如何在iPhone上绘制"漫画气泡"?

Question

如何在iPhone上绘制"漫画气泡"?

iosobjective-ciphoneuiviewuibezierpath

52

我正在尝试实现一个“聊天气泡”的效果，类似于在Mac OS X中在dock上右键单击某个项目时出现的效果。这是我现在拥有的：

alt text

我需要获得下部分的“三角形”部分。是否有任何方法可以绘制类似的东西并获得其周围的边框？这将用于一个iPhone应用程序。

提前感谢！

编辑：非常感谢Brad Larson，现在它看起来像这样： alt text

- sudo rm -rf

12个回答

16

我在这里寻找一个在现有视图中绘制“箭头”的解决方案。
很高兴与您分享一些代码，我希望它有用 - 与Swift 2.3兼容 -

public extension UIView {

  public enum PeakSide: Int {
        case Top
        case Left
        case Right
        case Bottom
    }

    public func addPikeOnView(side side: PeakSide, size: CGFloat = 10.0) {
        self.layoutIfNeeded()
        let peakLayer = CAShapeLayer()
        var path: CGPathRef?
        switch side {
        case .Top:
            path = self.makePeakPathWithRect(self.bounds, topSize: size, rightSize: 0.0, bottomSize: 0.0, leftSize: 0.0)
        case .Left:
            path = self.makePeakPathWithRect(self.bounds, topSize: 0.0, rightSize: 0.0, bottomSize: 0.0, leftSize: size)
        case .Right:
            path = self.makePeakPathWithRect(self.bounds, topSize: 0.0, rightSize: size, bottomSize: 0.0, leftSize: 0.0)
        case .Bottom:
            path = self.makePeakPathWithRect(self.bounds, topSize: 0.0, rightSize: 0.0, bottomSize: size, leftSize: 0.0)
        }
        peakLayer.path = path
        let color = (self.backgroundColor ?? .clearColor()).CGColor
        peakLayer.fillColor = color
        peakLayer.strokeColor = color
        peakLayer.lineWidth = 1
        peakLayer.position = CGPoint.zero
        self.layer.insertSublayer(peakLayer, atIndex: 0)
    }


    func makePeakPathWithRect(rect: CGRect, topSize ts: CGFloat, rightSize rs: CGFloat, bottomSize bs: CGFloat, leftSize ls: CGFloat) -> CGPathRef {
        //                      P3
        //                    /    \
        //      P1 -------- P2     P4 -------- P5
        //      |                               |
        //      |                               |
        //      P16                            P6
        //     /                                 \
        //  P15                                   P7
        //     \                                 /
        //      P14                            P8
        //      |                               |
        //      |                               |
        //      P13 ------ P12    P10 -------- P9
        //                    \   /
        //                     P11

        let centerX = rect.width / 2
        let centerY = rect.height / 2
        var h: CGFloat = 0
        let path = CGPathCreateMutable()
        var points: [CGPoint] = []
        // P1
        points.append(CGPointMake(rect.origin.x, rect.origin.y))
        // Points for top side
        if ts > 0 {
            h = ts * sqrt(3.0) / 2
            let x = rect.origin.x + centerX
            let y = rect.origin.y
            points.append(CGPointMake(x - ts, y))
            points.append(CGPointMake(x, y - h))
            points.append(CGPointMake(x + ts, y))
        }

        // P5
        points.append(CGPointMake(rect.origin.x + rect.width, rect.origin.y))
        // Points for right side
        if rs > 0 {
            h = rs * sqrt(3.0) / 2
            let x = rect.origin.x + rect.width
            let y = rect.origin.y + centerY
            points.append(CGPointMake(x, y - rs))
            points.append(CGPointMake(x + h, y))
            points.append(CGPointMake(x, y + rs))
        }

        // P9
        points.append(CGPointMake(rect.origin.x + rect.width, rect.origin.y + rect.height))
        // Point for bottom side
        if bs > 0 {
            h = bs * sqrt(3.0) / 2
            let x = rect.origin.x + centerX
            let y = rect.origin.y + rect.height
            points.append(CGPointMake(x + bs, y))
            points.append(CGPointMake(x, y + h))
            points.append(CGPointMake(x - bs, y))
        }

        // P13
        points.append(CGPointMake(rect.origin.x, rect.origin.y + rect.height))
        // Point for left side
        if ls > 0 {
            h = ls * sqrt(3.0) / 2
            let x = rect.origin.x
            let y = rect.origin.y + centerY
            points.append(CGPointMake(x, y + ls))
            points.append(CGPointMake(x - h, y))
            points.append(CGPointMake(x, y - ls))
        }

        let startPoint = points.removeFirst()
        self.startPath(path: path, onPoint: startPoint)
        for point in points {
            self.addPoint(point, toPath: path)
        }
        self.addPoint(startPoint, toPath: path)
        return path
    }

    private func startPath(path path: CGMutablePath, onPoint point: CGPoint) {
        CGPathMoveToPoint(path, nil, point.x, point.y)
    }

    private func addPoint(point: CGPoint, toPath path: CGMutablePath) {
        CGPathAddLineToPoint(path, nil, point.x, point.y)
    }

}

通过这种方式，您可以针对任何类型的视图调用此函数：

let view = UIView(frame: frame)
view.addPikeOnView(side: .Top)

未来我将为长矛的位置添加偏移量。

是的，名称绝对可以改进！

SWIFT 3 版本

public extension UIView {

    public enum PeakSide: Int {
        case Top
        case Left
        case Right
        case Bottom
    }

    public func addPikeOnView( side: PeakSide, size: CGFloat = 10.0) {
        self.layoutIfNeeded()
        let peakLayer = CAShapeLayer()
        var path: CGPath?
        switch side {
        case .Top:
            path = self.makePeakPathWithRect(rect: self.bounds, topSize: size, rightSize: 0.0, bottomSize: 0.0, leftSize: 0.0)
        case .Left:
            path = self.makePeakPathWithRect(rect: self.bounds, topSize: 0.0, rightSize: 0.0, bottomSize: 0.0, leftSize: size)
        case .Right:
            path = self.makePeakPathWithRect(rect: self.bounds, topSize: 0.0, rightSize: size, bottomSize: 0.0, leftSize: 0.0)
        case .Bottom:
            path = self.makePeakPathWithRect(rect: self.bounds, topSize: 0.0, rightSize: 0.0, bottomSize: size, leftSize: 0.0)
        }
        peakLayer.path = path
        let color = (self.backgroundColor?.cgColor)
        peakLayer.fillColor = color
        peakLayer.strokeColor = color
        peakLayer.lineWidth = 1
        peakLayer.position = CGPoint.zero
        self.layer.insertSublayer(peakLayer, at: 0)
    }


    func makePeakPathWithRect(rect: CGRect, topSize ts: CGFloat, rightSize rs: CGFloat, bottomSize bs: CGFloat, leftSize ls: CGFloat) -> CGPath {
        //                      P3
        //                    /    \
        //      P1 -------- P2     P4 -------- P5
        //      |                               |
        //      |                               |
        //      P16                            P6
        //     /                                 \
        //  P15                                   P7
        //     \                                 /
        //      P14                            P8
        //      |                               |
        //      |                               |
        //      P13 ------ P12    P10 -------- P9
        //                    \   /
        //                     P11

        let centerX = rect.width / 2
        let centerY = rect.height / 2
        var h: CGFloat = 0
        let path = CGMutablePath()
        var points: [CGPoint] = []
        // P1
        points.append(CGPoint(x:rect.origin.x,y: rect.origin.y))
        // Points for top side
        if ts > 0 {
            h = ts * sqrt(3.0) / 2
            let x = rect.origin.x + centerX
            let y = rect.origin.y
            points.append(CGPoint(x:x - ts,y: y))
            points.append(CGPoint(x:x,y: y - h))
            points.append(CGPoint(x:x + ts,y: y))
       }

        // P5
        points.append(CGPoint(x:rect.origin.x + rect.width,y: rect.origin.y))
        // Points for right side
        if rs > 0 {
            h = rs * sqrt(3.0) / 2
            let x = rect.origin.x + rect.width
           let y = rect.origin.y + centerY
           points.append(CGPoint(x:x,y: y - rs))
           points.append(CGPoint(x:x + h,y: y))
           points.append(CGPoint(x:x,y: y + rs))
        }

        // P9
        points.append(CGPoint(x:rect.origin.x + rect.width,y: rect.origin.y + rect.height))
        // Point for bottom side
        if bs > 0 {
            h = bs * sqrt(3.0) / 2
            let x = rect.origin.x + centerX
            let y = rect.origin.y + rect.height
            points.append(CGPoint(x:x + bs,y: y))
            points.append(CGPoint(x:x,y: y + h))
            points.append(CGPoint(x:x - bs,y: y))
        }

        // P13
        points.append(CGPoint(x:rect.origin.x, y: rect.origin.y + rect.height))
        // Point for left sidey:
        if ls > 0 {
            h = ls * sqrt(3.0) / 2
            let x = rect.origin.x
            let y = rect.origin.y + centerY
            points.append(CGPoint(x:x,y: y + ls))
            points.append(CGPoint(x:x - h,y: y))
            points.append(CGPoint(x:x,y: y - ls))
        }

        let startPoint = points.removeFirst()
        self.startPath(path: path, onPoint: startPoint)
        for point in points {
            self.addPoint(point: point, toPath: path)
        }
        self.addPoint(point: startPoint, toPath: path)
        return path
    }

    private func startPath( path: CGMutablePath, onPoint point: CGPoint) {
        path.move(to: CGPoint(x: point.x, y: point.y))
    }

    private func addPoint(point: CGPoint, toPath path: CGMutablePath) {
       path.addLine(to: CGPoint(x: point.x, y: point.y))
    }
}

- Luca Davanzo

谢谢！有没有办法在UIView上添加一些peak和clipToBounds的方式？ - ClockWise

嗨，我需要以下图像中的P15侧箭头。请帮助我。 - Prissy Eve

1

@Luca Davanzo，它可以工作，但有一个问题，如何将角落变圆？如果我设置cornerRadius = 7，然后masksToBounds = true，我会失去尖角。但是，如果我不设置masksToBounds，我会保留尖角，但失去圆角。 - Lance Samaria

15

用Swift 2编写创建UIBezierPath的代码：

var borderWidth : CGFloat = 4 // Should be less or equal to the `radius` property
var radius : CGFloat = 10
var triangleHeight : CGFloat = 15

private func bubblePathForContentSize(contentSize: CGSize) -> UIBezierPath {
    let rect = CGRectMake(0, 0, contentSize.width, contentSize.height).offsetBy(dx: radius, dy: radius + triangleHeight)
    let path = UIBezierPath();
    let radius2 = radius - borderWidth / 2 // Radius adjasted for the border width

    path.moveToPoint(CGPointMake(rect.maxX - triangleHeight * 2, rect.minY - radius2))
    path.addLineToPoint(CGPointMake(rect.maxX - triangleHeight, rect.minY - radius2 - triangleHeight))
    path.addArcWithCenter(CGPointMake(rect.maxX, rect.minY), radius: radius2, startAngle: CGFloat(-M_PI_2), endAngle: 0, clockwise: true)
    path.addArcWithCenter(CGPointMake(rect.maxX, rect.maxY), radius: radius2, startAngle: 0, endAngle: CGFloat(M_PI_2), clockwise: true)
    path.addArcWithCenter(CGPointMake(rect.minX, rect.maxY), radius: radius2, startAngle: CGFloat(M_PI_2), endAngle: CGFloat(M_PI), clockwise: true)
    path.addArcWithCenter(CGPointMake(rect.minX, rect.minY), radius: radius2, startAngle: CGFloat(M_PI), endAngle: CGFloat(-M_PI_2), clockwise: true)
    path.closePath()
    return path
}

现在，您可以使用此路径进行任何操作。例如，将其与CAShapeLayer一起使用：

let bubbleLayer = CAShapeLayer()
bubbleLayer.path = bubblePathForContentSize(contentView.bounds.size).CGPath
bubbleLayer.fillColor = fillColor.CGColor
bubbleLayer.strokeColor = borderColor.CGColor
bubbleLayer.lineWidth = borderWidth
bubbleLayer.position = CGPoint.zero
myView.layer.addSublayer(bubbleLayer)

- Avt

13

也许一个更简单的问题是“是否已经有代码可以为我完成这个”，答案是“是的”。请看MAAttachedWindow： alt text

当然，你可能不想要整个“附加窗口”的行为，但至少绘图代码已经存在。(而且Matt Gemmell的代码质量很高)

- Dave DeLong

6

马特的MAAttachedWindow是Mac上很棒的组件，但根据标签，我认为他正在寻找在iPhone上也能使用的组件。 - Brad Larson

没错，看起来很不错，但是...我正在寻找一种在iPhone上实现这个的方法。我会更新我的标题... - sudo rm -rf

4

@sudo @Brad 确实这是给 Mac 设计的，但是他所使用的代码很容易适用于 iPhone；只需将 NSMakePoint 替换为 CGPointMake，NSBezierPath 替换为 UIBezierPath，就几乎完成了。 - Dave DeLong

7

有两种方法可以实现此目的：

添加一个UIImageView，并在正确的位置放置一个三角形图像。确保图像的其余部分是透明的，以免阻挡背景。
覆盖您的UIView上的drawRect:方法以自定义绘制视图。然后，您可以添加线性路径组件来绘制三角形，根据需要填充和边框路径。

要使用drawRect：绘制简单的三角形，您可以像这样做。此代码段将在您视图的底部绘制一个指向下方的三角形。

// Get the context
CGContextRef context = UIGraphicsGetCurrentContext();

// Pick colors
CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);

// Define triangle dimensions
CGFloat baseWidth = 30.0;
CGFloat height = 20.0;

// Define path
CGContextMoveToPoint(context, self.bounds.size.width / 2.0 - baseWidth / 2.0, 
                              self.bounds.size.height - height);
CGContextAddLineToPoint(context, self.bounds.size.width / 2.0 + baseWidth / 2.0, 
                                 self.bounds.size.height - height);
CGContextAddLineToPoint(context, self.bounds.size.width / 2.0, 
                                 self.bounds.size.height);

// Finalize and draw using path
CGContextClosePath(context);
CGContextStrokePath(context);

更多信息请参见CGContext参考。

- Tim

2

尝试将最后一行更改为 CGContextDrawPath(context, kCGPathFillStroke); 以填充和描边。 - user467105

我在Xcode中运行了这个程序，并在我的视图中看到了一个黑色的三角形，所以我不确定你遇到了什么问题 - 你能描述一下你使用的视图层次结构和子类吗？ - Tim

@Tim，好的，我成功让它显示了。但是，我无法填充它。我尝试使用CGContextFillPath（context）和CGContextDrawPath（context，kCGPathFillStroke），但我仍然得到这个：http://i.imgur.com/y99nt.png 我正在创建一个新的视图，使用drawRect：（CGRect）rect绘制一个三角形，该三角形位于我绘制的另一个矩形下方。 - sudo rm -rf

你确定在调用 CGContextFillPath（） 之前设置了填充颜色吗？ - Tim

对于那些无法显示任何内容的人，你的类必须是“UIView”，而不是“UIImageView”。我是通过艰难的方式学到这一点的 ;) - Jason Leung

显示剩余2条评论

3

如果你使用的是基于 Brad Larson 的答案的 Swift 2.0 技术

override func drawRect(rect: CGRect) {
    super.drawRect(rect) // optional if a direct UIView-subclass, should be called otherwise.

    let HEIGHTOFPOPUPTRIANGLE:CGFloat = 20.0
    let WIDTHOFPOPUPTRIANGLE:CGFloat = 40.0
    let borderRadius:CGFloat = 8.0
    let strokeWidth:CGFloat = 3.0

    // Get the context
    let context: CGContextRef = UIGraphicsGetCurrentContext()!
    CGContextTranslateCTM(context, 0.0, self.bounds.size.height)
    CGContextScaleCTM(context, 1.0, -1.0)
    //
    let currentFrame: CGRect = self.bounds
    CGContextSetLineJoin(context, CGLineJoin.Round)
    CGContextSetLineWidth(context, strokeWidth)
    CGContextSetStrokeColorWithColor(context, UIColor.whiteColor().CGColor)
    CGContextSetFillColorWithColor(context, UIColor.blackColor().CGColor)
    // Draw and fill the bubble
    CGContextBeginPath(context)
    CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5)
    CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0 - WIDTHOFPOPUPTRIANGLE / 2.0) + 0.5, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5)
    CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0) + 0.5, strokeWidth + 0.5)
    CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) + 0.5, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5)
    CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5, currentFrame.size.width - strokeWidth - 0.5, currentFrame.size.height - strokeWidth - 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5, currentFrame.size.height - strokeWidth - 0.5, round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) - strokeWidth + 0.5, currentFrame.size.height - strokeWidth - 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, strokeWidth + 0.5, currentFrame.size.height - strokeWidth - 0.5, strokeWidth + 0.5, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, strokeWidth + 0.5, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5, currentFrame.size.width - strokeWidth - 0.5, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5, borderRadius - strokeWidth)
    CGContextClosePath(context)
    CGContextDrawPath(context, CGPathDrawingMode.FillStroke)

    // Draw a clipping path for the fill
    CGContextBeginPath(context)
    CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5)
    CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5, currentFrame.size.width - strokeWidth - 0.5, currentFrame.size.height - strokeWidth - 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5, currentFrame.size.height - strokeWidth - 0.5, round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) - strokeWidth + 0.5, currentFrame.size.height - strokeWidth - 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, strokeWidth + 0.5, currentFrame.size.height - strokeWidth - 0.5, strokeWidth + 0.5, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5, borderRadius - strokeWidth)
    CGContextAddArcToPoint(context, strokeWidth + 0.5, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5, currentFrame.size.width - strokeWidth - 0.5, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5, borderRadius - strokeWidth)
    CGContextClosePath(context)
    CGContextClip(context)
}

- kdgwill

2

这是一个Swift 5版本的@IBDesignable UIView

@IBDesignable
class SpeechBubble: UIView {

@IBInspectable var lineWidth: CGFloat = 4 { didSet { setNeedsDisplay() } }
@IBInspectable var cornerRadius: CGFloat = 8 { didSet { setNeedsDisplay() } }

@IBInspectable var strokeColor: UIColor = .red { didSet { setNeedsDisplay() } }
@IBInspectable var fillColor: UIColor = .gray { didSet { setNeedsDisplay() } }

@IBInspectable var peakWidth: CGFloat  = 10 { didSet { setNeedsDisplay() } }
@IBInspectable var peakHeight: CGFloat = 10 { didSet { setNeedsDisplay() } }
@IBInspectable var peakOffset: CGFloat = 0 { didSet { setNeedsDisplay() } }

override func draw(_ rectangle: CGRect) {
    
    //Add a bounding area so we can fit the peak in the view
    let rect = bounds.insetBy(dx: peakHeight, dy: peakHeight)
    
    let centerX = rect.width / 2
    //let centerY = rect.height / 2
    var h: CGFloat = 0
    
    //create the path
    let path = UIBezierPath()
    path.lineWidth = lineWidth
    
    // Start of bubble (Top Left)
    path.move(to: CGPoint(x: rect.minX, y: rect.minY + cornerRadius))
    path.addQuadCurve(to: CGPoint(x: rect.minX + cornerRadius, y: rect.minY),
                      controlPoint: CGPoint(x: rect.minX, y: rect.minY))
    
    //Add the peak
    h = peakHeight * sqrt(3.0) / 2

    let x = rect.origin.x + centerX
    let y = rect.origin.y
    path.addLine(to: CGPoint(x: (x + peakOffset) - peakWidth, y: y))
    path.addLine(to: CGPoint(x: (x + peakOffset), y: y - h))
    path.addLine(to: CGPoint(x: (x + peakOffset) + peakWidth, y: y))
    
    // Top Right
    path.addLine(to: CGPoint(x: rect.maxX - cornerRadius, y: rect.minY))
    path.addQuadCurve(to: CGPoint(x: rect.maxX, y: rect.minY + cornerRadius),
                      controlPoint: CGPoint(x: rect.maxX, y: rect.minY))
    
    // Bottom Right
    path.addLine(to: CGPoint(x: rect.maxX, y: rect.maxY - cornerRadius))
    path.addQuadCurve(to: CGPoint(x: rect.maxX - cornerRadius, y: rect.maxY),
                      controlPoint: CGPoint(x: rect.maxX, y: rect.maxY))
    //Bottom Left
    path.addLine(to: CGPoint(x: rect.minX + cornerRadius, y: rect.maxY))
    path.addQuadCurve(to: CGPoint(x: rect.minX, y: rect.maxY - cornerRadius), controlPoint: CGPoint(x: rect.minX, y: rect.maxY))
    // Back to start
    path.addLine(to: CGPoint(x: rect.origin.x, y: rect.minY + cornerRadius))
    
    //set and draw stroke color
    strokeColor.setStroke()
    path.stroke()
    
    //set and draw fill color
    fillColor.setFill()
    path.fill()
    
  }
}

- Blain Ellis

1

Swift 4 更新

这是 AVT 原始代码的 Swift 4 版本。

 private func bubblePathForContentSize(contentSize: CGSize) -> UIBezierPath {
    let rect = CGRect(origin: .zero, size: CGSize(width: contentSize.width, height: contentSize.height)).offsetBy(dx: radius, dy: radius + triangleHeight)
    let path = UIBezierPath();
    let radius2 = radius - borderWidth / 2 // Radius adjasted for the border width

    path.move(to: CGPoint(x: rect.maxX - triangleHeight * 2, y: rect.minY - radius2))
    path.addLine(to: CGPoint(x: rect.maxX - triangleHeight, y: rect.minY - radius2 - triangleHeight))
    path.addArc(withCenter: CGPoint(x: rect.maxX, y: rect.minY),
                radius: radius2,
                startAngle: CGFloat(-(Double.pi/2)), endAngle: 0, clockwise: true)
    path.addArc(withCenter: CGPoint(x: rect.maxX, y: rect.maxY),
                radius: radius2,
                startAngle: 0, endAngle: CGFloat(Double.pi/2), clockwise: true)
    path.addArc(withCenter: CGPoint(x: rect.minX, y: rect.maxY),
                radius: radius2,
                startAngle: CGFloat(Double.pi/2),endAngle: CGFloat(Double.pi), clockwise: true)
    path.addArc(withCenter: CGPoint(x: rect.minX, y: rect.minY),
                radius: radius2,
                startAngle: CGFloat(Double.pi), endAngle: CGFloat(-(Double.pi/2)), clockwise: true)
    path.close()
    return path
}

//Example usage:
 let bubbleLayer = CAShapeLayer()
 bubbleLayer.path = bubblePathForContentSize(contentView.bounds.size).CGPath
 bubbleLayer.fillColor = fillColor.CGColor
 bubbleLayer.strokeColor = borderColor.CGColor
 bubbleLayer.lineWidth = borderWidth
 bubbleLayer.position = CGPoint.zero
 myView.layer.addSublayer(bubbleLayer)

- James Jordan Taylor

1

在下面的图像中，弹出菜单上的三角形是用核心图形函数绘制的，并且可以完全缩放。

alt text

这样做可以画出等边三角形（旧式函数名称，抱歉）：

#define triH(v) (v * 0.866)    

func(CGContextRef inContext, CGRect arrowRect, CustomPushButtonData* controlData) {
// Draw the triangle
float   arrowXstart, arrowYstart;
float   arrowXpos, arrowYpos, arrowHpos; 

if (controlData->controlEnabled && controlData->controlActive) {

    CGContextSetRGBFillColor(inContext, 0., 0., 0., 1.);

} else {

    CGContextSetRGBFillColor(inContext, 0., 0., 0., 0.5);

}

arrowHpos = triH(arrowRect.size.height);

// Point C

CGContextBeginPath(inContext);

arrowXstart = arrowXpos = (arrowRect.origin.x + ((float)(arrowRect.size.width / 2.) - (arrowSize / 2.)));

arrowYstart = arrowYpos = (arrowRect.origin.y + (float)((arrowRect.size.height / 2.) - (float)(arrowHpos / 2.)));

CGContextMoveToPoint(inContext, arrowXpos, arrowYpos);

// Point A

arrowXpos += arrowSize;

CGContextAddLineToPoint(inContext, arrowXpos, arrowYpos);

// Point B

arrowYpos += arrowHpos;

arrowXpos -= (float)(arrowSize / 2.0);

CGContextAddLineToPoint(inContext, arrowXpos, arrowYpos);

// Point C
CGContextAddLineToPoint(inContext, arrowXstart, arrowYstart);

CGContextClosePath(inContext);

CGContextFillPath(inContext);

}

请注意，triH(x)函数是用于计算等边三角形高度的优化公式，例如 h = 1/2 * sqrt(3) * x。由于 1/2 * sqrt(3) 永远不会改变，我将其优化为该定义。

- ExitToShell

也许你想到了Cocoa，但是你提供的代码在iPhone上无法运行。它给我带来了很多错误。 - sudo rm -rf

0

如果有人寻找Swift 3的答案，这段代码可以解决问题！感谢在我之前为此做出贡献的人们，这是一段美妙的代码！

    let rRect = CGRect(x: start.x, y: start.y, width: defaultHeightWidth.0, height: defaultHeightWidth.1)


    context?.translateBy(x: 0, y: rRect.size.height - 3)
    context?.scaleBy(x: 1.0, y: -1.0)


    context?.setLineJoin(.bevel)
    context?.setLineWidth(strokeWidth)
    context?.setStrokeColor(UIColor.black.cgColor)
    context?.setFillColor(UIColor.white.cgColor)

    // draw and fill the bubble
    context?.beginPath()
    context?.move(to: CGPoint(x: borderRadius + strokeWidth + 0.5, y: strokeWidth + triangleHeight + 0.5))
    context?.addLine(to: CGPoint(x: round(rRect.size.width / 2.0 - triangleWidth / 2.0) + 0.5, y: triangleHeight + strokeWidth + 0.5))
    context?.addLine(to: CGPoint(x: round(rRect.size.width / 2.0) + 0.5, y: strokeWidth + 0.5))
    context?.addLine(to: CGPoint(x: round(rRect.size.width / 2.0 + triangleWidth / 2.0), y: triangleHeight + strokeWidth + 0.5))
    context?.addArc(tangent1End: CGPoint(x: rRect.size.width - strokeWidth - 0.5, y: strokeWidth + triangleHeight + 0.5), tangent2End: CGPoint(x: rRect.size.width - strokeWidth - 0.5, y: rRect.size.height - strokeWidth - 0.5), radius: borderRadius - strokeWidth)
    context?.addArc(tangent1End: CGPoint(x: rRect.size.width - strokeWidth - 0.5, y: rRect.size.height - strokeWidth - 0.5), tangent2End: CGPoint(x: round(rRect.size.width / 2.0 + triangleWidth / 2.0) - strokeWidth + 0.5, y: rRect.size.height - strokeWidth - 0.5), radius: borderRadius - strokeWidth)
    context?.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y: rRect.size.height - strokeWidth - 0.5), tangent2End: CGPoint(x: strokeWidth + 0.5, y: triangleHeight + strokeWidth + 0.5), radius: borderRadius - strokeWidth)
    context?.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y: strokeWidth + triangleHeight + 0.5), tangent2End: CGPoint(x: rRect.size.width - strokeWidth - 0.5, y: triangleHeight + strokeWidth + 0.5), radius: borderRadius - strokeWidth)
    context?.closePath()
    context?.drawPath(using: .fillStroke)

在我的情况下，triangleWidth = 10 和 triangleHeight = 5 用于比 OP 版本中小得多的视图。

- pbush25

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Brad Larson · Accepted Answer

我以前实际上画过这个形状（底部带有指向性三角形的圆角矩形）。我使用的Quartz绘图代码如下：

CGRect currentFrame = self.bounds;

CGContextSetLineJoin(context, kCGLineJoinRound);
CGContextSetLineWidth(context, strokeWidth);
CGContextSetStrokeColorWithColor(context, [MyPopupLayer popupBorderColor]); 
CGContextSetFillColorWithColor(context, [MyPopupLayer popupBackgroundColor]);

// Draw and fill the bubble
CGContextBeginPath(context);
CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5f, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5f);
CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f - WIDTHOFPOPUPTRIANGLE / 2.0f) + 0.5f, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5f);
CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f) + 0.5f, strokeWidth + 0.5f);
CGContextAddLineToPoint(context, round(currentFrame.size.width / 2.0f + WIDTHOFPOPUPTRIANGLE / 2.0f) + 0.5f, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5f);
CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, round(currentFrame.size.width / 2.0f + WIDTHOFPOPUPTRIANGLE / 2.0f) - strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, strokeWidth + 0.5f, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, strokeWidth + 0.5f, strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5f, borderRadius - strokeWidth);
CGContextClosePath(context);
CGContextDrawPath(context, kCGPathFillStroke);

// Draw a clipping path for the fill
CGContextBeginPath(context);
CGContextMoveToPoint(context, borderRadius + strokeWidth + 0.5f, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50f) + 0.5f);
CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50f) + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, currentFrame.size.width - strokeWidth - 0.5f, currentFrame.size.height - strokeWidth - 0.5f, round(currentFrame.size.width / 2.0f + WIDTHOFPOPUPTRIANGLE / 2.0f) - strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, strokeWidth + 0.5f, currentFrame.size.height - strokeWidth - 0.5f, strokeWidth + 0.5f, HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5f, borderRadius - strokeWidth);
CGContextAddArcToPoint(context, strokeWidth + 0.5f, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50f) + 0.5f, currentFrame.size.width - strokeWidth - 0.5f, round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50f) + 0.5f, borderRadius - strokeWidth);
CGContextClosePath(context);
CGContextClip(context);

如果您不打算使用渐变或其他比简单颜色更复杂的填充，则可以省略最后的剪切路径。