Swift 3游乐场URLSession异步中的UIImage灰度

import UIKit
import CoreImage

// 定义一个函数，用于将UIImage对象转换为灰度图像
func convertToGrayScale(image: UIImage) -> UIImage? {
    guard let ciImage = CIImage(image: image) else {
        return nil
    }
    
    let filter = CIFilter(name: "CIPhotoEffectMono")
    filter?.setValue(ciImage, forKey: kCIInputImageKey)
    
    guard let outputImage = filter?.outputImage else {
        return nil
    }
    
    let context = CIContext(options: nil)
    guard let cgImage = context.createCGImage(outputImage, from: outputImage.extent) else {
        return nil
    }
    
    return UIImage(cgImage: cgImage)
}

// 创建一个URLSession对象
let session = URLSession.shared

// 创建一个URL对象
let url = URL(string: "https://example.com/image.jpg")!

// 创建一个URLSessionDataTask对象来获取网络数据
let task = session.dataTask(with: url) { (data, response, error) in
    if let error = error {
        print("Error: \(error)")
        return
    }
    
    guard let data = data, let image = UIImage(data: data) else {
        print("Invalid image data")
        return
    }
    
    // 将获取的图片转换为灰度图像
    if let grayScaleImage = convertToGrayScale(image: image) {
        // 在这里可以使用灰度图像进行进一步的处理或显示
        // ...
    }
}

// 启动任务
task.resume()