如何在SWIFTUI主体视图中使用声明的变量

import SwiftUI

struct ContentView: View {
    // 使用 @State 声明一个变量
    @State private var counter = 0

    var body: some View {
        VStack {
            Text("Counter: \(counter)")
                .padding()
            
            Button(action: {
                // 更新状态
                self.counter += 1
            }) {
                Text("Increment")
                    .padding()
                    .background(Color.blue)
                    .foregroundColor(.white)
                    .cornerRadius(10)
            }
        }
        .padding()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

class CounterModel: ObservableObject {
    @Published var count = 0
}

struct ContentView: View {
    @StateObject private var counterModel = CounterModel()

    var body: some View {
        VStack {
            Text("Counter: \(counterModel.count)")
                .padding()
            
            Button(action: {
                counterModel.count += 1
            }) {
                Text("Increment")
                    .padding()
                    .background(Color.blue)
                    .foregroundColor(.white)
                    .cornerRadius(10)
            }
        }
        .padding()
    }
}