Xcode 6.3与Swift与tableview的崩溃

Question

在app委托中设置UItabbar之后，我遇到了这个问题。

问题是：

1. 该应用程序只有在按下“发现”选项卡后才会崩溃。
2. 家庭+添加+配置文件ViewControllers是黑色的。

提前谢谢你

var discoveryList = ["topic","topic","topic","topic","topic"]    

override func viewDidLoad() {
    super.viewDidLoad()
    // println(PFUser.currentUser())

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()
}

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

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    // #warning Potentially incomplete method implementation.
    // Return the number of sections.
    return 10
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete method implementation.
    // Return the number of rows in the section.
    return discoveryList.count
}


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


    cell.textLabel?.text = discoveryList[indexPath.row]
    cell.textLabel?.text?.capitalizedString
    cell.textLabel?.textAlignment = NSTextAlignment.Center



    // Configure the cell...

    return cell
}
// App Delegate

 // Create UIWindow within the screen boundaries.
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)

    var nav1 = UINavigationController()
    var first = ccHome(nibName: nil, bundle: nil)
    nav1.viewControllers = [first]
    nav1.tabBarItem = UITabBarItem(title: "Home", image: UIImage(named:"house28.png"), tag: 1)

    var nav2 = UINavigationController()
    var second = ccDiscovery(nibName: nil, bundle: nil)
    nav2.viewControllers = [second]
    nav2.tabBarItem = UITabBarItem(title: "Discovery", image: UIImage(named:"three49.png"), tag: 1)

    var nav3 = UINavigationController()
    var third = ccPosting(nibName: nil, bundle: nil)
    nav3.viewControllers = [third]
    nav3.tabBarItem = UITabBarItem(title: "Add", image: UIImage(named:"add182.png"), tag: 1)

    var nav4 = UINavigationController()
    var four = ccNotification(nibName: nil, bundle: nil)
    nav4.viewControllers = [four]
    nav4.tabBarItem = UITabBarItem(title: "Notification", image: UIImage(named:"connection27.png"), tag: 1)

    var nav5 = UINavigationController()
    var five = ccProfile(nibName: nil, bundle: nil)
    nav5.viewControllers = [five]
    nav5.tabBarItem = UITabBarItem(title: "Profile", image: UIImage(named:"male12.png"), tag: 1)

    var tabs = UITabBarController()
    tabs.viewControllers = [nav1, nav2, nav3,nav4,nav5]

    self.window!.rootViewController = tabs;
    self.window?.makeKeyAndVisible();

Answer 1

我认为问题在于您用于获取UITableViewCell的代码。

你在做..。

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


    cell.textLabel?.text = discoveryList[indexPath.row]
    cell.textLabel?.text?.capitalizedString
    cell.textLabel?.textAlignment = NSTextAlignment.Center



    // Configure the cell...

    return cell
}

这只会重用现有的UITableViewCell，但不会创建一个。如果新的UITableViewCell还不存在，则需要添加一个条件来实例化它。

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
        var cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as? UITableViewCell;
        if (cell == nil)
        {
            cell = SavedAppraisalTableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: cellIdentifier);
        }

        // do some stuff

        return cell!;
}