ios - 在 Swift 的分段控件中选择任何分段时如何创建和突出显示红色细线(向下)

Question

我有一个分段控件，如图所示有 4 个分段。

敌人，例如:有线线路、可管理的移动性

我想在选择任何段时在底部(发际线)获得红色；基本上它应该在选定的段显示红线

我现在的代码如下

func changeColor(sender: UISegmentedControl){

    if sender.selectedSegmentIndex == 0 {
        UIView.animateWithDuration(0.5, animations: {
            self.containerAccountSummary.alpha = 1
            self.containerLocationTracker.alpha = 0
            self.containerWireline.alpha = 0
            self.containerManagedMobility.alpha = 0
            self.containerMobileVoiceAndData.alpha = 0
        })
    } else if sender.selectedSegmentIndex == 1{
        UIView.animateWithDuration(0.5, animations: {
            self.containerAccountSummary.alpha = 0
            self.containerLocationTracker.alpha = 1
            self.containerWireline.alpha = 0
            self.containerManagedMobility.alpha = 0
            self.containerMobileVoiceAndData.alpha = 0
        })
    }else if sender.selectedSegmentIndex == 2{
        UIView.animateWithDuration(0.5, animations: {
            self.containerAccountSummary.alpha = 0
            self.containerLocationTracker.alpha = 0
            self.containerWireline.alpha = 1
            self.containerManagedMobility.alpha = 0
            self.containerMobileVoiceAndData.alpha = 0
        })

    }else if sender.selectedSegmentIndex == 3{
        UIView.animateWithDuration(0.5, animations: {
            self.containerAccountSummary.alpha = 0
            self.containerLocationTracker.alpha = 0
            self.containerWireline.alpha = 0
            self.containerManagedMobility.alpha = 1
            self.containerMobileVoiceAndData.alpha = 0
        })

    }else {
        UIView.animateWithDuration(0.5, animations: {
            self.containerAccountSummary.alpha = 0
            self.containerLocationTracker.alpha = 0
            self.containerWireline.alpha = 0
            self.containerManagedMobility.alpha = 0
            self.containerMobileVoiceAndData.alpha = 1
        })
    }
}

有什么建议吗？

Answer 1

您可以将 UIView 用作细线并将其放置在 Storyboard上的分段控件下方。指定它的颜色和高度。将其宽度设置为等于分段控件中的单个分段，然后在调用分段控件操作时，采用选定的分段索引并根据该索引，通过提供 X 位置、Y 位置、高度和宽度来更改 UIView 的框架。然后将此框架设置为您的细线并在细线上调用方法 layoutIfNeeded()。它会改变发际线的框架。在下面编写一个函数并在您的段控件的操作方法中调用此函数:

override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        let segmentControlFrame = self.view.convert(segmentControl.frame, from: segmentControl.superview)
        let widthForHairLine = segmentControlFrame.width / 4
        if segmentControl.selectedSegmentIndex == 0 {
            firstFrame = CGRect(x: segmentControlFrame.minX, y: segmentControlFrame.maxY , width: widthForHairLine, height: 5)
        } else if segmentControl.selectedSegmentIndex == 1 {
            firstFrame = CGRect(x: (segmentControlFrame.minX + widthForLine), y: segmentControlFrame.maxY , width: widthForHairLine, height: 5)
        } else if segmentControl.selectedSegmentIndex == 2 {
            firstFrame = CGRect(x: (segmentControlFrame.minX + widthForLine + widthForLine), y: segmentControlFrame.maxY , width: widthForHairLine, height: 5)
        } else if segmentControl.selectedSegmentIndex == 3 {
            firstFrame = CGRect(x: (segmentControlFrame.minX + widthForLine + widthForLine + widthForLine), y: segmentControlFrame.maxY , width: widthForHairLine, height: 5)
        self.hairline.backgroundColor = UIColor.red
        self.hairline.frame = firstFrame!
        self.hairline.layoutIfNeeded()
    }