添加presentationMode后SwiftUI .navigationBarItems .sheet崩溃

Question

我创建了一个 ContentView() 页面，显示应用程序的主要内容。在添加 @Environment(\.presentationMode) varpresentationMode 和与presentationMode相关的函数之前，尾随部分的工作表视图可以正常运行，没有任何问题。现在，主页按钮（前导）运行良好，允许我返回应用程序的菜单页面，但单击另一个按钮（尾随）会立即使应用程序崩溃。奇怪的是 ContentView() 本身在预览模式下运行没有任何问题，但使模拟器崩溃。我尝试了很多方法，但找不到解决此问题的正确方法。

提前致谢。

这是 ContentView() 的部分：

import SwiftUI

struct ContentView: View {

@State var isAddPresented = false
@State var isActive : Bool = false
@Environment(\.presentationMode) var presentationMode
func goBack(){

        self.presentationMode.wrappedValue.dismiss()

    }
var body: some View {
    NavigationView{
            VStack{
                HStack{
                    Text("")
                        .navigationViewStyle(StackNavigationViewStyle())
                        .navigationBarItems(leading:
                                                Button(action: goBack) {
                                                Image("Home") },trailing:
                                                
                                                Button(action: {
                                                self.isAddPresented = true
                                                }) {
                                                Image("Rules_Click")
                                    
                                                            }).padding()
                                                }.sheet(isPresented: $isAddPresented,
                                                onDismiss: { self.isAddPresented = false })
                {RulesView()}.padding(.bottom, 100.0)
            }
    }

这是 HomeView() 的部分：

HStack{
            NavigationLink(destination: ContentView()){
                Image("NormalCards")
                    .resizable(resizingMode: .stretch)
                    .aspectRatio(contentMode: .fit)
                    .navigationTitle("")
                    .navigationBarTitleDisplayMode(.inline)
                    .navigationBarBackButtonHidden(true)
                    .navigationBarHidden(true)     
            }
                
        }

这是 RulesView 部分：

import SwiftUI

struct RulesView: View {
    var body: some View {
        Image("Rules")
            .resizable(resizingMode: .stretch)
            .aspectRatio(contentMode: .fill)
    }
}

struct Rules_Previews: PreviewProvider {
    static var previews: some View {
        RulesView()
    }
}

编辑：

将 .navigationBarItems 更改为工具栏没有改变任何内容。

                            .toolbar{
                            ToolbarItem(placement: .navigationBarLeading) {
                                    Button(action: {
                                        goBack()
                                    }, label: {
                                        Image("Home")
                                    })
                                }
                            ToolbarItem(placement: .navigationBarTrailing) {
                                    Button(action: {
                                        self.isAddPresented = true
                                    }, label: {
                                        Image("Rules_Click")
                                    }).sheet(isPresented: $isAddPresented, onDismiss: { self.isAddPresented = false }) {RulesView()}
                                }
                        }

编辑 Nr.2 ：

这里使用 Text("ExampleText") 而不是 ZStack 效果很好。

struct ContentView: View {
    
    @Environment(\.dismiss) var dismiss
    @State private var isAddPresented = false
    
    func goBack(){
        dismiss() // reset to home view
    }
    
    var body: some View {
        
                ZStack(alignment:.center) {
                                ForEach(Card.data) { card in
                                    CardView(card: card)
                                }
                            }
        
        .navigationBarBackButtonHidden(true)
        
        .toolbar{
            ToolbarItem(placement: .navigationBarLeading) {
                Button(action: {
                    goBack()
                }, label: {
                    Image("Home")
                })
            }
            ToolbarItem(placement: .navigationBarTrailing) {
                Button(action: {
                    self.isAddPresented = true
                }, label: {
                    Image("Rules_Click")
                })
            }
        }
        .sheet(isPresented: $isAddPresented) {
            RulesView()
        }
    }
}

在这里您可以找到有关 ZStack 的 CardView() 信息：

struct CardView: View {
    @State var card: Card
    var body: some View {
        ZStack {
            Image(card.imageName)
        }
        //.background(brownish)
        .offset(x: card.x, y: card.y)
        .rotationEffect(.init(degrees: card.deg))
        .gesture(
            DragGesture()
        
                .onChanged { value in
                    withAnimation(.default){
                        card.x = value.translation.width
                        card.y = value.translation.height
                        card.deg = 7*(value.translation.width > 0 ? 1 : -1)
                    }
                    
                }
                .onEnded { value in
                    withAnimation(.interpolatingSpring(mass: 1.0, stiffness: 50, damping: 8, initialVelocity: 0)) {
                        switch value.translation.width {
                            case 0...100:
                                card.x = 0; card.deg = 0; card.y = 0
                            case let x where x > 100:
                                card.x = 500; card.deg = 12
                            case (-100)...(-1):
                                card.x = 0; card.deg = 0; card.y = 0;
                            case let x where x < -100:
                                card.x = -500; card.deg = -12
                            default: card.x = 0; card.y = 0
                        }
                    }
                }
        )
    }
}

Answer 1

主要是您应该将 .sheet 从 .toolbar 中拉出。
其次，每个模式视图都有自己的dismiss，因此可能两者（NavigationLink 和 Sheet）会相互干扰。
最后你可以使用 @Environment(\.dismiss) var Dismiss 而不是 .presentationMode （它基本上是相同的东西，只是更短）

我重新排序了一点，来到了这个，这对我有用：

struct HomeView: View {

    var body: some View {
        NavigationView {
            VStack{
                NavigationLink {
                    ContentView()
                } label: {
                    Text("NormalCards")
                }
            }
            .navigationBarHidden(true)
        }
    }
}


struct ContentView: View {
    
    @Environment(\.dismiss) var dismiss
    @State private var isAddPresented = false
    
    func goBack(){
        dismiss() // reset to home view
    }
    
    var body: some View {
        
        VStack{
            HStack{
                Text("Example Text")
            }
        }
        .navigationBarBackButtonHidden(true)
        
        .toolbar{
            ToolbarItem(placement: .navigationBarLeading) {
                Button(action: {
                    goBack()
                }, label: {
                    Text("Home")
                })
            }
            ToolbarItem(placement: .navigationBarTrailing) {
                Button(action: {
                    self.isAddPresented = true
                }, label: {
                    Text("Rules")
                })
            }
        }
        .sheet(isPresented: $isAddPresented) {
            RulesView()
        }
    }
}

struct RulesView: View {
    
    @Environment(\.dismiss) var dismiss
    
    var body: some View {
        NavigationView {
            Text("Here are the rules")

                .toolbar {
                    Button("Close") {
                        dismiss()
                    }
                }
        }
    }
}