iOS 18.1自定义TextField键盘工具栏在第二个Tab不显示求助

针对iOS 18.1里TabView第二个Tab中自定义数字输入框工具栏不显示的问题，无需依赖NavigationView，可通过以下几种方式解决：

1. 显式绑定焦点状态并关联键盘工具栏 #

自定义MyField时，用@FocusState显式管理输入框的焦点，确保工具栏和键盘强绑定：

struct MyField: View {
    @Binding var value: String
    @FocusState var isFocused: Bool
    
    var body: some View {
        TextField("输入数字", text: $value)
            .keyboardType(.decimalPad)
            .focused($isFocused)
            .toolbar {
                ToolbarItemGroup(placement: .keyboard) {
                    HStack {
                        Button("清除") { value = "" }
                        Spacer()
                        Button("完成") { isFocused = false }
                    }
                }
            }
    }
}

2. 为每个Tab的输入框分配独立焦点状态 #

TabView的子视图状态可能因共享导致冲突，在父视图中为每个Tab的MyField单独维护焦点变量：

struct ParentView: View {
    @State private var selectedTab = 0
    @State private var tab1Value = ""
    @State private var tab2Value = ""
    @FocusState private var tab1Focused: Bool
    @FocusState private var tab2Focused: Bool
    
    var body: some View {
        TabView(selection: $selectedTab) {
            MyField(value: $tab1Value)
                .focused($tab1Focused)
                .tabItem { Label("Tab 1", systemImage: "1.circle") }
                .tag(0)
            
            MyField(value: $tab2Value)
                .focused($tab2Focused)
                .tabItem { Label("Tab 2", systemImage: "2.circle") }
                .tag(1)
        }
    }
}

3. Tab切换时手动刷新状态 #

监听Tab切换事件，强制重置焦点状态，触发工具栏重新加载：

struct ParentView: View {
    @State private var selectedTab = 0
    @State private var tab1Value = ""
    @State private var tab2Value = ""
    @FocusState private var currentFocused: TabFocus?
    
    enum TabFocus { case tab1, tab2 }
    
    var body: some View {
        TabView(selection: $selectedTab) {
            MyField(value: $tab1Value)
                .focused($currentFocused, equals: .tab1)
                .tabItem { Label("Tab 1", systemImage: "1.circle") }
                .tag(0)
            
            MyField(value: $tab2Value)
                .focused($currentFocused, equals: .tab2)
                .tabItem { Label("Tab 2", systemImage: "2.circle") }
                .tag(1)
        }
        .onChange(of: selectedTab) { _ in
            currentFocused = nil
        }
    }
}

关键注意事项 #

• 必须使用ToolbarItemGroup(placement: .keyboard)明确将工具栏绑定到键盘，避免依赖NavigationView的环境上下文
• iOS 18.1中TabView的视图生命周期有细微调整，显式管理焦点能规避系统自动状态管理的bug
• 测试时需验证：每个Tab的输入框获得焦点时工具栏弹出，切换Tab后重新聚焦仍能正常显示

内容的提问来源于stack exchange，提问作者Fab