 0
    @State var Bdt = 0
    @State var Bart = 0
    @State var Bcomputeing = 0
    @State var Bdrama = 0
    @State var Bmusic = 0
    @State var Bfrench = 0
    @State var Bgerman = 0
    
    @State var selectedday: Day? = nil
    @State var selection: Options = .list
    //Contains a filtered list if `selectedday != nil`
    var filteredSchedule: [Period]{
        schedule.filter({ period in
            if let selectedday = selectedday {
                return period.day.weekday == selectedday.weekday && period.day.schedule == selectedday.schedule
            }else{
                return true
            }
        })
    }
    
    
    
    var body: some View {
        VStack {
            ProgressView(value: current/13)
                .padding(.horizontal)
                .frame(height: 20.0)
                
        // homework
            HStack {
                VStack{
                    Toggle("Re", isOn: $re)
                    Toggle("English", isOn: $english)
                    Toggle("Dt", isOn: $dt)
                    Toggle("French", isOn: $french)
                }
                VStack{
                    Toggle("Science", isOn: $science)
                    Toggle("History", isOn: $history)
                    Toggle("Art", isOn: $art)
                    Toggle("German", isOn: $german)
                    Toggle("Drama", isOn: $drama)
                }
                VStack{
                    Toggle("Maths", isOn: $maths)
                    Toggle("Geography", isOn: $geography)
                    Toggle("Computeing", isOn: $computeing)
                    Toggle("Music", isOn: $music)
                }
            }.padding(.horizontal).toggleStyle(.button).foregroundColor(Color.black)
            
                            
            Divider().padding(.vertical)   // homework timetable divide
            
        // timetable
            
            ScrollView{
            

下方的列表

                HStack { 
                    List {
                        Text("Score:")
                        Text("Registration")
                        Text("P1")
                        Text("Break")
                        Text("P2")
                        Text("P3")
                        Text("Lunch")
                        Text("P4")
                        Text("P5")
                        Text("Club")
                    }
                    List(filteredSchedule) {
                        Text($0.name)
                            .font(.body)
                            .padding(.all)
                    }
                }  
            }
        

其余代码的其余部分

            Divider()
                .padding(.vertical)   // timetable - picker divide
            
        // timetable picker
            
            Picker(selection: $selectedday, label: Text("")){
                Text("pick day here").padding(.top).tag(nil as Day?) //Types must match exactly
                ForEach(Days.allCases, id:\.id){ dCase in
                    Group{
                        Text("A - ".capitalized) + Text("\(dCase.rawValue)".capitalized)
                    }
                    .tag(Day(weekday: dCase, schedule: .a) as Day?) //Types must match exactly
                    Group{
                        Text("B - ".capitalized) + Text("\(dCase.rawValue)".capitalized)
                    }
                    .tag(Day(weekday: dCase, schedule: .b) as Day?) //Types must match exactly
                }
            }
            
        }
    }
    
    enum Options{
        case list
        case selection
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}