UILabel不在UIView的中心

Question

我尝试创建可用作进度条或类似内容的自定义UIView（@IBDesignable与IBInspectable s）。我希望在此视图中居中（主要是X轴，但现在也是Y）UILabel。

private func addLabel()
{
    let label = UILabel(frame: CGRectMake(0, 0, self.frame.width / 4, self.frame.height / 4))
    label.center = self.center
    label.textAlignment = .Center
    label.text = "5"
    //Color just to see the whole label
    label.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.5)
    self.addSubview(label)
}

在Interfacebuilder中，标签中心很好：

但是，在我的设备（iPhone 5S）上运行时，标签会略微向右对齐（下图）。我尝试了不同的方法（比如制作标签框架self.frame），但它仍未正确居中。我错过了什么？

override func drawRect(rect: CGRect) {
    // Drawing code
    let center = CGPoint(x:bounds.width/2, y: bounds.height)
    let radius: CGFloat = max(bounds.width, bounds.height)
    let startAngle: CGFloat = π
    let endAngle: CGFloat = 2 * π

    path = UIBezierPath(arcCenter: center, radius: radius / 2 - arcWidth / 2, startAngle: startAngle, endAngle: endAngle, clockwise: true)
    path.lineWidth = arcWidth

    arcBackgroundColor.setStroke()
    path.stroke()

    self.addLayer()
}

private func addLayer()
{
    progressLayer = CAShapeLayer()
    progressLayer.path = self.path.CGPath
    progressLayer.strokeColor = self.progressColor.CGColor
    progressLayer.fillColor = UIColor.clearColor().CGColor
    progressLayer.lineWidth = self.arcWidth

    if animatesOnDraw && progress > 0 {
        self.layer.addSublayer(progressLayer)
        self.animateProgress(0)

    } else {
        progressLayer.strokeEnd = CGFloat(self.progress / self.maxValue)
        progressLayer.opacity = Float(self.progressStrokeEndValue)
        self.layer.addSublayer(progressLayer)
    }


        addLabel() //as shown above

}

Answer 1

问题是const Foxx = require('org/arangodb/foxx'); const TestMessage = Foxx.Model.extends({ schema: {/* ... */} }); ，因为标签的中心和超视图的中心位于不同的坐标系中，因此它们可能不同。改为使用

label.center = self.center

Answer 2

试试这个：

self.label.center = view.center

Answer 3

以编程方式添加UILabel并从

修改UILabel帧

let label = UILabel(frame: CGRectMake(0, 0, self.frame.width / 4, self.frame.height / 4))

要

let label = UILabel(frame: CGRectMake(self.frame.width/2 - (self.frame.height/4)/2, 0, self.frame.width / 4, self.frame.height / 4))

<强> ELSE

实施Autolayout

Answer 4

可能的解决方案是： -

@IBOutlet customView : UIView! 
//Let customView be the outlet of your custom view

func addLabel () {
    let CenterY = customView.center.y
    let CenterX = customView.center.x
    let heightOfCustom = customView.frame.size.height
    let widthOfCustom = customView.frame.size.width
    // If you want a label with height and width 1/4th of the width of the custom view
    let label = UILabel(frame : CGRectMake(CenterX - widthOfCustom/8, CenterY - heightOfCustom/8, widthOfCustom/4, heightOfCustom/4))
    label.text = "5"
    label.textAlignment = .Center
    label.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.5)
    self.addSubview(label)
}