在UIPageControl中添加点的边框

Question

我想在UIPageControl中为点添加边框颜色。这是它的小图：

我可以通过从XCode配置它来放置第二个点，但我不能让第一个和第三个圆圈在里面空。有没有一种简单的方法来实现这一目标？

谢谢 ：）

Answer 1

使用UIPageControl的当前属性是不可能的。但你可以通过集成任何模仿iOS third party功能的UIPageControl页面控件来实现。

其他答案已应用补丁。我非常不同意这个解决方案。

Answer 2

编辑 - Swift 3＆4扩展以实现相同的结果 -

extension UIPageControl {

    func customPageControl(dotFillColor:UIColor, dotBorderColor:UIColor, dotBorderWidth:CGFloat) {
        for (pageIndex, dotView) in self.subviews.enumerated() {
            if self.currentPage == pageIndex {
                dotView.backgroundColor = dotFillColor
                dotView.layer.cornerRadius = dotView.frame.size.height / 2
            }else{
                dotView.backgroundColor = .clear
                dotView.layer.cornerRadius = dotView.frame.size.height / 2
                dotView.layer.borderColor = dotBorderColor.cgColor
                dotView.layer.borderWidth = dotBorderWidth
            }
        }
    }

}

使用它在viewDidLoad（）或viewDidAppear（）中写下面的代码

pageControl.customPageControl(dotFillColor: .orange, dotBorderColor: .green, dotBorderWidth: 2)

在Objective-C中使用以下代码 -

- (void) customPageControlWithFillColor:(UIColor*)dotFillColor borderColor:(UIColor*)dotBorderColor borderWidth:(CGFloat)dotBorderWidth {
    for (int pageIndex = 0; pageIndex < _pageControl.numberOfPages; pageIndex++) {
        UIView* dotView = [_pageControl.subviews objectAtIndex:pageIndex];
        if (_pageControl.currentPage == pageIndex) {
            dotView.backgroundColor = dotFillColor;
            dotView.layer.cornerRadius = dotView.frame.size.height / 2;
        } else {
            dotView.backgroundColor = [UIColor clearColor];
            dotView.layer.cornerRadius = dotView.frame.size.height / 2;
            dotView.layer.borderColor = dotBorderColor.CGColor;
            dotView.layer.borderWidth = dotBorderWidth;
        }
    }
}

输出 -

Answer 3

另一种方法是使用正确尺寸的图案图像（目前直径为7个点）。结果如下：

以下是它的完成方式：

let image = UIImage.outlinedEllipse(size: CGSize(width: 7.0, height: 7.0), color: .darkGray)
self.pageControl.pageIndicatorTintColor = UIColor.init(patternImage: image!)
self.pageControl.currentPageIndicatorTintColor = .darkGray

使用这个简单的小扩展到UIImage：

/// An extension to `UIImage` for creating images with shapes.
extension UIImage {

    /// Creates a circular outline image.
    class func outlinedEllipse(size: CGSize, color: UIColor, lineWidth: CGFloat = 1.0) -> UIImage? {

        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
        guard let context = UIGraphicsGetCurrentContext() else {
                return nil
        }

        context.setStrokeColor(color.cgColor)
        context.setLineWidth(lineWidth)
        // Inset the rect to account for the fact that strokes are
        // centred on the bounds of the shape.
        let rect = CGRect(origin: .zero, size: size).insetBy(dx: lineWidth * 0.5, dy: lineWidth * 0.5)
        context.addEllipse(in: rect)
        context.strokePath()

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

这样做的缺点是，如果操作系统更新中的点大小发生变化，则图像看起来会很奇怪，因为它会被平铺或剪裁。

Answer 4

来自@RiosK的SWIFT 3版本

func updatePageControl() {
    for (index, dot) in pageControl.subviews.enumerated() {
        if index == pageControl.currentPage {
            dot.backgroundColor = dotColor
            dot.layer.cornerRadius = dot.frame.size.height / 2;
        } else {
            dot.backgroundColor = UIColor.clear
            dot.layer.cornerRadius = dot.frame.size.height / 2
            dot.layer.borderColor = dotColor.cgColor
            dot.layer.borderWidth = dotBorderWidth
        }
    }
}

Answer 5

我正在使用SMPageControl。这是一个用Objective-C编写的非常棒的框架，所以它能够使用Swift 2和Swift 3。

用法很简单：

pod 'SMPageControl'

然后在你的PageViewController：

import SMPageControl

class MyController: UIPageViewController {

     var pageControl = SMPageControl()

     override func viewDidLoad() {
        super.viewDidLoad()

        stylePageControl()
    }

private func stylePageControl() {

    pageControl = SMPageControl(frame: CGRect(x: 0, y: self.view.frame.size.height - 50, width: self.view.frame.size.width, height: 50))
    pageControl.numberOfPages = yourPageControllerArray.count

//  the first (first) picture is the item in the bar, that is unused
//  the second (currentFirst) is an item that we use, when this is the current active page
//  in this example, we don't have dots, but we use "pictues" as dots

    let first = UIImage(named: "pageHome")?.imageWithColor(UIColor.grayColor())
    let currentFirst = first?.imageWithColor(UIColor.whiteColor())

    pageControl.setImage(first, forPage: 0)
    pageControl.setCurrentImage(currentFirst, forPage: 0)

    let second = UIImage(named: "pageMusic")?.imageWithColor(UIColor.grayColor())
    let currentSecond = second?.imageWithColor(UIColor.whiteColor())

    pageControl.setImage(second, forPage: 1)
    pageControl.setCurrentImage(currentSecond, forPage: 1)

    pageControl.indicatorMargin = 30.0 // this is the space between the dots

    self.view.addSubview(pageControl)
}

UIImage扩展我用过：

extension UIImage {

    func imageWithColor(color1: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        color1.setFill()

        let context = UIGraphicsGetCurrentContext()! as CGContextRef
        CGContextTranslateCTM(context, 0, self.size.height)
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, CGBlendMode.Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect
        CGContextClipToMask(context, rect, self.CGImage!)
        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext()! as UIImage
        UIGraphicsEndImageContext()

        return newImage
    }

}

结果如下：

现在我们当然可以使用彩色圆点作为图像，（空白颜色为未使用颜色和填充颜色）然后我们会得到询问结果。

Answer 6

只需添加这两行并添加所需的图像!!

pageControl.currentPageIndicatorTintColor  = UIColor.init(patternImage: UIImage(named: "slider_selected")!)

pageControl.pageIndicatorTintColor =  UIColor.init(patternImage: UIImage(named: "slider")!)

Answer 7

Swift 4.您可以指定borderColor，然后观察currentPage属性以更改点的边框：

class CustomPageControl: UIPageControl {

    var borderColor: UIColor = .clear

    override var currentPage: Int {
        didSet {
            updateBorderColor()
        }
    }

    func updateBorderColor() {
        subviews.enumerated().forEach { index, subview in
            if index != currentPage {
                subview.layer.borderColor = borderColor.cgColor
                subview.layer.borderWidth = 1
            } else {
                subview.layer.borderWidth = 0
            }
        }
    }

}

Answer 8

需要在viewDidAppear中添加它

 for (int i = 0; i < _pageControl.numberOfPages; i++) {
        UIView* dot = [_pageControl.subviews objectAtIndex:i];
        if (i == _pageControl.currentPage) {
            dot.backgroundColor = [UIColor whiteColor];
            dot.layer.cornerRadius = dot.frame.size.height / 2;
        } else {
            dot.backgroundColor = [UIColor clearColor];
            dot.layer.cornerRadius = dot.frame.size.height / 2;
            dot.layer.borderColor = [UIColor whiteColor].CGColor;
            dot.layer.borderWidth = 1;
        }
    }