在2017年使用IBDesignable绘制虚线（不是虚线！）线

时间：2014-09-24 13:34:38

标签： ios swift uiview uikit

使用UIKit绘制虚线线很容易。所以：

CGFloat dashes[] = {4, 2};
[path setLineDash:dashes count:2 phase:0];
[path stroke];

enter image description here

有没有办法画出真正的虚线？

enter image description here

有什么想法吗？

由于这个问题很老，而且没有人提出完整的@IBDesignable解决方案，这里就是......

希望能节省一些人的打字。

@IBDesignable class DottedVertical: UIView {

    @IBInspectable var dotColor: UIColor = UIColor.etc
    @IBInspectable var lowerHalfOnly: Bool = false

    override func draw(_ rect: CGRect) {

        // say you want 8 dots, with perfect fenceposting:
        let totalCount = 8 + 8 - 1
        let fullHeight = bounds.size.height
        let width = bounds.size.width
        let itemLength = fullHeight / CGFloat(totalCount)

        let path = UIBezierPath()

        let beginFromTop = CGFloat(0.0)
        let top = CGPoint(x: width/2, y: beginFromTop)
        let bottom = CGPoint(x: width/2, y: fullHeight)

        path.move(to: top)
        path.addLine(to: bottom)

        path.lineWidth = width

        let dashes: [CGFloat] = [itemLength, itemLength]
        path.setLineDash(dashes, count: dashes.count, phase: 0)

        // for ROUNDED dots, simply change to....
        //let dashes: [CGFloat] = [0.0, itemLength * 2.0]
        //path.lineCapStyle = CGLineCap.round

        dotColor.setStroke()
        path.stroke()
    }
}

我让它垂直，你可以轻松改变。

enter image description here

只需在场景中放置一个UIView;使它成为你想要的任何宽度，这将是虚线的宽度。

只需将课程更改为DottedVertical，即可完成。它将在故事板中正确呈现。

enter image description here

请注意，为块的高度（＆＃34; totalCount＆＃34;等等...）给出的示例代码会使块完美地与像素匹配，与UIView的末端匹配。创造这条线。

请务必勾选下面的RobMayoff的答案，其中给出了两个不需要块的代码行。

10 个答案:

答案 0 :(得分：90)

将线帽样式设置为圆形，并将“on”长度设置为一个很小的数字。

Swift游乐场示例：

import UIKit
import PlaygroundSupport

let path = UIBezierPath()
path.move(to: CGPoint(x:10,y:10))
path.addLine(to: CGPoint(x:290,y:10))
path.lineWidth = 8

let dashes: [CGFloat] = [0.001, path.lineWidth * 2]
path.setLineDash(dashes, count: dashes.count, phase: 0)
path.lineCapStyle = CGLineCap.round

UIGraphicsBeginImageContextWithOptions(CGSize(width:300, height:20), false, 2)

UIColor.white.setFill()
UIGraphicsGetCurrentContext()!.fill(.infinite)

UIColor.black.setStroke()
path.stroke()

let image = UIGraphicsGetImageFromCurrentImageContext()
let view = UIImageView(image: image)
PlaygroundPage.current.liveView = view

UIGraphicsEndImageContext()

结果：

dots

对于objective-C，使用与问题中相同的示例类，只需添加

即可 
CGContextSetLineCap(cx, kCGLineCapRound);
在调用CGContextStrokePath之前

，并更改ra数组值以匹配我的Swift代码。

答案 1 :(得分：13)

上面Swift示例的Objective-C版本：

UIBezierPath * path = [[UIBezierPath alloc] init];
[path moveToPoint:CGPointMake(10.0, 10.0)];
[path addLineToPoint:CGPointMake(290.0, 10.0)];
[path setLineWidth:8.0];
CGFloat dashes[] = { path.lineWidth, path.lineWidth * 2 };
[path setLineDash:dashes count:2 phase:0];
[path setLineCapStyle:kCGLineCapRound];
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 20), false, 2);
[path stroke];
UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

答案 2 :(得分：11)

使用与Swift 3.0兼容的UIView扩展，以下内容应该有效：

extension UIView {

    func addDashedBorder(strokeColor: UIColor, lineWidth: CGFloat) {
        self.layoutIfNeeded()
        let strokeColor = strokeColor.cgColor

        let shapeLayer:CAShapeLayer = CAShapeLayer()
        let frameSize = self.frame.size
        let shapeRect = CGRect(x: 0, y: 0, width: frameSize.width, height: frameSize.height)

        shapeLayer.bounds = shapeRect
        shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.strokeColor = strokeColor
        shapeLayer.lineWidth = lineWidth
        shapeLayer.lineJoin = kCALineJoinRound

        shapeLayer.lineDashPattern = [5,5] // adjust to your liking
        shapeLayer.path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: shapeRect.width, height: shapeRect.height), cornerRadius: self.layer.cornerRadius).cgPath

        self.layer.addSublayer(shapeLayer)
    }

}

然后在viewDidLoad之后运行的函数中，如viewDidLayoutSubviews，在相关视图上运行addDashedBorder函数：

class ViewController: UIViewController {

    var someView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        someView = UIView()
        someView.layer.cornerRadius = 5.0

        view.addSubview(someView)

        someView.translatesAutoresizingMaskIntoConstraints = false
        someView.widthAnchor.constraint(equalToConstant: 200).isActive = true
        someView.heightAnchor.constraint(equalToConstant: 200).isActive = true
        someView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        someView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
    }

    override func viewDidLayoutSubviews() {
        someView.addDashedBorder(strokeColor: UIColor.red, lineWidth: 1.0)
    }

}

答案 3 :(得分：3)

我在rob mayoff上接受了一些解决方案，可以轻松自定义虚线：

  • 更改每个圆的半径。
  • 更改2个圆圈之间的空格数。
  • 更改要生成的模式数。

该函数返回UIImage：

extension UIImage {

    class func dottedLine(radius radius: CGFloat, space: CGFloat, numberOfPattern: CGFloat) -> UIImage {


        let path = UIBezierPath()
        path.moveToPoint(CGPointMake(radius/2, radius/2))
        path.addLineToPoint(CGPointMake((numberOfPattern)*(space+1)*radius, radius/2))
        path.lineWidth = radius

        let dashes: [CGFloat] = [path.lineWidth * 0, path.lineWidth * (space+1)]
        path.setLineDash(dashes, count: dashes.count, phase: 0)
        path.lineCapStyle = CGLineCap.Round


        UIGraphicsBeginImageContextWithOptions(CGSizeMake((numberOfPattern)*(space+1)*radius, radius), false, 1)
        UIColor.whiteColor().setStroke()
        path.stroke()
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image

    }
}

以下是获取图片的方法：

UIImage.dottedLine(radius: 100, space: 2, numberOfPattern: 1)

答案 4 :(得分：3)

大家好，这个解决方案对我很有用。我找到了某个地方，并改变了一点，以防止控制台警告。 

extension UIImage {
    static func drawDottedImage(width: CGFloat, height: CGFloat, color: UIColor) -> UIImage {
        let path = UIBezierPath()
        path.move(to: CGPoint(x: 1.0, y: 1.0))
        path.addLine(to: CGPoint(x: width, y: 1))
        path.lineWidth = 1.5           
        let dashes: [CGFloat] = [path.lineWidth, path.lineWidth * 5]
        path.setLineDash(dashes, count: 2, phase: 0)
        path.lineCapStyle = .butt
        UIGraphicsBeginImageContextWithOptions(CGSize(width: width, height: height), false, 2)
        color.setStroke()
        path.stroke()

        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()

        return image
    }
}

结果如下：

result

答案 5 :(得分：2)

不是一个完整的答案，只是一个非常重要的问题，James P在最喜欢的答案评论中提出：

他写道：

  

我发现将长度设置为 0.01 会给你一个圆点，   而使用0时它们会略微拉长。

例如，

   let dashes: [CGFloat] = [0.001, path.lineWidth * 2]

答案 6 :(得分：0)

在swift 3.1中，您可以使用以下代码：

context.setLineCap(.round)

有三种风格：

 /* Line cap styles. */

public enum CGLineCap : Int32 {

    case butt

    case round

    case square
}

答案 7 :(得分：0)

可以正常使用以下代码，

layer.path = linePath.cgPath
layer.lineWidth = 3
layer.lineDashPattern = [1,layer.lineWidth*2] as [NSNumber]
layer.lineCap = "round"

答案 8 :(得分：0)

嘿，现在回答这个问题可能为时已晚。但是，如果您同意，我想与一个简单的方法分享给将来可能会遇到该问题的开发人员。所以我想这是使用@IBDesignable的最简单解决方案。您只需要创建该类

import UIKit

@IBDesignable class DottedVertical: UIView {

    @IBInspectable var dotColor: UIColor = UIColor.red
    @IBInspectable var lowerHalfOnly: Bool = false

    override func draw(_ rect: CGRect) {

        // say you want 8 dots, with perfect fenceposting:
        let totalCount = 8 + 8 - 1
        let fullHeight = bounds.size.height
        let width = bounds.size.width
        let itemLength = fullHeight / CGFloat(totalCount)

        let path = UIBezierPath()

        let beginFromTop = CGFloat(0.0)
        let top = CGPoint(x: width/2, y: beginFromTop)
        let bottom = CGPoint(x: width/2, y: fullHeight)

        path.move(to: top)
        path.addLine(to: bottom)

        path.lineWidth = width
        //DASHED SIMPLE LINE
        //let dashes: [CGFloat] = [itemLength, itemLength]
        //path.setLineDash(dashes, count: dashes.count, phase: 0)

        // for ROUNDED dots, simply change to....
        let dashes: [CGFloat] = [0.0, itemLength * 1.1]
        path.lineCapStyle = CGLineCap.round
        path.setLineDash(dashes, count: dashes.count, phase: 0)

        dotColor.setStroke()
        path.stroke()
    }
}

然后将其附加到情节提要中的视图中 enter image description here

完成后，请从DottedVertical类的此行let dashes: [CGFloat] = [0.0, itemLength * 1.1]->第39行中冷自定义图层之间的空间。 或者，如果您想自定义图层的宽度，则只需在情节提要中编辑线视图的宽度即可

答案 9 :(得分：-1)

我已经在titleLabel中UILabel（viewDidAppear）的底部添加了以下代码来添加带有虚线样式的边框：

CAShapeLayer *shapelayer = [CAShapeLayer layer];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0.0, titileLabel.frame.size.height-2)];
[path addLineToPoint:CGPointMake(SCREEN_WIDTH, titileLabel.frame.size.height-2)];
UIColor *fill = [UIColor colorWithRed:0.80f green:0.80f blue:0.80f alpha:1.00f];
shapelayer.strokeStart = 0.0;
shapelayer.strokeColor = fill.CGColor;
shapelayer.lineWidth = 2.0;
shapelayer.lineJoin = kCALineJoinRound;
shapelayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:2],[NSNumber numberWithInt:3 ], nil];
shapelayer.path = path.CGPath;

[titileLabel.layer addSublayer:shapelayer];

参考：https://gist.github.com/kaiix/4070967

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