Question

我有一个5部分的滑块，我想为这部分跳过！我这样做了：

@IBAction func changeCostSlider(_ sender: UISlider) {
    sender.value = roundf(costSlider.value)
}

我还想在滑块的拇指上添加标签，我尝试将此代码添加到上面的代码中：

let trackRect: CGRect  = costSlider.trackRect(forBounds: costSlider.bounds)
    let thumbRect: CGRect  = costSlider.thumbRect(forBounds: costSlider.bounds , trackRect: trackRect, value: costSlider.value)
    let x = thumbRect.origin.x + costSlider.frame.origin.x
    let y = costSlider.frame.origin.y - 20
    sliderLabel.center = CGPoint(x: x, y: y)

但是当我移动我的滑块时，我的标签从我将标签放在故事板中的位置跳转，并且它有一些滞后！有人建议如何将这个标签添加到我的步骤滑块并正常工作吗？！

我认为我的问题是我将我的UILable固定在storyborad中，当我在滑块中移动拇指时，为了mili秒，它会回到固定位置！我怎么解决呢？！

我试图以编程方式添加我的UILabel，直到我触摸拇指才能正常工作！它是如何完成的：

var sliderLableP = UILabel()
@IBAction func changeCostSlider(_ sender: UISlider) {
    sender.value = roundf(costSlider.value)
    print(costSlider.value)
    let trackRect: CGRect  = costSlider.trackRect(forBounds: costSlider.bounds)
    let thumbRect: CGRect  = costSlider.thumbRect(forBounds: costSlider.bounds , trackRect: trackRect, value: costSlider.value)
    let x = thumbRect.origin.x + costSlider.frame.origin.x
    let y = costSlider.frame.origin.y - 20
    sliderLableP.center = CGPoint(x: x, y: y)
}

在我的viewDidLoad中我添加了这个：

sliderLableP = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 20))
    let trackRect: CGRect  = costSlider.trackRect(forBounds: costSlider.bounds)
    let thumbRect: CGRect  = costSlider.thumbRect(forBounds: costSlider.bounds , trackRect: trackRect, value: costSlider.value)
    let x = thumbRect.origin.x + costSlider.frame.origin.x
    let y = costSlider.frame.origin.y - 20
    sliderLableP.center = CGPoint(x: x, y: y)
    sliderLableP.textAlignment = NSTextAlignment.center
    sliderLableP.textColor = UIColor.blue
    self.containerView.addSubview(sliderLableP)
    containerView.bringSubview(toFront: sliderLableP)

Answer 1

此解决方案适用于我：

@IBAction func changeCostSlider(_ sender: UISlider) {
    sender.value = roundf(sender.value)

    let trackRect = sender.trackRect(forBounds: sender.frame)
    let thumbRect = sender.thumbRect(forBounds: sender.bounds, trackRect: trackRect, value: sender.value)
    self.sliderLabel.center = CGPoint(x: thumbRect.midX, y: self.sliderLabel.center.y)
}

Answer 2

我已经创建了 UISlider 的扩展。

extension UISlider {

    func setThumbValueWithLabel() -> CGPoint {
    
        let slidertTrack : CGRect = self.trackRect(forBounds: self.bounds)
        let sliderFrm : CGRect = self.thumbRect(forBounds: self.bounds, trackRect: slidertTrack, value: self.value)
        return CGPoint(x: sliderFrm.origin.x + self.frame.origin.x + 8, y: self.frame.origin.y - 20)
    }
}

这是你如何使用它：-

step1:- 在 UISlider 的 .valueChanged 属性上添加目标操作。

self.slider.addTarget(self, action: #selector(sliderValueChanged),for: .valueChanged)

step2:- 在sliderValueChanged() 方法上，使用扩展方法。

@objc private func sliderValueChanged(_ sender: UISlider) {
    
    self.yourLabel.text = Int(sender.value).description
    self.yourLabel.center = sender.setThumbValueWithLabel() 
}

如何使用步进滑块在滑块拇指上添加UILabel？

2 个答案: