1、新建一个类WxImageDownloader.swift

2、在类中实现代码：

import UIKitimport WeexSDKimport Kingfisherclass WXImageOperation: NSObject, WXImageOperationProtocol {    var task: RetrieveImageDownloadTask?    init(task: RetrieveImageDownloadTask?) {        self.task = task    }        func cancel() {        task?.cancel()    }}class WxImageDownloader: NSObject, WXImgLoaderProtocol {        func downloadImage(withURL url: String!, imageFrame: CGRect, userInfo options: [AnyHashable : Any]! = [:], completed completedBlock: ((UIImage?, Error?, Bool) -> Void)!) -> WXImageOperationProtocol! {        return WXImageOperation.init(task: ImageDownloader.default.downloadImage(with: URL.init(string: url)!, completionHandler: { (image, error, url, data) in            completedBlock?(image, error, data != nil ? true : false)        }))    }}

3、在AppDelegate注册handler：

WXSDKEngine.registerHandler(WxImageDownloader(), with: WXImgLoaderProtocol.self)