1
votes

First SwiftUI project :) I Have a NavLink from a list in a top level view that calls a detail view. it was working until I needed to add a @State var of a Struct into the detail view, now the call parameter list does not match what the compiler expects:

    ZStack {
        VStack {
            NavigationView {
                    List(gList) { gard in
                        NavigationLink(destination:
                            SelectGlyph(catList: gard.category,
                                        firstGlyph: gard.ex1,
                                        descr: gard.title,
                                        selectedGlyph: Glyph() )
                        {

and the detail view starts off:

struct SelectGlyph: View {
    var catList: String
    var firstGlyph: String
    var descr: String
    @State var selectedGlyph:Glyph = Glyph()

    var body: some View {
        ZStack{
            VStack() {
                VStack {
                    VStack {
                        VStack {

and the Glyph Struct is defined as:

struct Glyph: Codable, Identifiable, Equatable {
    var id:String {
        return Gardiner
    }
    var Hieroglyph: String
    var Gardiner: String
    let Unicode: String
    let Description: String
    let Transliteration: String
    let Phonetic: String
    let Notes: String

    init() {
        self.Hieroglyph = ""
        self.Gardiner = ""
        self.Unicode = ""
        self.Description = ""
        self.Transliteration = ""
        self.Phonetic = ""
        self.Notes = ""
    }

    init(Hiero:String, Gard:String, Uni:String, Desc:String, trans:String, phon:String, notes:String) {
        self.Hieroglyph = Hiero
        self.Gardiner = Gard
        self.Unicode = Uni
        self.Description = Desc
        self.Transliteration = trans
        self.Phonetic = phon
        self.Notes = notes
    }
}

The error is in the top level ContentView navLink Destination:

'SelectGlyph.Type' is not convertible to '(String, String, String, Glyph) -> SelectGlyph'

I have tried several variations in the call list and tried to remove the @State wrapper in SelectGlyph, all to no effect. Any help would be appreciated! It would be nice if I knew how to specify a local variable in a View without it being a required argument in the call (Im sure Im missing something here!)

In response to Asperi, I tried the explicit initializer for the SelectGlyph view and still got the same error in the same place:

struct ContentView: View {
    var gList: [GardinerList] = gardinerTest
    var body: some View {
        UINavigationBar.appearance().backgroundColor = .yellow
            return
        ZStack {
            VStack {
                NavigationView {
                        List(gList) { gard in
                            NavigationLink(destination:
                                SelectGlyph(catList: gard.category,  <- Error Here
                                            firstGlyph: gard.ex1,
                                            descr: gard.title,
                                            selectedGlyph: Glyph() )
                            {
                            Text(gard.category)
                                .fontWeight(.bold)
                                .foregroundColor(Color.green)

with the SelectGlyph view now modified to have an explicit init(). I tried specifying selectedGlyph in the init() as _selectedGlyph and as self._selectedGlyph

struct SelectGlyph: View {
    var catList: String
    var firstGlyph: String
    var descr: String
    @State private var selectedGlyph:Glyph = Glyph()

    init(catList: String, firstGlyph: String, descr: String, selectedGlyph:Glyph) {
        self.catList = catList
        self.firstGlyph = firstGlyph
        self.descr = descr
        self._selectedGlyph = State<Glyph>(initialValue: selectedGlyph)
    }

    var body: some View {
        ZStack{
            VStack() {
1

1 Answers

1
votes

It is here

                NavigationLink(destination:
                    SelectGlyph(catList: gard.category,
                                firstGlyph: gard.ex1,
                                descr: gard.title,
                                selectedGlyph: Glyph() )

you need explicit initializer here, like

struct SelectGlyph: View {
    var catList: String
    var firstGlyph: String
    var descr: String

    @State private var selectedGlyph:Glyph // << always keep @State private !!

    init(catList: String, firstGlyph: String, descr: String, selectedGlyph:Glyph) {
        self.catList = catList
        self.firstGlyph = firstGlyph
        self.descr = descr
        _selectedGlyph = State<Glyph>(initialValue: selectedGlyph)
    }

Update: One more. If it is not copy-paste typo then you missed on ')' in NavigationLink

NavigationLink(destination:
    SelectGlyph(catList: gard.category,
                firstGlyph: gard.ex1,
                descr: gard.title,
                selectedGlyph: Glyph() )) // << here !!
{