iOS15 SwiftUI关闭sheet后跳转的目标View立即被弹出问题

iOS15的SwiftUI存在导航栈状态识别异常的问题：你同时触发sheet关闭和NavigationLink激活两个状态变更时，系统在重绘视图的过程中会误判导航栈的激活状态，导致刚push的C视图被自动pop。你当前代码里在B视图的按钮点击事件中同时修改closeView和showChatView两个绑定状态，正好触发了这个系统bug。

调整状态变更时序：先只关闭sheet，等sheet完全关闭后再触发C视图的push操作，避免两个状态变更同时执行冲突。
具体修改如下：

1. View A 代码调整 #

新增状态标记sheet关闭后是否需要跳转，在sheet的onDismiss回调中执行跳转逻辑：

import SwiftUI

struct A: View {
    @State private var showNewMessage = false
    @State private var showChatView = false
    // 新增状态：标记sheet关闭后是否需要跳转C视图
    @State private var shouldPushChatAfterDismiss = false
    
    var body: some View {
        ZStack(alignment: .bottomTrailing){
            
            NavigationLink(
                destination: C(),
                isActive: $showChatView,
                label: {})
            
            ScrollView {
                VStack(alignment: .leading) {
                    ForEach(1...10, id: \.self){_ in
                        NavigationLink(
                            destination: C(),
                            label: {
                                ChatView()
                            })
                    }
                }
            }
            
            Button(action: {
                showNewMessage = true
            }, label: {
                Image(systemName: "pencil")
                    .resizable()
                    .scaledToFit()
                    .frame(width: 24, height: 24)
            })
            .padding()
            .foregroundColor(Color.white)
            .background(Color.blue)
            .clipShape(Circle())
            .sheet(isPresented: $showNewMessage, onDismiss: {
                // sheet完全关闭后判断是否需要跳转
                if shouldPushChatAfterDismiss {
                    showChatView = true
                    shouldPushChatAfterDismiss = false
                }
            }, content: {
                // 传入新增的状态绑定
                B(shouldPushChat: $shouldPushChatAfterDismiss, closeView: $showNewMessage)
            }).navigationViewStyle(StackNavigationViewStyle())
            
        }
        .padding(.horizontal)
    }
}

2. View B 代码调整 #

按钮点击时只标记跳转状态、关闭sheet，不直接触发跳转：

import SwiftUI

struct B: View {
    @Binding var shouldPushChat: Bool
    @Binding var closeView: Bool
    
    var body: some View {
        Button(action: {
            shouldPushChat = true
            closeView = false
        }, label: {
            Text("Toggle")
        })
    }
}

内容的提问来源于stack exchange，提问作者Jose Ricardo Citerio Alcala