Question

所以我有一个ParentView，其中包含一个FilterBar和一个List。看起来像这样：

struct ParentView: View {
    @State var listCellModels: [ListCellModel]

    // Both these vars are passed to the FilterBar and adjusted by the FilterBar
    @State var isEditing: Bool = false
    @State var selectedType: FilterType = .none

    // When selected type is changed, I need to reload the models in the list with the new filter
    private var filteredModels: [ListCellModel] {
        return listCellModels.filter{
            (selectedType.rawValue == 0 || $0.approved.rawValue == selectedType.rawValue)
        }
    }

    var body: some View {
        VStack {
            FilterBar(isEditing: $isEditing, selectedType: $selectedType)

            // All the items in the list are buttons that display a custom view I had
            // this works fine, and when isEditing is changed the view DOES update
            List(filteredModels) { model in
                Button(action: {
                    // Does a thing
                }, label: {
                    ListViewCell(model: model, isEditing: self.$isEditing)
                })
            }
        }
    }
}

“我的过滤器”栏只是一个简单的HStack，带有几个用于修改变量的按钮

struct FilterBar: View {
    @Binding var isEditing: Bool
    @Binding var selectedType: FilterType

    var body: some View {
        HStack(alignment: .center) {
            Button(action: {
                self.selectedType = FilterType.init(rawValue: (self.selectedType.rawValue + 1) % 4)!
            }, label: {
                Text("Filter: \(selectedType.name)")
            }).padding(.top).padding(.leading)

            Spacer()

            Button(action: {
                self.isEditing = !self.isEditing
            }, label: {
                Text(!isEditing ? "Edit" : "Done")
            }).padding(.top).padding(.trailing)
        }
    }
}

当我点击更改isEditing的按钮时，列表中的所有单元格都会更新以显示其“编辑”状态，但是当我点击按钮以更改selectedType时，父视图中的变量确实会更新，因为我在调试器中已经观察到-但是该视图不会重新加载。因此，看起来好像仍在应用旧过滤器。

是否有任何原因为什么更新此@State变量不会重新加载视图？

有没有解决方法？

Answer 1

好吧，这就像...解决方法...但要进行测试，请尝试

FilterBar(isEditing: $isEditing, selectedType: $selectedType)
if selectedType != .none {
   EmptyView()
}

通常，将视图模型引入为ObservableObject并在其中将filteredModels引入为@Published是正确的，因此您的FilterBar更改了该属性，该属性将自动刷新了ParentView。

从@Binding var修改@State var不会刷新SwiftUI中的视图

1 个答案: