我无法更深入地浏览 Swiftui 中的视图

Question

我的项目中有三个视图 - ContentView、SecondView、ThirdView

我想从 contentView 导航到 secondView，从 secondView 导航到 thirdView。

内容视图：-

import SwiftUI

struct ContentView: View {
    @State private var path = NavigationPath()
    
    var body: some View {
        NavigationStack(path: $path) {
            Button {
                path.append("SecondView")
            } label: {
                Text("This is the first view")
                
            }
            .navigationDestination(for: String.self) { view2 in
                if view2 == "SecondView" {
                 SecondView()
                }
            }
        }
    }
}

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

第二视图：-

import SwiftUI

struct SecondView: View {
    @State private var path = NavigationPath()
    var body: some View {
        NavigationStack(path: $path) {
            Button {
                path.append("ThirdView")
            } label: {
                Text("This is the second view")
                
            }
            .navigationDestination(for: String.self) { view2 in
                if view2 == "ThirdView" {
                 ThirdView()
                }
            }
        }
    }
}

struct SecondView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationStack {
            SecondView()
        }
    }
}

第三视图：-

import SwiftUI

struct ThirdView: View {
    var body: some View {
        Text("This is the third view")
    }
}

struct ThirdView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationStack {
            ThirdView()
        }
    }
}

怎么了：-

每当我点击 ContentView 中的“这是第一个视图”按钮时，我都会导航到 SecondView 并自动导航回 contentView。

我想要的是：-

我想从 contentView 导航到 secondView，从 secondView 导航到 thirdView。

Answer 1

您不应该在层次结构中有多个NavigationStack 。 您应该有一个并通过Binding传递path 。

struct ContentView: View {
    @State private var path = NavigationPath()
    
    var body: some View {
        NavigationStack(path: $path) {
            Button {
                path.append("SecondView")
            } label: {
                Text("This is the first view")
                
            }
            .navigationDestination(for: String.self) { view in
                switch view {
                case "SecondView":
                    SecondView(path: $path)
                case "ThirdView":
                    ThirdView()
                default:
                    Text("Unknown")
                }
            }
        }
    }
}

struct SecondView: View {
    @Binding var path: NavigationPath
    var body: some View {
        Button {
            path.append("ThirdView")
        } label: {
            Text("This is the second view")
            
        }
    }
}

struct ThirdView: View {
    var body: some View {
        Text("This is the third view")
    }
}

struct SecondView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationStack {
            SecondView(path: .constant(NavigationPath()))
        }
    }
}