如何使用SwiftUI在if语句中创建var

import SwiftUI

struct ContentView: View {
    @State private var isShowingText = false
    
    var body: some View {
        VStack {
            if isShowingText {
                Text("Hello, SwiftUI!")
                    .font(.largeTitle)
                    .foregroundColor(.blue)
            } else {
                Text("SwiftUI is awesome!")
                    .font(.title)
                    .foregroundColor(.green)
            }
            
            Button(action: {
                self.isShowingText.toggle()
            }) {
                Text("Toggle Text")
                    .font(.headline)
                    .foregroundColor(.white)
                    .padding()
                    .background(Color.blue)
                    .cornerRadius(10)
            }
        }
    }
}

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