如何在swift中创建虚线？

Question

我想知道如何快速制作一条虚线： - - - - - - - - 而不是像这样的常规直线：----------------，我知道我可以制作多行，但如果我可以在一行写它，那将需要这么多不必要的代码。顺便说一句，它必须在CoreGraphics中。

Answer 1

您可以使用与Objective-C相同的方式创建虚线，除了您将使用Swift。

以下是使用UIBezierPath执行此操作的方法：

let  path = UIBezierPath()

let  p0 = CGPoint(x: self.bounds.minX, y: self.bounds.midY)
path.move(to: p0)

let  p1 = CGPoint(x: self.bounds.maxX, y: self.bounds.midY)
path.addLine(to: p1)

let  dashes: [ CGFloat ] = [ 16.0, 32.0 ]
path.setLineDash(dashes, count: dashes.count, phase: 0.0)

path.lineWidth = 8.0
path.lineCapStyle = .butt
UIColor.magenta.set()
path.stroke()

以下是使用UIBezierPath绘制虚线的方法：

let  path = UIBezierPath()

let  p0 = CGPointMake(CGRectGetMinX(self.bounds), CGRectGetMidY(self.bounds))
path.moveToPoint(p0)

let  p1 = CGPointMake(CGRectGetMaxX(self.bounds), CGRectGetMidY(self.bounds))
path.addLineToPoint(p1)

let  dashes: [ CGFloat ] = [ 0.0, 16.0 ]
path.setLineDash(dashes, count: dashes.count, phase: 0.0)
path.lineWidth = 8.0
path.lineCapStyle = .Round
UIColor.magentaColor().set()
path.stroke()

以下是如何使用CGContext绘制虚线：

let  context: CGContext = UIGraphicsGetCurrentContext()!

let  p0 = CGPointMake(CGRectGetMinX(self.bounds), CGRectGetMidY(self.bounds))
CGContextMoveToPoint(context, p0.x, p0.y)

let  p1 = CGPointMake(CGRectGetMaxX(self.bounds), CGRectGetMidY(self.bounds))
CGContextAddLineToPoint(context, p1.x, p1.y)

let  dashes: [ CGFloat ] = [ 16.0, 32.0 ]
CGContextSetLineDash(context, 0.0, dashes, dashes.count)

CGContextSetLineWidth(context, 8.0)
CGContextSetLineCap(context, .Butt)
UIColor.blueColor().set()
CGContextStrokePath(context)

Answer 2

斯威夫特4

@IBOutlet var dashedView: UIView!

func drawDottedLine(start p0: CGPoint, end p1: CGPoint, view: UIView) {
    let shapeLayer = CAShapeLayer()
    shapeLayer.strokeColor = UIColor.lightGray.cgColor
    shapeLayer.lineWidth = 1
    shapeLayer.lineDashPattern = [7, 3] // 7 is the length of dash, 3 is length of the gap.

    let path = CGMutablePath()
    path.addLines(between: [p0, p1])
    shapeLayer.path = path
    view.layer.addSublayer(shapeLayer)
}

通话功能

drawDottedLine(start: CGPoint(x: dashedView.bounds.minX, y: dashedView.bounds.minY), end: CGPoint(x: dashedView.bounds.maxX, y: dashedView.bounds.minY), view: dashedView)

使用上面你将有一条直线，你也可以根据需要改变点，例如，如果你将终点的y从dashedView.bounds.minY改为dashedView.bounds.maxY，你就会有对角线。

如果您将在UIView的子类中使用它，您将没有插座，因此您将使用它与self。

Answer 3

SWIFT 4.2非常简单的UIView扩展：

extension UIView {
    private static let lineDashPattern: [NSNumber] = [2, 2]
    private static let lineDashWidth: CGFloat = 1.0

    func makeDashedBorderLine() {
        let path = CGMutablePath()
        let shapeLayer = CAShapeLayer()
        shapeLayer.lineWidth = UIView.lineDashWidth
        shapeLayer.strokeColor = UIColor.lightGray.cgColor
        shapeLayer.lineDashPattern = UIView.lineDashPattern
        path.addLines(between: [CGPoint(x: bounds.minX, y: bounds.height/2),
                                CGPoint(x: bounds.maxX, y: bounds.height/2)])
        shapeLayer.path = path
        layer.addSublayer(shapeLayer)
    }
}

Answer 4

通过使用自定义类继承自UIView也支持Storyboard。

您需要做的就是在故事板中为该视图分配类，并在故事板中查看魔术。

@IBDesignable
class DashedLineView : UIView {
    @IBInspectable var perDashLength: CGFloat = 2.0
    @IBInspectable var spaceBetweenDash: CGFloat = 2.0
    @IBInspectable var dashColor: UIColor = UIColor.lightGray


    override func draw(_ rect: CGRect) {
        super.draw(rect)
        let  path = UIBezierPath()
        if height > width {
            let  p0 = CGPoint(x: self.bounds.midX, y: self.bounds.minY)
            path.move(to: p0)

            let  p1 = CGPoint(x: self.bounds.midX, y: self.bounds.maxY)
            path.addLine(to: p1)
            path.lineWidth = width

        } else {
            let  p0 = CGPoint(x: self.bounds.minX, y: self.bounds.midY)
            path.move(to: p0)

            let  p1 = CGPoint(x: self.bounds.maxX, y: self.bounds.midY)
            path.addLine(to: p1)
            path.lineWidth = height
        }

        let  dashes: [ CGFloat ] = [ perDashLength, spaceBetweenDash ]
        path.setLineDash(dashes, count: dashes.count, phase: 0.0)

        path.lineCapStyle = .butt
        dashColor.set()
        path.stroke()
    }

    private var width : CGFloat {
        return self.bounds.width
    }

    private var height : CGFloat {
        return self.bounds.height
    }
}

Answer 5

我的扩展方法是从@FanJins建立的

extension UIView {

    func createDashedLine(from point1: CGPoint, to point2: CGPoint, color: UIColor, strokeLength: NSNumber, gapLength: NSNumber, width: CGFloat) {
        let shapeLayer = CAShapeLayer()

        shapeLayer.strokeColor = color.cgColor
        shapeLayer.lineWidth = width
        shapeLayer.lineDashPattern = [strokeLength, gapLength]

        let path = CGMutablePath()
        path.addLines(between: [point1, point2])
        shapeLayer.path = path
        layer.addSublayer(shapeLayer)
    }
}

然后调用方法看起来像这样：

let topPoint = CGPoint(x: view.frame.midX, y: view.bounds.minY)
let bottomPoint = CGPoint(x: view.frame.midX, y: view.bounds.maxY)

view.createDashedLine(from: topPoint, to: bottomPoint, color: .black, strokeLength: 4, gapLength: 6, width: 2)

Answer 6

目标C. @ user3230875回答帮助我理解绘制虚线所需的内容。 所以我希望这个答案可以帮助一个Obj-C寻求者

//dashed line
    path = [UIBezierPath bezierPath];
    [path moveToPoint:CGPointMake(dashedLineStartX, dashedLineStartY)];
    [path addLineToPoint:CGPointMake(dashedLineEndX, dashedLineEndY)];
    path.lineWidth = 5;
    [color setStroke];
    CGFloat dashes[] = {4.0,8.0};
    [path setLineDash:dashes count:2 phase:0.0];
    path.lineCapStyle = kCGLineCapButt;
    [path stroke];