如何在 swiftUI 中选择项目时对选择器添加操作？

Question

我有一个带有特定项目列表（比如添加、编辑、删除）的选择器，在选择特定项目时，我需要移至另一个屏幕。我试过 onTapGuesture() 但是当我调试它时控制不会进入内部。

Answer 1

我找到了 3 种不同的方法来实现这一点。我拍的最后一张。所以，有这么多方法，你可以选择你想要的：

struct PickerOnChange: View {

    private var options = ["add", "edit", "delete"]
    @State private var selectedOption = 0
    @State private var choosed = 0

    var body: some View {

        VStack {

            Picker(selection: $selectedOption.onChange(changeViewWithThirdWay), label: Text("Choose action")) {
                ForEach(0 ..< self.options.count) {
                    Text(self.options[[=10=]]).tag([=10=])
                }
            }.pickerStyle(SegmentedPickerStyle())

            // MARK: first way
            VStack {
                if selectedOption == 0 {
                    Text("add (first way)")
                } else if selectedOption == 1 {
                    Text("edit (first way)")
                } else {
                    Text("delete (first way)")
                }

                Divider()

                // MARK: second way
                ZStack {

                    AddView()
                        .opacity(selectedOption == 0 ? 1 : 0)

                    EditView()
                        .opacity(selectedOption == 1 ? 1 : 0)

                    DeleteView()
                        .opacity(selectedOption == 2 ? 1 : 0)
                }

                Divider()

                // MARK: showing third way
                Text("just to show, how to use third way: \(self.choosed)")

                Spacer()

            }

        }

    }

    func changeViewWithThirdWay(_ newValue: Int) {
        print("will change something in third way with: \(choosed), you can do everything in this function")
        withAnimation {
            choosed = newValue
        }

    }

}

// MARK: the third way
extension Binding {
    func onChange(_ handler: @escaping (Value) -> Void) -> Binding<Value> {
        return Binding(
            get: { self.wrappedValue },
            set: { selection in
                self.wrappedValue = selection
                handler(selection)
        })
    }
}

您将使用代码片段实现此目的：

如何在 swiftUI 中选择项目时对选择器添加操作？

How do I add action on picker on selection of item in swiftUI?

picker

swiftui