Swift和JSON url图像，编辑

import UIKit

func downloadImage(from url: URL, completion: @escaping (UIImage?) -> Void) {
    URLSession.shared.dataTask(with: url) { data, response, error in
        guard let data = data, error == nil else {
            completion(nil)
            return
        }
        
        let image = UIImage(data: data)
        completion(image)
    }.resume()
}

// 使用示例
let imageUrl = URL(string: "https://example.com/image.jpg")!
downloadImage(from: imageUrl) { image in
    if let image = image {
        // 下载成功，可以在这里使用图像
    } else {
        // 下载失败
    }
}

import Foundation

struct Person: Codable {
    let name: String
    let age: Int
}

// 编码为JSON数据
let person = Person(name: "John", age: 30)
let encoder = JSONEncoder()
if let jsonData = try? encoder.encode(person) {
    let jsonString = String(data: jsonData, encoding: .utf8)
    print(jsonString) // 输出：{"name":"John","age":30}
}

// 解码JSON数据
let jsonString = """
    {"name":"John","age":30}
"""
let decoder = JSONDecoder()
if let jsonData = jsonString.data(using: .utf8),
   let decodedPerson = try? decoder.decode(Person.self, from: jsonData) {
    print(decodedPerson) // 输出：Person(name: "John", age: 30)
}