自定义 UISegmentedControl：如何更改所选片段图像的色调？

Question

我已经将这个extension 用于UISegmentedControl，正如你所见here.

但我想UISegementedControl 的工作方式略有不同。当我选择一个段时，我希望所选段的图像将颜色更改为colorGreyLight，而不是将背景颜色更改为colorGreyDark，并将所选段图像更改为UIColor.clearColor()（如您所见here）

那么我该怎么做呢？

我的代码

UISegmented 控件扩展：

extension UISegmentedControl {
    func removeBorders() {
        setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Normal, barMetrics: .Default)
        setBackgroundImage(imageWithColor(tintColor), forState: .Selected, barMetrics: .Default)
        setDividerImage(imageWithColor(UIColor.clearColor()), forLeftSegmentState: .Normal, rightSegmentState: .Normal, barMetrics: .Default)
    }

    // create a 1x1 image with this color
    private func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()
        CGContextSetFillColorWithColor(context, color.CGColor);
        CGContextFillRect(context, rect);
        let image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return image
    }
}

UISegemented 控制：

    let types = ["rectangle", "circle", "triangle"]
    shapeSelector = UISegmentedControl(items: types)
    shapeSelector.frame = CGRectMake(0, 0, sliderHeight*3 + 30, sliderHeight)
    shapeSelector.center = CGPoint(x: drawToolbar.bounds.width/2, y: sliderCenterY)
    shapeSelector.tintColor = colorGreyDark
    shapeSelector.removeBorders()
    shapeSelector.selectedSegmentIndex = 0 //default: select rectangle
    shapeSelector.addTarget(self, action: "selectShape:", forControlEvents: .ValueChanged)
    shapeSelector.setImage(UIImage(named: "rectangle"), forSegmentAtIndex: 0)
    shapeSelector.setImage(UIImage(named: "circle"), forSegmentAtIndex: 1)
    shapeSelector.setImage(UIImage(named: "triangle"), forSegmentAtIndex: 2)
    shapeSelector.contentMode = UIViewContentMode.ScaleAspectFit
    drawToolbar.addSubview(shapeSelector)

如果我使用的是任何问题：

• IOS 9.2
• 斯威夫特 2
• Xcode 7.2

---

更新 好的，所以我按照 Keyur 的建议更改了我的代码（如下面的 cmets 标记）

UISegmented 控件扩展：

extension UISegmentedControl {
    func removeBorders() {
        setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Normal, barMetrics: .Default)
        setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Selected, barMetrics: .Default) //change to clear color
        setDividerImage(imageWithColor(UIColor.clearColor()), forLeftSegmentState: .Normal, rightSegmentState: .Normal, barMetrics: .Default)
    }

    // create a 1x1 image with this color
    private func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()
        CGContextSetFillColorWithColor(context, color.CGColor);
        CGContextFillRect(context, rect);
        let image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return image
    }
}

UISegemented 控制：

    let types = ["rectangle", "circle", "triangle"]
    shapeSelector = UISegmentedControl(items: types)
    shapeSelector.frame = CGRectMake(0, 0, sliderHeight*3 + 30, sliderHeight)
    shapeSelector.center = CGPoint(x: drawToolbar.bounds.width/2, y: sliderCenterY)
    shapeSelector.tintColor = colorGreyDark
    shapeSelector.removeBorders()
    shapeSelector.selectedSegmentIndex = 0 //default: select rectangle
    (shapeSelector.subviews[0] as UIView).tintColor = colorGreyLight //added this line
    shapeSelector.addTarget(self, action: "selectShape:", forControlEvents: .ValueChanged)
    shapeSelector.setImage(UIImage(named: "rectangle"), forSegmentAtIndex: 0)
    shapeSelector.setImage(UIImage(named: "circle"), forSegmentAtIndex: 1)
    shapeSelector.setImage(UIImage(named: "triangle"), forSegmentAtIndex: 2)
    shapeSelector.contentMode = UIViewContentMode.ScaleAspectFit
    drawToolbar.addSubview(shapeSelector)

selectShape()函数：

func selectShape(sender: UISegmentedControl){
    switch sender.selectedSegmentIndex{
    case 0: //rectangle
        shapeType = "rectangle"
        (sender.subviews[0] as UIView).tintColor = colorGreyLight
        (sender.subviews[1] as UIView).tintColor = colorGreyDark
        (sender.subviews[2] as UIView).tintColor = colorGreyDark
    case 1: //circle
        shapeType = "circle"
        (sender.subviews[0] as UIView).tintColor = colorGreyDark
        (sender.subviews[1] as UIView).tintColor = colorGreyLight
        (sender.subviews[2] as UIView).tintColor = colorGreyDark
    case 2: //triangle
        shapeType = "triangle"
        (sender.subviews[0] as UIView).tintColor = colorGreyDark
        (sender.subviews[1] as UIView).tintColor = colorGreyDark
        (sender.subviews[2] as UIView).tintColor = colorGreyLight
    default:
        shapeType = "rectangle"
        (sender.subviews[0] as UIView).tintColor = colorGreyLight
        (sender.subviews[1] as UIView).tintColor = colorGreyDark
        (sender.subviews[2] as UIView).tintColor = colorGreyDark
    }
}

除非我尝试过，否则所选形状并不总是突出显示的形状，如您所见here。它似乎几乎是随机突出显示形状，我不明白为什么。

对此的任何帮助将不胜感激！

Answer 1

(shapeSelector.subviews[2] as UIView).tintColor = UIColor .redColor()
(shapeSelector.subviews[1] as UIView).tintColor = UIColor .redColor()
(shapeSelector.subviews[0] as UIView).tintColor = UIColor .redColor()

Answer 2

1. 在您的 removeborders() 函数中设置颜色。

setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Normal, barMetrics: .Default) setBackgroundImage(imageWithColor(UIColor.lightGrayColor()), forState: .Selected, barMetrics: .Default)

Answer 3

感谢this post.，我找到了答案

显然选择的索引不是分配色调颜色的可靠方法。相反，我必须自己跟踪这些细分市场。

这就是我在创建UISegmentedControl shapeSelector 后所做的：

var segments: [UIView] = [UIView]()
for i in 0...shapeSelector.subviews.count-1{
    segments.append(shapeSelector.subviews[i])
}

在我的UISegmentedControl 的函数中我做了：

func selectShape(sender: UISegmentedControl){
    let i = sender.selectedSegmentIndex
    for s in segments{
        s.tintColor = colorGreyDark
    }
    segments[i].tintColor = colorGreyLight

    switch i{
    case 0:
        shapeType = "rectangle"
    case 1:
        shapeType = "circle"
    case 2:
        shapeType = "triangle"
    default:
        shapeType = "rectangle"
    }
}

现在一切正常！

---

完整代码

extension UISegmentedControl {
    func removeBorders() {
        setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Normal, barMetrics: .Default)
        setBackgroundImage(imageWithColor(UIColor.clearColor()), forState: .Selected, barMetrics: .Default)
        setDividerImage(imageWithColor(UIColor.clearColor()), forLeftSegmentState: .Normal, rightSegmentState: .Normal, barMetrics: .Default)
}

    // create a 1x1 image with this color
    private func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()
        CGContextSetFillColorWithColor(context, color.CGColor);
        CGContextFillRect(context, rect);
        let image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return image
    }
}

class DrawViewController: UIViewController {

    var shapeSelector: UISegmentedControl = UISegmentedControl()
    var segments: [UIView] = [UIView]()

    override func viewDidLoad() {
        super.viewDidLoad()

        //set up shape selector
        let types = ["rectangle", "circle", "triangle"]
        shapeSelector = UISegmentedControl(items: types)
        shapeSelector.frame = CGRectMake(shapeTypeLabel.frame.maxX + sliderSpace, 0, sliderHeight*3 + 30, sliderHeight)
        shapeSelector.center.y = shapeTypeLabel.center.y
        shapeSelector.tintColor = colorGreyDark
        shapeSelector.removeBorders()
        shapeSelector.addTarget(self, action: "selectShape:", forControlEvents: .ValueChanged)
        shapeSelector.setImage(UIImage(named: "rectangle"), forSegmentAtIndex: 0)
        shapeSelector.setImage(UIImage(named: "circle"), forSegmentAtIndex: 1)
        shapeSelector.setImage(UIImage(named: "triangle"), forSegmentAtIndex: 2)
        for i in 0...shapeSelector.subviews.count-1{
            segments.append(shapeSelector.subviews[i])
        }
        shapeSelector.selectedSegmentIndex = 0 //default: select rectangle
        segments[0].tintColor = colorGreyLight
        shapeSelector.contentMode = UIViewContentMode.ScaleAspectFit
        drawToolbar.addSubview(shapeSelector)
    }

    func selectShape(sender: UISegmentedControl){
        let i = sender.selectedSegmentIndex
        for s in segments{
            s.tintColor = colorGreyDark
        }
        segments[i].tintColor = colorGreyLight

        switch i{
        case 0:
            shapeType = "rectangle"
        case 1:
            shapeType = "circle"
        case 2:
            shapeType = "triangle"
        default:
            shapeType = "rectangle"
        }
    }
}