需要 UIBezierPath 的提示。像 Instagram 一样的三角形注册视图

Question

我正在尝试创建一个贝塞尔曲线路径，就像下图中的 instagram 三角形一样，但是我一定是做错了什么。贝塞尔路径不显示！

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.

}

-(void)viewDidLayoutSubviews{
[super viewDidLayoutSubviews];

[self drawTriangle];

}

- (IBAction)closeButton:(UIButton *)sender {
[self dismissViewControllerAnimated:YES completion:nil];
}

- (void)drawTriangle{

UIBezierPath* trianglePath = [UIBezierPath bezierPath];
[trianglePath moveToPoint:CGPointMake(self.signUpButton.center.x, self.signUpButton.frame.origin.y + 30)];
[trianglePath addLineToPoint:CGPointMake(self.signUpButton.center.x - 10, self.imageView.frame.size.height)];
[trianglePath addLineToPoint:CGPointMake(self.signUpButton.center.x + 10, self.imageView.frame.size.height)];

UIColor *fillColor = [UIColor whiteColor];
[fillColor setFill];
UIColor *strokeColor = [UIColor whiteColor];
[strokeColor setStroke];

 [trianglePath fill];
[trianglePath stroke];

[trianglePath closePath];
}

Answer 1

Xcode 10 • Swift 4.2

func drawTriangle(size: CGFloat, x: CGFloat, y: CGFloat, up:Bool) {

    let triangleLayer = CAShapeLayer()
    let trianglePath = UIBezierPath()
    trianglePath.move(to: .zero)
    trianglePath.addLine(to: CGPoint(x: -size, y: up ? size : -size))
    trianglePath.addLine(to: CGPoint(x: size, y: up ? size : -size))
    trianglePath.close()
    triangleLayer.path = trianglePath.cgPath
    triangleLayer.fillColor = UIColor.white.cgColor
    triangleLayer.anchorPoint = .zero
    triangleLayer.position = CGPoint(x: x, y: y)
    triangleLayer.name = "triangle"
    view.layer.addSublayer(triangleLayer)
}

drawTriangle(size: 12, x: view.frame.midX/2, y: view.frame.midY, up: true)
drawTriangle(size: 12, x: view.frame.midX, y: view.frame.midY, up: false)

Answer 2

这是一些示例代码，我在我的项目中为 UIButton 绘制了一个三角形并且运行良好。

UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setBackgroundColor:[UIColor redColor]];
btn.frame = CGRectMake(100, 100, 80, 53);
[self.view addSubview:btn];

UIBezierPath* bezierPath = UIBezierPath.bezierPath;
[bezierPath moveToPoint:CGPointMake(40, 43)];
[bezierPath addLineToPoint:CGPointMake(25, 53)];
[bezierPath addLineToPoint:CGPointMake(55, 53)];
[bezierPath closePath];

CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = btn.bounds;
shapeLayer.path = bezierPath.CGPath;
shapeLayer.fillColor = [UIColor whiteColor].CGColor;

[btn.layer addSublayer:shapeLayer];

如果您想在单击下一个按钮时删除上一个按钮的三角形，请使用以下代码片段：

NSArray *arr = btn.layer.sublayers;

for (id class in arr) {

    if ([class isKindOfClass:[CAShapeLayer class]] ) {
        [class removeFromSuperlayer];
    }
}

需要 UIBezierPath 的提示。像 Instagram 一样的三角形注册视图

Need a tip with UIBezierPath. Triangle Shape like Instagram Sign Up View

ios

objective-c

uibezierpath

cashapelayer