我试图了解如何使用Swift创建三角形。我发现这个代码创建了一个三角形。
class TriangleLayer: CAShapeLayer {
let innerPadding: CGFloat = 30.0
override init() {
super.init()
fillColor = Colors.red.CGColor
strokeColor = Colors.red.CGColor
lineWidth = 7.0
lineCap = kCALineCapRound
lineJoin = kCALineJoinRound
path = trianglePathSmall.CGPath
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
var trianglePathSmall: UIBezierPath {
let trianglePath = UIBezierPath()
trianglePath.moveToPoint(CGPoint(x: 5.0 + innerPadding, y: 95.0)) // #1
trianglePath.addLineToPoint(CGPoint(x: 50.0, y: 12.5 + innerPadding)) // #2
trianglePath.addLineToPoint(CGPoint(x: 95.0 - innerPadding, y: 95.0)) // #3
trianglePath.closePath()
return trianglePath
}
我尝试调整并玩弄它以了解它是如何工作的;然而,在这一点上,我意识到我迷失了很多逻辑。我将上面三角形的CGPoints放在我脑海中的x-y轴上,看起来像是:
#1 x:35, y:95 #3 x:65, y:95
#2 x:50, y: 42.5
但如果我将点放在x-y轴上,则三角形会颠倒创建。
我想要达到的是轴所说的,我想实现......
. . .
<like this. not this>
. . .
答案 0 :(得分:9)
你的脑斧头倒置了。坐标系从0,0开始,在X中向右延伸,在Y中向下延伸。
所以你的观点确实如此:
string sPlaintext;
cout << "\nInserisci testo : ";
getline(cin, sPlaintext);
uchar* szPlaintext = (uchar*) sPlaintext.c_str(); //dato da criptare
获得您想要的三角形,您可以使用以下内容:
#2 x:50, y: 42.5
#1 x:35, y:95 #3 x:65, y:95
答案 1 :(得分:1)
swift5中的代码
//TriangleView
extension UIView {
func setRightTriangle(targetView:UIView?){
let heightWidth = targetView!.frame.size.width //you can use triangleView.frame.size.height
let path = CGMutablePath()
path.move(to: CGPoint(x: heightWidth/2, y: 0))
path.addLine(to: CGPoint(x:heightWidth, y: heightWidth/2))
path.addLine(to: CGPoint(x:heightWidth/2, y:heightWidth))
path.addLine(to: CGPoint(x:heightWidth/2, y:0))
let shape = CAShapeLayer()
shape.path = path
shape.fillColor = UIColor.blue.cgColor
targetView!.layer.insertSublayer(shape, at: 0)
}
func setLeftTriangle(targetView:UIView?){
let heightWidth = targetView!.frame.size.width
let path = CGMutablePath()
path.move(to: CGPoint(x: heightWidth/2, y: 0))
path.addLine(to: CGPoint(x:0, y: heightWidth/2))
path.addLine(to: CGPoint(x:heightWidth/2, y:heightWidth))
path.addLine(to: CGPoint(x:heightWidth/2, y:0))
let shape = CAShapeLayer()
shape.path = path
shape.fillColor = UIColor.blue.cgColor
targetView!.layer.insertSublayer(shape, at: 0)
}
func setUpTriangle(targetView:UIView?){
let heightWidth = targetView!.frame.size.width
let path = CGMutablePath()
path.move(to: CGPoint(x: 0, y: heightWidth))
path.addLine(to: CGPoint(x:heightWidth/2, y: heightWidth/2))
path.addLine(to: CGPoint(x:heightWidth, y:heightWidth))
path.addLine(to: CGPoint(x:0, y:heightWidth))
let shape = CAShapeLayer()
shape.path = path
shape.fillColor = UIColor.blue.cgColor
targetView!.layer.insertSublayer(shape, at: 0)
}
func setDownTriangle(targetView:UIView?){
let heightWidth = targetView!.frame.size.width
let path = CGMutablePath()
path.move(to: CGPoint(x: 0, y: 0))
path.addLine(to: CGPoint(x:heightWidth/2, y: heightWidth/2))
path.addLine(to: CGPoint(x:heightWidth, y:0))
path.addLine(to: CGPoint(x:0, y:0))
let shape = CAShapeLayer()
shape.path = path
shape.fillColor = UIColor.blue.cgColor
targetView!.layer.insertSublayer(shape, at: 0)
}
}
答案 2 :(得分:-1)
快速4。*
使用自动版式的最简单方法:
UIView
中拖动UIViewController
,将其放置并根据需要设置大小(这就是三角形所在的位置)。将视图背景设置为透明。TriangleView
)。这将是该类的内容: class TriangleView: UIView {
// predefined variables that can be changed
var startPoint: CGPoint = CGPoint(x: 0.0, y: 0.5)
var endPoint: CGPoint = CGPoint(x: 1.0, y: 0.5)
var firstGradientColor: UIColor = UIColor.white
var secondGradientColor: UIColor = UIColor.blue
let gradient: CAGradientLayer = CAGradientLayer()
override func draw(_ rect: CGRect) {
let height = self.layer.frame.size.height
let width = self.layer.frame.size.width
// draw the triangle
let path = UIBezierPath()
path.move(to: CGPoint(x: width / 2, y: 0))
path.addLine(to: CGPoint(x: width, y: height))
path.addLine(to: CGPoint(x: 0, y: height))
path.close()
// draw the triangle 'upside down'
// let path = UIBezierPath()
// path.move(to: CGPoint(x: 0, y: 0))
// path.addLine(to: CGPoint(x: width, y: 0))
// path.addLine(to: CGPoint(x: width / 2, y: height))
// path.close()
// add path to layer
let shapeLayer = CAShapeLayer()
shapeLayer.path = path.cgPath
shapeLayer.lineWidth = 1.0
// Add the gradient for the view background if needed
gradient.colors = [firstGradientColor.cgColor, secondGradiendColor.cgColor]
gradient.startPoint = startPoint
gradient.endPoint = endPoint
gradient.frame = self.bounds
gradient.mask = shapeLayer
self.layer.addSublayer(gradient)
}
}
转到您的Storyboard
,选择UIView
,然后在Identity Inspector
中输入类名TriangleView
享受你的三角形! :)