2016-12-04 55 views
1

这让我疯狂。Swift 3 - DateComponents以Label.Text有时显示“...”

我试图找出两次当前时间和最终将从服务器中抓取的设置时间的差异。

这是时间getTimeDifference()函数暂时没有参数。

let formatter = DateFormatter() 
let userCalender = Calendar.current; 
let requestedComponent : Set<Calendar.Component> = [.month,.day,.hour,.minute,.second] 


public func getTimeDifference() -> DateComponents 
{ 
    formatter.dateFormat = "MM/dd/yyyy hh:mm:ss a" 

    let _startTime = Date() 
    let _endTime = formatter.date(from: "12/05/2016 14:01:00 a") 


    let timeDifference = userCalender.dateComponents(requestedComponent, from: _startTime, to: _endTime!) 
    return timeDifference 
} 

这是我在我的HomepageViewController

@IBOutlet weak var labelHours: UILabel! 
@IBOutlet weak var labelMinutes: UILabel! 
@IBOutlet weak var labelSeconds: UILabel! 

override func viewDidLoad() { 
    super.viewDidLoad() 

    Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(updateCountdown), userInfo: nil, repeats: true).fire() 
    // Do any additional setup after loading the view. 
} 

func updateCountdown() -> Void { 

    let time = Countdown().getTimeDifference() 

    labelHours.text = time.hour?.description 
    labelMinutes.text = time.minute?.description 
    labelSeconds.text = time.second?.description 
} 

当过我运行这段代码就可以正常工作了几秒钟完全没问题但是部分区间它将显示...

Working Not working

问号(?)产生图像ab OVE和去除(?)将所有的标签作为...

labelHours.text = time.hour?.description 
labelMinutes.text = time.minute?.description 
labelSeconds.text = time.second?.description 

labelHours.text = time.hour.description 
labelMinutes.text = time.minute.description 
labelSeconds.text = time.second.description 
+5

每个UILabel是否有足够的宽度来存放两位数字? (例如“24”需要比“11”更多的宽度。) – OOPer

回答

2

使得帧适合文本的大小。你正在寻找的是:

questionsLabel.adjustsFontSizeToFitWidth = true 

上面的代码将改变字体大小,以适应标签的宽度。并且还添加

questionsLabel.textAlignment = .center 

它会在标签中正确呈现文本。