快速下載 json 並在 UITableView 中顯示

Question

我進行了一次初級 iOS 工作面試的測試。 它是從 twitch.tv 獲取最新游戲並在 UITableView 上使用自定義單元格顯示它們。 代碼和注釋一起在下面。 除了使用庫獲取json之外，有人可以指出錯誤嗎？ 我認為數據模型可以更好，而不是使用三個不同的表。

import UIKit

class ViewController: UIViewController, UITableViewDelegate {

@IBOutlet weak var tableView: UITableView!

//This is a the quick fix, another way would be to create a data class with objects and properties: name, viewers and image. 
//Then create an arrray of objects where there are stored. Although the implemented solution is a quick faster and has a little les memory usage.
//setting up different arrays for each data type to access them globally at some point
var JSONGameName: [String] = []
var JSONViewers: [Int] = []
var JSONGameImages: [String] = []


override func viewDidLoad() {
    super.viewDidLoad()
    loadAndDecodeJson()

}


//this functions uses the default way to implement json in swift. For more advanced data or multiple json files
//the suggestions is to use an external library like SwiftyJson
func loadAndDecodeJson(){

    //defining the url of the nsurl string to download
    //if not secure URL allow it in the plist file
    let url = NSURL(string: "https://api.twitch.tv/kraken/games/top")

    //create the task to handle the url
    let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {(data, response, error) -> Void in

        //when task completes this will run
        //need to check if data is not nil
        if error == nil {

            //serialize the json to a dictionary
            do {
                let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary

                //loop through the data but first check if it hsa something in it
                if jsonResult.count > 0 {

                    if let items = jsonResult["top"] as? NSArray {

                        for item in items {

                            if let viewers = item["viewers"] as? NSInteger {
                                print(viewers)
                                self.JSONViewers.append(viewers)
                            }

                            if let games = item["game"] as? NSDictionary {
                                if let name = games["name"] as? NSString {
                                    print (name)
                                    self.JSONGameName.append(name as String)

                                }
                                if let logo = games["logo"] as? NSDictionary {
                                    if let small = logo["small"] as? NSString {
                                        print (small)
                                        self.JSONGameImages.append(small as String)
                                    }
                                }
                            }

                        }
                    }
                }

                //reload table after json parsing is done
                dispatch_async(dispatch_get_main_queue(), { () -> Void in
                    self.tableView.reloadData()
                })
            } catch {

                print("error: parsing json")

            }

        } else {

            //Show error message that there is probably no connection
            let alert = UIAlertController(title: "Oopps..", message: "The was an error downloading data", preferredStyle: UIAlertControllerStyle.Alert)
            alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
            self.presentViewController(alert, animated: true, completion: nil)
        }
    }

    //execute the async task
    task.resume()
}

//defining number os section
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}
//function to determine the number of list items
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return JSONGameName.count
}

//the view of every cell of the list
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    //custom cell identifier
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! ViewControllerCell

    //setting up the images and casting them from strings to UIImages
    let imageURL = NSURL(string: JSONGameImages[indexPath.row])
    let data = NSData(contentsOfURL: imageURL!)

    //setting game name, images and viewers on cells
    cell.gameName?.text = JSONGameName[indexPath.row]
    cell.gameViewers?.text = String (JSONViewers[indexPath.row])
    cell.gameImage?.image = UIImage(data: data!)


    return cell
}
}

這是自定義單元格

import UIKit

class ViewControllerCell: UITableViewCell {

@IBOutlet weak var gameImage: UIImageView!
@IBOutlet weak var gameName: UILabel!
@IBOutlet weak var gameViewers: UILabel!

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}

}

PS：我無緣無故得到了一些反對票。 這個問題有什么問題？ 我有一個解決方案並集思廣益以尋求更好的解決方案。

Answer 1

import UIKit

class ViewController: UIViewController, UITableViewDelegate {

    @IBOutlet weak var tableView: UITableView!

    //This is a the quick fix, another way would be to create a data class with objects and properties: name, viewers and image.
    //Then create an arrray of objects where there are stored. Although the implemented solution is a quick faster and has a little les memory usage.
    //setting up different arrays for each data type to access them globally at some point
    var JSONGameName: [String] = []
    var JSONViewers: [Int] = []
    var JSONGameImages: [String] = []


    override func viewDidLoad() {
        super.viewDidLoad()
        loadAndDecodeJson()

    }


    //this functions uses the default way to implement json in swift. For more advanced data or multiple json files
    //the suggestions is to use an external library like SwiftyJson
    func loadAndDecodeJson(){

        //defining the url of the nsurl string to download
        //if not secure URL allow it in the plist file
        let url = NSURL(string: "https://api.twitch.tv/kraken/games/top")

        //create the task to handle the url
        let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {(data, response, error) -> Void in

            //when task completes this will run
            //need to check if data is not nil
            if error == nil {

                //serialize the json to a dictionary

                var errorJson:NSError?=nil
                var jsonResult=NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &errorJson) as? NSDictionary
                //loop through the data but first check if it hsa something in it
                if jsonResult!.count > 0 {

                    if let items = jsonResult!["top"] as? NSArray {

                        for item in items {

                            if let viewers = item["viewers"] as? NSInteger {
                                print(viewers)
                                self.JSONViewers.append(viewers)
                            }

                            if let games = item["game"] as? NSDictionary {
                                if let name = games["name"] as? NSString {
                                    print (name)
                                    self.JSONGameName.append(name as String)

                                }
                                if let logo = games["logo"] as? NSDictionary {
                                    if let small = logo["small"] as? NSString {
                                        print (small)
                                        self.JSONGameImages.append(small as String)
                                    }
                                }
                            }

                        }
                    }
                }

                //reload table after json parsing is done
                dispatch_async(dispatch_get_main_queue(), { () -> Void in
                    self.tableView.reloadData()
                })


            } else {

                //Show error message that there is probably no connection
                let alert = UIAlertController(title: "Oopps..", message: "The was an error downloading data", preferredStyle: UIAlertControllerStyle.Alert)
                alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
                self.presentViewController(alert, animated: true, completion: nil)
            }
        }

        //execute the async task
        task.resume()
    }

    //defining number os section
    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return 1
    }
    //function to determine the number of list items
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return JSONGameName.count
    }

    //the view of every cell of the list
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

        //custom cell identifier
        var cell:CustomTableViewCell? = tableView.dequeueReusableCellWithIdentifier("Cell") as? CustomTableViewCell
        cell=nil
        if cell==nil{

            cell=NSBundle.mainBundle().loadNibNamed("CustomTableViewCell", owner: self, options: nil)[0] as? CustomTableViewCell
        }


        //setting up the images and casting them from strings to UIImages
        let imageURL = NSURL(string: JSONGameImages[indexPath.row])
        let data = NSData(contentsOfURL: imageURL!)

        //setting game name, images and viewers on cells
        cell!.gameName?.text = JSONGameName[indexPath.row]
        cell!.gameViewers?.text = String (JSONViewers[indexPath.row])
        cell!.gameImage?.image = UIImage(data: data!)


        return cell!
    }
}

從下面的鏈接下載源代碼，它在我身邊工作。
讓我知道是否有任何錯誤？ https://www.dropbox.com/sh/9ochfbi1pyxnt8l/AABlUC0PojpTmiEvYIYEJrAMA?dl=0