Question

我使用YouTube数据API和Alamofire显示我的YouTube频道视频，并动态更新。这是我的代码：

func getFeedVideo() {        

Alamofire.request("https://www.googleapis.com/youtube/v3/playlists", parameters: parameters, encoding: URLEncoding.default, headers: nil).responseJSON { (response) in

        if let JSON = response.result.value {

            if let dictionary = JSON as? [String: Any] {

                var arrayOfVideos = [Video]()

                for video in dictionary["items"] as! NSArray {
                    //  Create video objects off of the JSON response
                    let videoObj = Video()
                    videoObj.videoID = (video as AnyObject).value(forKeyPath: "snippet.resourceId.videoId") as! String
                    videoObj.videoTitle = (video as AnyObject).value(forKeyPath: "snippet.title") as! String
                    videoObj.videoDescription = (video as AnyObject).value(forKeyPath: "snippet.description") as! String
                    videoObj.videoThumbnailUrl = (video as AnyObject).value(forKeyPath: "snippet.thumbnails.maxres.url") as! String

                    arrayOfVideos.append(videoObj)

                }
                self.videoArray = arrayOfVideos
                if self.delegate != nil {
                    self.delegate!.dataReady()
                }
            }
        }
    }
}

我收到错误

主题1：EXC_BAD_INSTRUCTION

在for video in dictionary["items"] as! NSArray {行。在控制台中，我看到了

fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)

数据显示在UITableView中。关于如何解决这个问题的任何想法？

Answer 1

请不要使用强制类型演员。它可能会导致您的应用崩溃。如果让或保护让我们使用。尝试像那样迭代它

if let dictionary = JSON as? [String: Any] {
var arrayOfVideos = [Video]()
if let playlist = dictionary["items"] as? [Any] {

    for i in 0..<playlist.count {

        let videoObj = Video()
        if let video = playlist[i] as? [String: Any] {
            if let videoId = video["id"] as? String {
                videoObj.videoID = videoId
            }

            if let snippet = video["snippet"] as? [String: Any] {
                if let videoTitle = snippet["title"] as? String {
                    videoObj.videoTitle = videoTitle
                }

                if let videoDescription = snippet["description"] as? String {
                    videoObj.videoDescription = videoDescription
                }
            }

            if let thumbnails = video["thumbnails"] as? [String: Any]{
                if let maxres = thumbnails["maxres"] as? [String: Any] {
                    if let url = maxres["url"] as? String {
                        videoObj.videoThumbnailUrl = url
                    }
                }
            }
            arrayOfVideos.append(videoObj)
        }
    }
}

}

Answer 2

这意味着您没有字典中的项目值，或者您正在不正确地访问它。

Answer 3

你正试图向NSArray施放一股力量。如果dictionary["items"]不是NSArray，这将使您的应用程序崩溃我建议你在循环之前设置一个断点来检查dictionary["items"]的类型。

示例：

guard let items = dictionary["items"] as? NSArray else { return }

使用YouTube Data API和Alamofire时出错

3 个答案: