SwiftUI VStack spacing:无法正常工作

Question

我有一个SwiftUI VStack，它位于一个scrollView，一个几何阅读器和一个NavigationView中，代码如下：

struct RezeptList: View {

    @Environment(\.colorScheme) var colorScheme: ColorScheme
    @EnvironmentObject private var recipeStore: RecipeStore

    @State private var searching = false
    @State private var searchText = ""
    @State private var showingAddRecipeView = false

    var body: some View {
        NavigationView{
            GeometryReader { geo in
                ScrollView {
                    SearchBar(searchText: self.$searchText, isSearching: self.$searching)
                    VStack(spacing: 30) {

                        ForEach(self.recipeStore.recipes.filter{$0.name.hasPrefix(self.searchText) || self.searchText == ""}) {recipe in
                            NavigationLink(destination:
                            RezeptDetail(recipe: recipe).environmentObject(self.recipeStore)) {
                                Card(rezept: recipe,width: geo.size.width - 20)
                            }
                            .buttonStyle(PlainButtonStyle())
                        }

                        .navigationBarItems(trailing: Button(action: {
                            self.showingAddRecipeView = true
                        }){
                            Image(systemName: "square.and.pencil")
                                .foregroundColor(.primary)
                            }
                        .padding()
                        )
                    }
                    .padding(.bottom)
                    .navigationBarTitle("Rezepte")
                    .sheet(isPresented: self.$showingAddRecipeView) {
                        AddRecipeView(isPresented: self.$showingAddRecipeView)
                            .environmentObject(self.recipeStore)
                    }
                }
            }
        }
    }

    init() {
        UINavigationBar.appearance().tintColor = UIColor.label
    }

}

但是不管间距有多大，它看起来都是这样的：Image

但我注意到，当我移动.navigationBarItems修饰符时，它可以工作，但当你点击navigationLink时，应用程序就崩溃了。

Answer 1

SwiftUI有时会在放置一些修饰符时出现奇怪的行为问题。

在你的例子中，如果你将.navigationBarItems移到navigationBarTitle之后，它应该会解决这个问题，你会得到你的VStack间距。

.navigationBarTitle("Rezepte")
.navigationBarItems(trailing: Button(action: {
    self.showingAddRecipeView = true
}, label: {
    Image(systemName: "square.and.pencil")
        .foregroundColor(.primary)
}).padding())

此外，我观察到，让这些与导航相关的修饰符更接近NavigationView要比深入层次结构更好。

示例(基于视图层次结构)：

struct ContentView: View {
    @State var isShowing: Bool = false
    
    var body: some View {
        NavigationView {
            GeometryReader { (geo) in
                ScrollView {
                    VStack(spacing: 60) {
                        ForEach(0...10, id:\.self) { (index) in
                            NavigationLink(destination: Text(String(index))) {
                                Text("Button")
                            }
                        }
                    }
                    .navigationBarTitle("Title")
                    .navigationBarItems(trailing: Button(action: {
                        self.isShowing = true
                    }, label: {
                        Image(systemName: "square.and.pencil")
                    }))
                    .sheet(isPresented: self.$isShowing) {
                        Button(action: {
                            self.isShowing = false
                        }) {
                            Text("Dismiss")
                        }
                    }
                }
            }
        }
    }
}