SwiftUI:如何在视图中初始化依赖于另一个变量的变量

import SwiftUI

struct ContentView: View {
    @State private var count: Int = 0
    @State private var doubleCount: Int
    
    init() {
        // 初始化依赖于另一个变量的变量
        _doubleCount = State(initialValue: count * 2)
    }
    
    var body: some View {
        VStack {
            Text("Count: \(count)")
            Text("Double Count: \(doubleCount)")
            
            Button(action: {
                count += 1
                doubleCount = count * 2 // 更新依赖的变量
            }) {
                Text("Increment")
            }
        }
    }
}

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