当 TextField 位于 .sheet 上时，如何让 @FocusState 属性发挥作用

Question

我有以下简单的代码，它将

Button

放在

View

上，点击时，在

TextField

上呈现

.sheet

：

struct TestView: View
{
    @State private var sheetIsPresented: Bool = false
    @State private var userInput: String = ""
    @FocusState private var textFieldIsFocused: Bool
    
    var body: some View
    {
        Button("Hello")
        {
            self.sheetIsPresented = true
        }
        .buttonStyle(.borderedProminent)
        .sheet(isPresented: self.$sheetIsPresented)
        {
            HStack
            {
                Text("Name:")
                TextField("Enter name", text: self.$userInput).focused(self.$textFieldIsFocused)
                .onChange(of: self.textFieldIsFocused)
                {
                    print("textFieldIsFocused")
                }
            }
        }
    }
}

当

TextField

被激活并且键盘出现时，

.onChange

不会出现，并且“textFieldIsFocused”不会打印到控制台。然而，当我将

TextField

的代码从

.sheet

移到

View

本身时，它工作得很好。当

FocusState

位于

TextField

上时，如何才能使此

.sheet

属性起作用？

Answer 1

当您将工作表内容分解到单独的视图中时，它会起作用：

struct TestViewSheet: View {
    @Binding var userInput: String
    @FocusState private var textFieldIsFocused: Bool

    var body: some View {
        HStack {
            Text("Name:")
            TextField("Enter name", text: $userInput)
                .focused($textFieldIsFocused)
                .onChange(of: textFieldIsFocused) {
                    print("textFieldIsFocused")
                }
        }
    }
}

struct TestView: View {
    @State private var sheetIsPresented: Bool = false
    @State private var userInput: String = ""

    var body: some View {
        Button("Hello") {
            sheetIsPresented = true
        }
        .buttonStyle(.borderedProminent)
        .sheet(isPresented: $sheetIsPresented) {
            TestViewSheet(userInput: $userInput)
        }
    }
}