等到alamofire完成获取请求并制作对象

我在等待一个对象时遇到问题，然后我希望更新我的UI。 如果我运行该函数，它将立即得到索引错误，因为它试图从第一个对象获取一些文本时它还没有…任何可以帮助我的人？

func getMovieData(activeGenreLink: String){ //self.posterLoading.startAnimating() Alamofire.request(activeGenreLink).responseJSON { response in //print(response.request) // original URL request //print(response.response) // HTTP URL response //print(response.data) // server data //print(response.result) // result of response serialization var test = 0 self.movieArray = [] if let json = response.result.value as? Dictionary { if let movies = json["results"] as? [AnyObject]{ for movie in movies{ let movieObject: Movie = Movie() let title = movie["title"] as? String let releaseDate = movie["release_date"] as! String let posterPath = movie["poster_path"] as! String let overView = movie["overview"] as! String let movieId = movie["id"] as! Int let genre_ids = movie["genre_ids"] as! [AnyObject] movieObject.title = title movieObject.movieRelease = releaseDate movieObject.posterPath = posterPath movieObject.overView = overView movieObject.movieId = movieId for genre in genre_ids{//Genre ids, fix this movieObject.movieGenre.append(genre as! Int) } self.movieArray.append(movieObject) }//End of for each movie } } }//End of Json request }//End of getmoviedata 

Answer 1

使用完成块/闭包。

 func getMovieData(activeGenreLink: String,completion : ()->()){ //self.posterLoading.startAnimating() Alamofire.request(activeGenreLink).responseJSON { response in //print(response.request) // original URL request //print(response.response) // HTTP URL response //print(response.data) // server data //print(response.result) // result of response serialization var test = 0 self.movieArray = [] if let json = response.result.value as? Dictionary { if let movies = json["results"] as? [AnyObject]{ for movie in movies{ let movieObject: Movie = Movie() let title = movie["title"] as? String let releaseDate = movie["release_date"] as! String let posterPath = movie["poster_path"] as! String let overView = movie["overview"] as! String let movieId = movie["id"] as! Int let genre_ids = movie["genre_ids"] as! [AnyObject] movieObject.title = title movieObject.movieRelease = releaseDate movieObject.posterPath = posterPath movieObject.overView = overView movieObject.movieId = movieId for genre in genre_ids{//Genre ids, fix this movieObject.movieGenre.append(genre as! Int) } self.movieArray.append(movieObject) }//End of for each movie } } completion() }//End of Json request } 

最后调用这个方法，

 self.getMovieData(activeGenreLink: "your_link_here", completion: { //updateUI }) 

为什么？

因为Alamofire responseJSON是一个异步调用。 当您调用方法getMovieData它会返回而不等待responseJSON完成。 您需要一个完成处理程序来通知VC调用getMovieData来通知它的完成。

因为在主线程上触发了Alamofire responseJSON块，所以您可以直接更新完成块中的UI而无需更改线程。