从 JSON API 下载 Alamofire

Question

我正在尝试在 api 的标签上设置文本，但似乎该函数甚至没有被调用。请参考下面的sn-p。有什么问题吗？

编辑：typealias DownloadComplete = () -> ()

var date: String = ""

override func viewDidLoad() {
    super.viewDidLoad()

    timeLbl.text = date

    // Do any additional setup after loading the view.
}

func downloadTimeData(completed: @escaping DownloadComplete) {
    //Downloading forecast weather data for TableView
    Alamofire.request(APIURL).responseJSON { response in

        let result = response.result

        if let dict = result.value as? Dictionary<String, AnyObject> {
            if let currentDate = dict["fulldate"] as? String {
                self.date = currentDate
                print(self.date)
                print("xxx")
            }
        }
     completed()
    }
}

Answer 1

我通过 alamofire 文档以更简单、更容易的方式解决了这个问题。

override func viewDidLoad() {
    super.viewDidLoad()

    Alamofire.request(APIURL).responseJSON { response in
        print(response.result)   // result of response serialization
        let result = response.result

        if let dict = result.value as? Dictionary<String, AnyObject> {
            let currentDate = dict["fulldate"] as? String
            self.timeLbl.text = currentDate
            }

    }
}

Answer 2

在您发布的代码中，您没有在任何地方调用downloadTimeData(completed:)。

您可以在viewDidAppear(_:) 中执行此操作，例如：

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    downloadTimeData { 
        // The request has completed
        timeLbl.text = date
    }
}

请注意，您可能需要稍微更改调用，具体取决于DownloadComplete 的定义方式。

Answer 3

您在 viewDidLoad 中的页面加载时立即设置 timeLbl.text，但您没有告诉应用执行其他任何操作。

您必须将 downloadTimeData 移动到 viewDidLoad，并在完成时设置 'timeLbl.text = date'

您必须在拨打电话时设置某种文本占位符或加载程序，因为您不能保证它是即时的。

我们是在设置一个标签吗？还是标签的整个表格视图？

我把一些语法改成了“swiftier”

var date = ""

override func viewDidLoad() {
  super.viewDidLoad()
  //call downloadTimeData here
  downloadTimeData() {
    //once we are in completion, this means internet call finished, so set label now
    self.timeLbl.text = date
  }
}

func downloadTimeData(completed: @escaping DownloadComplete) {
//Downloading forecast weather data for TableView
  Alamofire.request(APIURL).responseJSON { response in
    guard let dict = response.result.value as? [String: AnyObject], let currentDate = dict["full date"] as? String else {
      //handle error here if response fails to give you good data
      completed()
      return
    }
    self.date = currentDate
    print(self.date)
    print("xxx")
    completed()
  }
}