Swiftui-从外部设置了Textfield的焦点

Question

我创建了一个自定义textfield来显示和编辑我的应用程序中的项目标题。当用户创建一个新项目时，我想将此textfield自动.onappear自动关注，因此可以立即输入标题。对于现有项目，TextField不应集中精力。

这样做的唯一方法是在codexfield之外保存@State，如下示例吗？对我来说，似乎有一种更优雅的方法可以实现这一目标，而没有创建另一个@State。

这是一些简化的示例代码：

struct ContentView: View {
    @State var text: String = "Text"
    @State var focusOnAppear = false
    @State var itemID = ""

    var body: some View {

        VStack {
            Button("+ New item") {
                focusOnAppear = true
                itemID = "0"
            }
            Button("Existing item"){
                focusOnAppear = false
                itemID = "1"
            }
            Button("Another existing item"){
                focusOnAppear = false
                itemID = "2"
            }
        }

        CustomTextField($text, focusOnAppear: focusOnAppear)
            .frame(width: 200, height: 44)
            .id(itemID)
    }
}

struct CustomTextField: View {

    @Binding private var text: String
    @FocusState var isFocused: Bool

    var focusOnAppear = false

    init(_ text: Binding<String>, focusOnAppear: Bool) {
        self._text = text
        self.focusOnAppear = focusOnAppear
    }

    var body: some View {
        TextField("", text: $text)
            .focused($isFocused)
            .foregroundColor(isFocused ? .red : .primary)
            .border(Color.gray)
            .onAppear {
                if focusOnAppear {
                    DispatchQueue.main.asyncAfter(deadline: .now()+0.5) {
                        isFocused = true
                    }
                }
            }
    }
}