ios 如何在 iPhone 上画一个“泡泡”？
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时间：2020-08-30 18:18:05 来源:igfitidea点击:
How to draw a "speech bubble" on an iPhone?
提问by sudo rm -rf
I'm trying to get a "speech bubble" effect similar to the one in Mac OS X when you right click on something in the dock. Here's what I have now:
当您右键单击 Dock 中的某些内容时，我试图获得类似于 Mac OS X 中的“语音气泡”效果。这是我现在所拥有的：
I need to get the "triangle" part of the lower portion. Is there any way I can draw something like that and get a border around it? This will be for an iPhoneapp.
我需要得到下部的“三角形”部分。有什么办法可以画这样的东西并在它周围加上边框吗？这将用于iPhone应用程序。
Thanks in advance!
提前致谢！
EDIT: Many thanks to Brad Larson, here's what it looks like now:
编辑：非常感谢 Brad Larson，这是现在的样子：
回答by Brad Larson
I've actually drawn this exact shape before (rounded rectangle with a pointing triangle at the bottom). The Quartz drawing code that I used is as follows:
我之前实际上已经绘制了这个确切的形状（圆角矩形，底部有一个三角形）。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);
The clipping path at the end can be left out if you're not going to use a gradient or some other more fill that's more complex than a simple color.
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。
回答by Avt
Swift 2 code that creates UIBezierPath:
创建 UIBezierPath 的 Swift 2 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
}
Now you could do whatever you want with this path. For example use it with CAShapeLayer:
现在你可以用这条路做任何你想做的事。例如将它与 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)
回答by Luca Davanzo
I get here looking for a solution to draw "arrows" in an existing view.
I'm pleased to share you some code that I hope usefull - Swift 2.3 compatible-
我来到这里寻找在现有视图中绘制“箭头”的解决方案。
我很高兴与您分享一些我希望有用的代码 - 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)
}
}
In this way you can call this for every kind of view:
通过这种方式，您可以为每种视图调用它：
let view = UIView(frame: frame)
view.addPikeOnView(side: .Top)
In a future I'll add offset for pike position.
将来，我将为派克位置添加偏移量。
- yes, names are definitely improvable!
- 是的，名字绝对可以改进！
SWIFT 3 Version
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))
}
}
回答by Dave DeLong
Perhaps a simpler question is "Is there code that does this for me already", to which the answer is "Yes".
也许一个更简单的问题是“是否有代码已经为我这样做了”，答案是“是”。
Behold MAAttachedWindow:
Granted, you may not want the whole "Attached window" behavior, but at least the drawing code is already there. (And Matt Gemmell's code is high quality stuff)
当然，您可能不想要整个“附加窗口”行为，但至少绘图代码已经存在。（和 Matt Gemmell 的代码是高质量的东西）
回答by Tim
There are two ways you might be able to accomplish this:
有两种方法可以实现这一点：
- Add a UIImageViewwith a triangle image in the right place. Make sure the rest of the image is transparent so as not to block your background.
- Override the
drawRect:method on your UIView to custom-draw the view. You can then add linear path components for your triangle, filling and bordering the path as necessary.
- 在正确的位置添加一个带有三角形图像的UIImageView。确保图像的其余部分是透明的，以免挡住背景。
- 覆盖
drawRect:UIView 上的方法以自定义绘制视图。然后，您可以为三角形添加线性路径组件，根据需要填充路径并为其设置边界。
To draw a simple triangle using drawRect:, you might do something like this. This snippet will draw a triangle pointing downwards at the bottom of your view.
要使用 绘制一个简单的三角形drawRect:，您可以执行以下操作。此代码段将在您的视图底部绘制一个向下的三角形。
// 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);
For more info, see the CGContext reference.
有关详细信息，请参阅CGContext 参考。
回答by kdgwill
For those using swift 2.0 based on the answer by Brad Larson
对于那些根据Brad Larson的回答使用 swift 2.0 的人
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)
}
回答by James Jordan Taylor
Swift 4 Update
斯威夫特 4 更新
Here's a Swift 4 version of AVT's original code.
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)
回答by ExitToShell
See the triangle on the pop up menu in the image below, thats drawn with Core Graphics funcs and is completely scalable.
请参阅下图中弹出菜单上的三角形，它是用 Core Graphics funcs 绘制的，并且是完全可扩展的。
Done like this to do an equilateral triangle (old-school function names, sorry):
这样做可以做一个等边三角形（老派函数名称，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);
}
}
Note that the triH(x) func is an optimized formula for calculating the height of an equitlateral triangle e.g. h = 1/2 * sqrt(3) * x . Since 1/2 * sqrt(3) never changes, I optimized it into that define.
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。
回答by pbush25
If anyone comes along looking for the Swift 3 answer, this does the trick! Thanks to those who contributed before I did, lovely piece of code!
如果有人来寻找 Swift 3 的答案，这就是诀窍！感谢那些在我之前做出贡献的人，一段可爱的代码！
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)
In my case triangleWidth = 10and triangleHeight = 5for a much smaller view than what's in OPs version.
在我的情况下，triangleWidth = 10并且triangleHeight = 5比 OP 版本中的视图小得多。
回答by Yetispapa
Here is the swift 3 solution of Brad Larson
这是Brad Larson的 swift 3 解决方案
override func draw(_ rect: CGRect) {
super.draw(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: CGContext = UIGraphicsGetCurrentContext()!
context.translateBy(x: 0.0, y: self.bounds.size.height)
context.scaleBy(x: 1.0, y: -1.0)
//
let currentFrame: CGRect = self.bounds
context.setLineJoin(CGLineJoin.round)
context.setLineWidth(strokeWidth)
context.setStrokeColor(UIColor.white.cgColor)
context.setFillColor(UIColor.black.cgColor)
// Draw and fill the bubble
context.beginPath()
context.move(to: CGPoint(x: borderRadius + strokeWidth + 0.5, y: strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5))
context.addLine(to: CGPoint(x: round(currentFrame.size.width / 2.0 - WIDTHOFPOPUPTRIANGLE / 2.0) + 0.5, y: HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5))
context.addLine(to: CGPoint(x: round(currentFrame.size.width / 2.0) + 0.5, y: strokeWidth + 0.5))
context.addLine(to: CGPoint(x: round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) + 0.5, y: HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5))
context.addArc(tangent1End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5), tangent2End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: currentFrame.size.height - strokeWidth - 0.5), radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: currentFrame.size.height - strokeWidth - 0.5) , tangent2End: CGPoint(x: round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) - strokeWidth + 0.5, y: currentFrame.size.height - strokeWidth - 0.5) , radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y: currentFrame.size.height - strokeWidth - 0.5), tangent2End: CGPoint(x: strokeWidth + 0.5, y: HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5), radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y :strokeWidth + HEIGHTOFPOPUPTRIANGLE + 0.5), tangent2End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5 ,y: HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5), radius: borderRadius - strokeWidth)
context.closePath()
context.drawPath(using: CGPathDrawingMode.fillStroke)
// Draw a clipping path for the fill
context.beginPath()
context.move(to: CGPoint(x: borderRadius + strokeWidth + 0.5, y: round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5))
context.addArc(tangent1End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5), tangent2End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: currentFrame.size.height - strokeWidth - 0.5), radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: currentFrame.size.height - strokeWidth - 0.5) , tangent2End: CGPoint(x: round(currentFrame.size.width / 2.0 + WIDTHOFPOPUPTRIANGLE / 2.0) - strokeWidth + 0.5, y: currentFrame.size.height - strokeWidth - 0.5), radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y: currentFrame.size.height - strokeWidth - 0.5), tangent2End: CGPoint(x: strokeWidth + 0.5, y: HEIGHTOFPOPUPTRIANGLE + strokeWidth + 0.5), radius: borderRadius - strokeWidth)
context.addArc(tangent1End: CGPoint(x: strokeWidth + 0.5, y: round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5), tangent2End: CGPoint(x: currentFrame.size.width - strokeWidth - 0.5, y: round((currentFrame.size.height + HEIGHTOFPOPUPTRIANGLE) * 0.50) + 0.5), radius: borderRadius - strokeWidth)
context.closePath()
context.clip()
}
