iOS:tableView.reloadData() 在 swift3 中不起作用

Question

我是 Swift 的新手，我试图在 Swift 中更新数据后重新加载我的 TableView ，但它似乎不起作用。当我更改选项卡并返回时，tableView 会重新加载但不会自动加载。这是我的代码:

我的 TableView Controller :

 class AllChannelTableViewController: UITableViewController {

    var modelChannel = [AllCnannelModel]()

    let realm = try! Realm()

    lazy var channels: Results<ChannelData> = { self.realm.objects(ChannelData.self) }()

    override func viewDidLoad() {
        super.viewDidLoad()
        defaultChannel()
    }

    func defaultChannel() {

        if channels.count == 0 {

           SVProgressHUD.show(withStatus: "dowload")

            let URL = "http://52.50.138.211:8080/ChanelAPI/chanels"

            Alamofire.request(URL).responseArray { (response: DataResponse<[AllCnannelModel]>) in

                let channelArray = response.result.value

                if let channelArray = channelArray {
                    for channel in channelArray {
                        try! self.realm.write() {
                            let newChannel = ChannelData()
                            newChannel.category_id = channel.category_id!
                            newChannel.idChannel = channel.id!
                            print(newChannel.idChannel)
                            newChannel.name = channel.name!
                            print(newChannel.name)
                            newChannel.picture = channel.picture
                            newChannel.url = channel.url!
                            print(newChannel.url)
                            self.realm.add(newChannel, update: true)
                        }
                    }
                }
            }
            DispatchQueue.main.async{
                self.tableView.reloadData()
                self.channels = self.realm.objects(ChannelData.self)
            }
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
       // self.tableView.reloadData()
        return self.channels.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! AllChannelTableViewCell

        let strUrl = channels[indexPath.row].picture

        cell.nameChannel.text = self.channels[indexPath.row].name
        cell.urlChannel.text = self.channels[indexPath.row].url
        cell.imageChannel.downloadFrom(url: URL(string: strUrl)!)

        SVProgressHUD.dismiss()

        return cell
    }
}

Answer 1

您需要在设置完datasource 数组后重新加载tableView。此外，您目前正在 Alamofire block 外重新加载 tableView 但它应该在 Alamofire 请求 block 内。所以像这样更改您的重新加载代码。

func defaultChannel() {

    if channels.count == 0 {

       SVProgressHUD.show(withStatus: "dowload")

        let URL = "http://52.50.138.211:8080/ChanelAPI/chanels"

        Alamofire.request(URL).responseArray { (response: DataResponse<[AllCnannelModel]>) in

            let channelArray = response.result.value

            if let channelArray = channelArray {
                for channel in channelArray {
                    try! self.realm.write() {
                        let newChannel = ChannelData()
                        newChannel.category_id = channel.category_id!
                        newChannel.idChannel = channel.id!
                        print(newChannel.idChannel)
                        newChannel.name = channel.name!
                        print(newChannel.name)
                        newChannel.picture = channel.picture
                        newChannel.url = channel.url!
                        print(newChannel.url)
                        self.realm.add(newChannel, update: true)
                    }
                }
            }
            DispatchQueue.main.async{
                //First set array
                self.channels = self.realm.objects(ChannelData.self)
                //Now reload the tableView
                self.tableView.reloadData()
            }
        }

    }
}