为什么表格视图没有显示任何内容？

Question

我有一个正确设置的表视图，但没有显示任何内容。填充数组并正确设置所有委托。我该如何解决？

 override func viewDidLoad() {
    super.viewDidLoad()
    self.friendstable.rowHeight = 150.0
    friendstable.allowsSelection = false
    self.friendstable.dataSource = self
    self.friendstable.delegate = self
    self.friendstable.registerClass(UITableViewCell.self, forCellReuseIdentifier: "friendcell")
    // Do any additional setup after loading the view.
}

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

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    //var cell = friendstable.dequeueReusableCellWithIdentifier("friendcell", forIndexPath: indexPath)

    let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "friendcell")

    cell.textLabel?.text = titleofsong[indexPath.row]
    cell.detailTextLabel?.text = artist[indexPath.row]
    cell.textLabel?.font = UIFont(name: "Lombok", size: 22)
    cell.textLabel?.textColor =  UIColorFromRGB("4A90E2")
    cell.detailTextLabel?.font = UIFont(name: "Lombok", size: 16)
    cell.detailTextLabel?.textColor =  UIColor.blackColor()

    cell.textLabel?.numberOfLines = 0;
    cell.textLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping

    cell.backgroundColor = UIColor.clearColor()


    return cell
}

Answer 1

func GetRandomObjectID(){
    ObjectIDs = ["objectid1","objectid2","objectid3","objectid4","objectid5","objectid6","objectid7"]
    RandomID = Int(arc4random_uniform(UInt32(ObjectIDs.count)))
}

func CallData(){
    GetRandomObjectID()
    var query : PFQuery = PFQuery(className: "QuestionsandAnswers")
    query.getObjectInBackgroundWithId(ObjectIDs[RandomID]){
        (ObjectHolder : PFObject?, error: NSError?) -> Void in
        if (error == nil) {
            self.Question = ObjectHolder!.valueForKey("Question") as? String
            self.Answers = ObjectHolder!.valueForKey("Answers") as? Array
            self.Answer = ObjectHolder!.valueForKey("Answer") as? String
            if(self.Answers.count > 0){
                self.questionLabel.text = self.Question
                self.Button1.setTitle(self.Answers[0], forState: UIControlState.Normal)
                self.Button2.setTitle(self.Answers[1], forState: UIControlState.Normal)
                self.Button3.setTitle(self.Answers[2], forState: UIControlState.Normal)
                self.Button4.setTitle(self.Answers[3], forState: UIControlState.Normal)
            }
        } else {
            NSLog("There is something wrong!")
        }
    }
}