以编程方式创建的UILabel文本不显示

Question

我是 Swift 的新手。我正在尝试在UIScrollView中创建UILabel。由于某些原因，不显示文本。我确定标签已添加到scrollview中，因为我设置了框架的背景颜色，我可以看到它们显示在scrollview中。单步执行代码时，我可以看到标签的text属性被更新为我传递给我的方法的字符串，但是我看不到文本。我很茫然。有没有人有任何想法？谢谢！

import UIKit

class CustomTableViewCell: UITableViewCell, UIScrollViewDelegate {


    @IBOutlet weak var winLoseValueLabel: UILabel!
    @IBOutlet weak var dateLabel: UILabel!
    @IBOutlet weak var newTotalLabel: UILabel!
    @IBOutlet weak var locationLabel: UILabel!
    @IBOutlet weak var playersScrollView: CustomTableCellScrollView!
    @IBOutlet weak var scrollContentView: UIView!

    var numLinesInScrollView : CGFloat?
    var tblView : UITableView?
    var people : String?


    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
        self.playersScrollView.tblView = tblView
        numLinesInScrollView = 0.0
        self.playersScrollView.contentSize.width = self.scrollContentView.frame.width
        self.playersScrollView.contentSize.height = 100
        self.playersScrollView.addSubview(self.scrollContentView)
    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)

        // Configure the view for the selected state
    }

    func addLabelToScrollView(str : String) {

        // Increment the number of lines in the scrollview
        if numLinesInScrollView != nil {
            numLinesInScrollView!++
        }
        else{
            numLinesInScrollView = 1
        }

        // Get the bounds of the screen
        let screenSize : CGRect = UIScreen.mainScreen().bounds

        // Update the height of the scrollview
        self.playersScrollView.contentSize.height = 20 * numLinesInScrollView!

        // Add a new label to the players scroll view
        let w : CGFloat = self.scrollContentView.frame.width - 350
        let h : CGFloat = 20
        let x : CGFloat = 0
        let y : CGFloat = (numLinesInScrollView! - 1) * h
        let frame : CGRect = CGRect(x: x, y: y, width: w, height: h)
        var person : UILabel = UILabel(frame: frame)
        person.font = UIFont(name: "HelveticaNeue-Bold", size: 12.0)
        person.textColor = UIColor.blackColor()
        person.textAlignment = NSTextAlignment.Center
        switch numLinesInScrollView!{
            case 1:
                person.backgroundColor = UIColor(red: 1.0, green: 0, blue: 0, alpha: 1.0)
            case 2:
                person.backgroundColor = UIColor(red: 0, green: 1.0, blue: 0, alpha: 1.0)
            case 3:
                person.backgroundColor = UIColor(red: 0, green: 0, blue: 1.0, alpha: 1.0)
            case 4:
                person.backgroundColor = UIColor(red: 1.0, green: 0, blue: 1.0, alpha: 1.0)
            default:
                break
        }
        person.text? = str
        self.scrollContentView.addSubview(person)

    }
}

修改：我在str中设置UITableViewController。这是代码。

import UIKit

class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    @IBOutlet weak var tblView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

    }

    override func viewDidLayoutSubviews(){
        super.viewDidLayoutSubviews()

    }

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


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



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

        let cell : CustomTableViewCell = self.tblView.dequeueReusableCellWithIdentifier("ledgerCell", forIndexPath : indexPath) as! CustomTableViewCell

        var values = dataMgr.data[indexPath.row]
        cell.newTotalLabel?.text = "\(values.newTotal)"
        cell.winLoseValueLabel?.text = "\(values.newTotal - values.currentTotal)"
        cell.dateLabel?.text = "5/17/2015"
        cell.addLabelToScrollView("John Doe")
        cell.addLabelToScrollView("Jane Doe")
        cell.addLabelToScrollView("Bob Test")
        cell.addLabelToScrollView("Joe Test")
        cell.tblView = self.tblView

        return cell
    }

}

Answer 1

我从?中移除了person.text? = str并解决了问题。