ios - 解析 JSON 它在 Swift 中不起作用

Question

我正在创建一个简单的应用程序，使用 SWAPI 显示《星球大战》中每个角色的详细信息。现在我正在尝试获取物种，但 Xcode 告诉我在尝试打印 _species 时解开可选值时发现了 nil。代码如下:

func DownlaodCompleted(complete: DownloadComplete) {
    let url = NSURL(string: _urlperson)!
    Alamofire.request(.GET, url).responseJSON { (response: Response<AnyObject, NSError>) -> Void in
        let result = response.result

        if let dict = result.value as? Dictionary<String, AnyObject> {

            if let height = dict["height"] as? String {
                self._height = height

            }

            if let gender = dict["gender"] as? String {
                self._gender = gender
            }

            if let birthYear = dict["birth_year"] as? String {
                self._birthYear = birthYear
            }

            if let species = dict["species"] as? [Dictionary<String, String>] {
                let urlSpecies = NSURL(string: self._urlSpecies)!
                Alamofire.request(.GET, urlSpecies).responseJSON(completionHandler: { (response2: Response<AnyObject, NSError>) -> Void in
                    let result = response2.result

                    if let speciesDict = result.value as? Dictionary<String, AnyObject> {
                        if let name = speciesDict["name"] as? String {
                            self._species = name
                        }
                    }
                })

            }
            print(self._species)
            print(self._height)
        }
    }
}

这里是常量类:

let URL_BASE = "http://swapi.co"
let URL_PEOPLE = "/api/people/"
let URL_SPECIES = "/api/species/1/"

typealias DownloadComplete = () ->  ()

Answer 1

这是我在创建空的“单 View 项目”并将 2 个“pod”Alamofire 和 SwiftyJSON 添加到项目后使用的示例代码。

示例代码包含您的一个网址和另一个站点的注释掉的网址。

import UIKit
import Alamofire
import SwiftyJSON // No such module "SwiftyJSON"

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
    @IBOutlet var tableView: UITableView!
    var arrResults = [[String:AnyObject]]() //Array of dictionary

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.frame = CGRect(x: 0, y: 0, width: 320, height: 480)
        self.tableView = UITableView(frame:self.view!.frame)
        self.tableView!.delegate = self
        self.tableView!.dataSource = self
        self.tableView!.registerClass(UITableViewCell.self, forCellReuseIdentifier: "jsonCell")
        self.view?.addSubview(self.tableView)

        Alamofire.request(.GET, "http://swapi.co/api/people/?format=json").responseJSON { (responseData) -> Void in
            let swiftyJsonVar = JSON(responseData.result.value!)
            for element in swiftyJsonVar["results"].arrayValue {
                let name = element["name"].string!
                let homeworld = element["homeworld"].string!
                let object : Dictionary<String, String> = ["name": name, "homeworld": homeworld]
                self.arrResults.append(object)
            }
            if self.arrResults.count > 0 {
                self.tableView.reloadData()
            }
        }

//        Alamofire.request(.GET, "http://api.androidhive.info/contacts/").responseJSON { (responseData) -> Void in
//            let swiftyJsonVar = JSON(responseData.result.value!)
//            
//            if let resData = swiftyJsonVar["contacts"].arrayObject {
//                self.arrResults = resData as! [[String:AnyObject]]
//            }
//            if self.arrResults.count > 0 {
//                self.tableView.reloadData()
//            }
//        }
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "jsonCell")

        var dict = arrResults[indexPath.row]
// Use these lines with: "http://swapi.co/api/people/?format=json"
        cell.textLabel?.text = dict["name"] as? String
        cell.detailTextLabel?.text = dict["homeworld"] as? String
// Use these lines with: "http://api.androidhive.info/contacts/"
//        cell.textLabel?.text = dict["name"] as? String
//        cell.detailTextLabel?.text = dict["email"] as? String
        return cell
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return arrResults.count
    }
}