通过SwiftUI组件的参数传递异步函数

import SwiftUI

struct ContentView: View {
    @State private var isLoading = false
    @State private var data: [String] = []

    var body: some View {
        VStack {
            if isLoading {
                Text("Loading...")
            } else {
                List(data, id: \.self) { item in
                    Text(item)
                }
            }
        }
        .onAppear(perform: loadData)
    }

    func loadData() {
        isLoading = true

        // 异步调用数据请求函数
        fetchData { result in
            switch result {
            case .success(let items):
                data = items
            case .failure(let error):
                print(error)
            }

            isLoading = false
        }
    }

    func fetchData(completion: @escaping (Result<[String], Error>) -> Void) {
        // 模拟异步请求数据的过程
        DispatchQueue.global().asyncAfter(deadline: .now() + 2) {
            let items = ["Item 1", "Item 2", "Item 3"]
            completion(.success(items))
        }
    }
}

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