我想從方法(使用異步調用)返回一個數組(arr
)。我在該方法中實現了completionHandler
,但我無法使用我的方法獲取我的陣列:Cast from '(@escaping ((Array<Any>) -> Void)) ->()' to unrelated type '[[String : Any]]' always fails
CompletionHandler在Swift 3中使用異步調用
我該如何解決這個問題?
這裏是我的代碼:
func dataWithURL(completion: @escaping ((_ result:Array<Any>) -> Void)) {
let urlString = "https://api.unsplash.com/photos/?client_id=71ad401443f49f22556bb6a31c09d62429323491356d2e829b23f8958fd108c4"
let url = URL(string: urlString)!
let urlRequest = URLRequest(url: url)
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
var arr = [[String:String]]()
let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in
// do stuff with response, data & error here
if let statusesArray = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [[String: Any]] {
for item in statusesArray! {
let photos = item["urls"] as? [String: Any]
let photo = photos?["small"] as? String
let myDictionary = [
"name": "test",
"imageURL": photo]
arr.append(myDictionary as! [String : String])
}
print(arr)
completion(arr)
}
})
task.resume()
}
當我想要得到我的數組:
lazy var photos: [Photo] = {
var photos = [Photo]()
// HERE THE ERROR APPEARS
guard let data = self.dataWithURL as? [[String: Any]] else { return photos }
for info in data {
let photo = Photo(info: info)
photos.append(photo)
}
return photos
}()
我想你應該搜索如何調用函數,如何使用閉包,以及如何使用閉包作爲完成塊第一。 –