如何使用URLSession从这个URL下载这个图片？

Question

我想从这个URL下载一张图片。

https:/encrypted-tbn0.gstatic.comimages?q=tbn%3AANd9GcSCLjkOCer-xuhkZuvvk3LJYiem4YkAJ869lUXSei5OtZ-SDLWi&usqp=CAU。

使用URL会话。

guard let newURL = url.addingPercentEncoding(withAllowedCharacters:NSCharacterSet.urlQueryAllowed), let url = URL(string: newURL), UIApplication.shared.canOpenURL(url) else {
    // Failed
    return
}

let config = URLSessionConfiguration.default
config.timeoutIntervalForResource = 30
config.timeoutIntervalForRequest = 30
let session = URLSession(configuration: config, delegate: self, delegateQueue: nil)

session.downloadTask(with: url).resume()

我在委托人中得到了回调，并且 状态码为404.

func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

    if let response = downloadTask.response as? HTTPURLResponse, response.statusCode == 404 {
        return
    }

    if let data = try? Data(contentsOf: location), let image = UIImage(data: data) {

    } else {

    }
}

我在这里做错了什么？

Answer 1

一般来说，当你有一个url字符串。addingPercentEncoding 破坏了网址。

你没有显示原来的内容 url (String)很清楚，但这段代码却能如愿以偿。

        let urlString = "https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcSCLjkOCer-xuhkZuvvk3LJYiem4YkAJ869lUXSei5OtZ-SDLWi&usqp=CAU"

        guard let url = URL(string: urlString) else {
            print("Bad url string: \(urlString)")
            return
        }

        let config = URLSessionConfiguration.default
        config.timeoutIntervalForResource = 30
        config.timeoutIntervalForRequest = 30
        let session = URLSession(configuration: config, delegate: self, delegateQueue: nil)

        session.downloadTask(with: url).resume()