更改viewModel中@Binding值的最佳方法是什么

Question

@View中的Binding值是从外部获取的，如何控制ViewModel中的值，最佳实践是什么

import SwiftUI
import Combine

struct ContentView: View {
    @State var isPresented = false
    var body: some View {
        VStack {
            Button("show popup") {
                isPresented = true
            }
        }
        .sheet(isPresented: $isPresented) {
            PopupView(isPresented: $isPresented)
        }
    }
}

struct PopupView: View {
    @Binding var isPresented: Bool
    
    @StateObject private var vm = PopupViewModel()
    
    var body: some View {
        Button("dimiss") {
            // isPresented = false
            vm.dismiss()
        }
    }
    
    private class PopupViewModel: ObservableObject {
        func dismiss() {
            // TODO: how to change isPresented
            // how to pass @Binding to VM
        }
    }
}

我尝试在查看时将块传递给vm

onAppear

，然后更改块中的View属性，就像这样

struct PopupView: View {
    @Binding var isPresented: Bool
    
    @StateObject private var vm = PopupViewModel()
    
    var body: some View {
        Button("dimiss") {
            vm.dismiss()
        }
        .onAppear {
            vm.dismissBlock = {
                isPresented = false
            }
        }
    }
    
    private class PopupViewModel: ObservableObject {
        var dismissBlock: (()->Void)?
        func dismiss() {
            dismissBlock?()
        }
    }
}

但这不是最好的方法，有什么好的想法吗？

Answer 1

在代码中，您已经提供了没有理由引入视图模型。您的视图可以提供所有功能。如果您有事实来源，那么您可以添加一个 ObservableObject。保持简单！