如何创造＆amp;当在Swift的分段控件中选择任何分段时，突出显示红色发线（向下）

Question

我有一个分段控件，它有4个段，如图所示。

敌人：有线，管理移动

当我选择任何片段时，我想在底部（发际线）获得红色;基本上它应该在选定的段显示红线

我目前的代码如下

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
        })
    }
}

任何建议？

Answer 1

您可以将UIView用于发际线并将其放置在故事板上的分段控件下方。指定它的颜色和高度。在段控件中将其宽度等于sigle段，然后在调用段控制操作时，采用选定的段索引并根据该索引，通过提供X位置，Y位置，高度来更改UIView的帧和宽度。然后将此框架设置为发际线并在发际线上调用方法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()
    }