Question

我已经浏览过有关此主题的各种教程和帖子，但我似乎无法为我的项目制定解决方案。从本质上讲，我正在努力实现一个＆＃34;拉动刷新＆＃34;在iOS上的TableView中，然后通过Web服务器重新加载一些数据，然后使用最新的数据集重新加载我的表。

从测试开始，似乎我的＆＃34;拉动刷新＆＃34;正在工作，其中我成功地从我的Web服务请求中提取最新数据。然而，似乎失败的是表格的单元格实际上并没有使用最新数据进行更新。这是我在 TableViewController ;

中的内容

import UIKit

class MinionsTableViewController: UITableViewController {
let minions: [Minion]
required init(coder aDecoder: NSCoder!) {
    minions = Minion.fetchMinionData()
    super.init(coder: aDecoder)
}

override func viewDidLoad() {

    super.viewDidLoad()
    let defaults = NSUserDefaults(suiteName: "group.com.example.myapp.data")
    NSKeyedArchiver.setClassName("Minion", forClass: Minion.self)
    defaults?.setObject(NSKeyedArchiver.archivedDataWithRootObject(minions), forKey: "minions")

    self.refreshControl?.addTarget(self, action: "handleRefresh:", forControlEvents: UIControlEvents.ValueChanged)
}

func handleRefresh(refreshControl: UIRefreshControl) {
    let minions: [Minion]
    minions = Minion.fetchMinionData()
    for minion in minions {
        println(minion.now!)
    }
    self.tableView.reloadData()
    refreshControl.endRefreshing()
}

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

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("minionCell", forIndexPath: indexPath) as! UITableViewCell

    let minion = minions[indexPath.row]

    if let name = minion.name {
        cell.imageView?.image = UIImage(named: minion.name!)
        cell.textLabel?.text = minion.name ?? "Minion"
        cell.detailTextLabel?.text = "Data: \(minion.now!)"
    } else {
        cell.imageView?.image = UIImage(named: "Dave")
        cell.textLabel?.text = "No data available."
        cell.detailTextLabel?.text = "Sorry, nothing to present here!"
    }

    return cell
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "ShowDetail" {
        let indexPath = self.tableView.indexPathForSelectedRow()
        //println(indexPath)
        let minionDetail = minions[indexPath!.row]
        let controller = (segue.destinationViewController as! UINavigationController).topViewController as! DetailedViewController
        controller.detailItem = minionDetail
    }
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    if let selectedIndexPath = self.tableView.indexPathForSelectedRow() {
        self.tableView.deselectRowAtIndexPath(selectedIndexPath, animated: true)

    }
}
}

我的＆＃34; minion.now！＆＃34;变量是一些带有当前时间戳的JSON数据，从我的println输出中，我可以看到它实际上在我拉动刷新时更新。但是，我的表格单元格似乎根本没有更新。

任何想法都会非常感激。谢谢！

Answer 1

在下面的方法中，您将创建一个局部变量，该变量与您的类属性没有任何关系。

func handleRefresh(refreshControl: UIRefreshControl) {
    let minions: [Minion]//Delete this line
    minions = Minion.fetchMinionData() //self.minions = Minion.fetchMinionData()
    for minion in minions {
        println(minion.now!)
    }
    self.tableView.reloadData()
    refreshControl.endRefreshing()
}

所以将行转换为

self.minions = Minion.fetchMinionData()

并且您在类级别声明的属性使其像

var minions: [Minion]

完整代码..

import UIKit

class MinionsTableViewController: UITableViewController {
var minions: [Minion]
required init(coder aDecoder: NSCoder!) {
    minions = Minion.fetchMinionData()
    super.init(coder: aDecoder)
}

override func viewDidLoad() {

    super.viewDidLoad()
    let defaults = NSUserDefaults(suiteName: "group.com.example.myapp.data")
    NSKeyedArchiver.setClassName("Minion", forClass: Minion.self)
    defaults?.setObject(NSKeyedArchiver.archivedDataWithRootObject(minions), forKey: "minions")

    self.refreshControl?.addTarget(self, action: "handleRefresh:", forControlEvents: UIControlEvents.ValueChanged)
}

func handleRefresh(refreshControl: UIRefreshControl) {
    self.minions = Minion.fetchMinionData()
    for minion in minions {
        println(minion.now!)
    }
    self.tableView.reloadData()
    refreshControl.endRefreshing()
}

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

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("minionCell", forIndexPath: indexPath) as! UITableViewCell

    let minion = minions[indexPath.row]

    if let name = minion.name {
        cell.imageView?.image = UIImage(named: minion.name!)
        cell.textLabel?.text = minion.name ?? "Minion"
        cell.detailTextLabel?.text = "Data: \(minion.now!)"
    } else {
        cell.imageView?.image = UIImage(named: "Dave")
        cell.textLabel?.text = "No data available."
        cell.detailTextLabel?.text = "Sorry, nothing to present here!"
    }

    return cell
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "ShowDetail" {
        let indexPath = self.tableView.indexPathForSelectedRow()
        //println(indexPath)
        let minionDetail = minions[indexPath!.row]
        let controller = (segue.destinationViewController as! UINavigationController).topViewController as! DetailedViewController
        controller.detailItem = minionDetail
    }
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    if let selectedIndexPath = self.tableView.indexPathForSelectedRow() {
        self.tableView.deselectRowAtIndexPath(selectedIndexPath, animated: true)

    }
}
}

难以在Swift中重新加载TableView

1 个答案: