使用Alamofire(Swift 2)从JSON填充tableview单元格

Question

我有以下代码.

import UIKit
import Alamofire

class CheHappyTableViewController: UITableViewController, NSURLConnectionDelegate {

    var happyHours = [HappyHour]()

    override func viewDidLoad() {
        super.viewDidLoad()

        //Load the cell elements
        loadHappyHourElements()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func loadHappyHourElements(){

        let testhappyhour:HappyHour = HappyHour(title: "TEST", image: "TESST", description: "TEST", postedDate: "TEST")
        self.happyHours.append(testhappyhour)

        let url:String = "https://gist.githubusercontent.com/arianitp/036133ebb5af317a595c/raw/f134ec241ec3126bedd6debe5de371e3e01d225b/happyhours.json"
        Alamofire.request(.GET, url, encoding:.JSON).responseJSON
            { response in switch response.result {
            case .Success(let JSON):
                let response = JSON as! NSArray
                for item in response { // loop through data items
                    let obj = item as! NSDictionary
                    let happyhour = HappyHour(title:obj["title"] as! String, image:obj["image"] as! String, description:obj["description"] as! String, postedDate:obj["date"] as! String)
                    self.happyHours.append(happyhour)
                }

            case .Failure(let error):
                print("Request failed with error: \(error)")
                }
        }
        self.tableView.reloadData()
    }

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

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

    //Displays the cells in the table
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        self.tableView.rowHeight = UIScreen.mainScreen().bounds.size.width
        let cellIdentifier = "CheHappyTableViewCellController"
        let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! CheHappyTableViewCellController

        let happyHour = happyHours[indexPath.row]
        cell.lblTitle.text = happyHour.title
        //cell.cheHappyImage = happyHour.photo

        // Configure the cell...
        return cell
    }
}

即使我包含self.tableView.reloadData()在Alamofire请求完成功能中,表格单元格也不会更新.我还定义了一个带有标题的示例对象,并且所有属性都设置为"TEST",这会加载,但是JSON文件不会填充表格.我可以看到文件正在正确下载并读取,但我认为这些元素要么没有被添加到属性变量中,happyHours要么以某种方式重新加载元素.

我从这里尝试了很多解决方案但没有成功.我究竟做错了什么？

Answer 1

你的self.tableView.reloadData()行在回调之外,这意味着在加载数据之前它会被立即调用.试试这个:

func loadHappyHourElements(){

    let testhappyhour:HappyHour = HappyHour(title: "TEST", image: "TESST", description: "TEST", postedDate: "TEST")
    self.happyHours.append(testhappyhour)

    let url:String = "https://gist.githubusercontent.com/arianitp/036133ebb5af317a595c/raw/f134ec241ec3126bedd6debe5de371e3e01d225b/happyhours.json"
    Alamofire.request(.GET, url, encoding:.JSON).responseJSON
        { response in switch response.result {
        case .Success(let JSON):
            let response = JSON as! NSArray
            for item in response { // loop through data items
                let obj = item as! NSDictionary
                let happyhour = HappyHour(title:obj["title"] as! String, image:obj["image"] as! String, description:obj["description"] as! String, postedDate:obj["date"] as! String)
                self.happyHours.append(happyhour)
            }
            self.tableView.reloadData()

        case .Failure(let error):
            print("Request failed with error: \(error)")
            }
    }
}