SwiftUI Nested NavigationView navigationBar消失

Question

我有三个 ListView 。结构 MainMenuView: 查看 { @EnvironmentObject var 数据模型:DM

var body: some View {

    return NavigationView{
        List {
            Matchup()
            GameSettings()
            EnteringGame()
        }
    }
}

内部匹配()

struct Matchup: View {
@EnvironmentObject var dataModel: DM    

var body: some View {
    Section(header: Text("MATCH-UP")
        .fontWeight(.heavy)
        .foregroundColor(Color("TPLightGrey"))
    ) {
        NavigationLink(destination: TrendSingleSelect(
            title: .constant("TEAM"),
            col: .constant(self.dataModel.queryColumnTeam1),
            items: .constant(self.dataModel.team1Values) ,
            selection: self.$dataModel.team1ListValue
        )) {
            HStack {
                Text("TEAM")
                Spacer()
                if dataModel.team1ListValue.count == 0 {
                    Text("IS ANY").foregroundColor(Color("TPLightGrey"))
                } else {
                    Text( self.dataModel.team1ListValue.joined(separator: ", ")).foregroundColor(Color("TPOrange"))
                }
            }
        }


    }
    .listRowBackground(Color("TPDarkGrey"))
    .font(.system(size: 14))
    .navigationBarTitle("", displayMode: .inline)
    .navigationBarHidden(true)
}

请注意我隐藏了 NavBar。我想在用户点击一行时推送导航。:这是最终 View :

var body: some View {

    return VStack  {

        List {
            ForEach(self.items, id: \.self) { item in
                SingleSelectionRow(title: item, isSelected: self.selection.contains(item)) {

                    if self.selection.contains(item) {
                        self.selection = []
                    }
                    else {
                        self.selection = [item]

                    }
                    self.queryCallback()
                }
                .listRowBackground(Color("TPDarkGrey"))
            }//ForEach
        }//list
            .font(.system(size: 14))
    }

    .navigationBarHidden(false)
    .navigationBarTitle(title)
    .navigationBarItems(trailing:
        Button(action: {
               // Actions
                self.reset()
           }, label: {
            Text("Clear")
            }
        )
    )

}

发生的事情是:当我点击卖出时，我插入了那个部分。但是，当它插入时，我看到了导航栏，然后它就折叠起来了。但是，当我点击 View 中的任何内容以触发 View 重新加载时，它就会显示出来。

是什么导致导航栏崩溃？

Answer 1

在 MatchupView 中尝试这段代码:

struct Matchup: View {
@EnvironmentObject var dataModel: DM    

var body: some View {
NavigationView {            // attention hear************
    Section(header: Text("MATCH-UP")
        .fontWeight(.heavy)
        .foregroundColor(Color("TPLightGrey"))
    ) {
        NavigationLink(destination: TrendSingleSelect(
            title: .constant("TEAM"),
            col: .constant(self.dataModel.queryColumnTeam1),
            items: .constant(self.dataModel.team1Values) ,
            selection: self.$dataModel.team1ListValue
        )) {
            HStack {
                Text("TEAM")
                Spacer()
                if dataModel.team1ListValue.count == 0 {
                    Text("IS ANY").foregroundColor(Color("TPLightGrey"))
                } else {
                    Text( self.dataModel.team1ListValue.joined(separator: ", ")).foregroundColor(Color("TPOrange"))
                }
            }
        }


    }
    .listRowBackground(Color("TPDarkGrey"))
    .font(.system(size: 14))
}                // attention hear************
    .navigationBarTitle("", displayMode: .inline)
    .navigationBarHidden(true)
}