如何使用Swift 5从URL获取HTML代码

import Foundation

func fetchHTML(from urlString: String, completion: @escaping (Result<String, Error>) -> Void) {
    guard let url = URL(string: urlString) else {
        completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "Invalid URL"])))
        return
    }

    let task = URLSession.shared.dataTask(with: url) { data, response, error in
        if let error = error {
            completion(.failure(error))
            return
        }

        guard let data = data else {
            completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "No data received"])))
            return
        }

        if let htmlString = String(data: data, encoding: .utf8) {
            completion(.success(htmlString))
        } else {
            completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to convert data to string"])))
        }
    }
    task.resume()
}

// 使用示例
let urlString = "https://www.example.com"
fetchHTML(from: urlString) { result in
    switch result {
    case .success(let html):
        print("HTML: \(html)")
    case .failure(let error):
        print("Error: \(error.localizedDescription)")
    }
}