我有一个ObservableObject类,Model0
其中有一个Published
object nested
。该nested
对象表示递归树结构。我希望能够更新树结构并适当更新UI。但是,在下面的代码中,当我更新nested
对象的子对象时,UI不会更新,我假定是因为对的引用nested
未更改。每当我更改nested
树形结构中的任何对象时,如何更新UI ?
class Nested: Identifiable {
var id: UUID = UUID()
var name: String
var children:[Nested]
init(name: String, children:[Nested]) {
self.children = children
self.name = name
}
}
class Model0 : ObservableObject {
@Published var nested: Nested
init(nested: Nested) {
self.nested = nested
}
func update() {
nested.children[0] = Nested(name:"New", children: [])
}
}
struct NestedView: View {
var nested: Nested
var body: some View {
VStack {
Text(nested.name)
ForEach(nested.children) { c in
NestedView(nested: c)
}
}
}
}
struct Test: View {
@ObservedObject var model: Model0 = Model0(nested: Nested(name: "Parent" ,children: [Nested(name: "Child", children: [])]))
var body: some View {
VStack {
Button(action: {
self.model.update()
}) {
Text("Update")
}
NestedView(nested: model.nested)
}
}
}
如果决定创建引用类型的模型,则需要使所有模型都可观察,因此每个级别都可以更新相应的视图。并且,当然,每个级别模型都有单独的视图。
考虑到以上,这是一个解决方案。已通过Xcode 12 / iOS 14测试。
仅修改部分:
class Nested: ObservableObject, Identifiable {
var id: UUID = UUID()
@Published var name: String
@Published var children:[Nested]
init(name: String, children:[Nested]) {
self.children = children
self.name = name
}
}
struct NestedView: View {
@ObservedObject var nested: Nested
var body: some View {
VStack {
Text(nested.name)
ForEach(nested.children) { c in
NestedView(nested: c)
}
}
}
}
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