ios - 嵌入式@Binding 不会更改值

Question

关注 this cheat sheet我试图找出 SwiftUI 中的数据流。所以:

Use @Binding when your view needs to mutate a property owned by an ancestor view, or owned by an observable object that an ancestor has a reference to.

这正是我需要的，所以我的嵌入式模型是:

class SimpleModel: Identifiable, ObservableObject {
    @Published var values: [String] = []

    init(values: [String] = []) {
        self.values = values
    }
}

我的 View 有两个字段:

struct SimpleModelView: View {
    @Binding var model: SimpleModel
    @Binding var strings: [String]

    var body: some View {
        VStack {
            HStack {
                Text(self.strings[0])
                TextField("name", text: self.$strings[0])
            }
            HStack {
                Text(self.model.values[0])
                EmbeddedView(strings: self.$model.values)
            }
        }
    }
}

struct EmbeddedView: View {
    @Binding var strings: [String]

    var body: some View {
        VStack {
            TextField("name", text: self.$strings[0])
        }
    }
}

所以我希望 View 会改变 Text当输入字段发生变化时。它适用于 [String]但不适用于嵌入式 @Binding 对象:

为什么它的行为不同？

Answer 1

发布属性(property)

class SimpleModel: Identifiable, ObservableObject {
    @Published var values: [String] = []

和 model观察到的

struct SimpleModelView: View {
    @ObservedObject var model: SimpleModel

注意:这个方向 - 如果你引入了 ObservableObject那么对应的 View 应该有 ObservedObject包装器来观察该可观察对象的已发布属性的变化。