UIBezierPath的起始和结束角度？

本文介绍了UIBezierPath的起始和结束角度？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我使用 UIBezierPath 和 CAShapeLayer 在iOS中编码如下半圈。 clockWiseLayer = [[CAShapeLayer alloc] init]; CGFloat startAngle = -M_PI_2; CGFloat endAngle = M_PI + M_PI_2; CGFloat width = CGRectGetWidth（imageView.frame）/2.0f + 30; CGFloat height = CGRectGetHeight（imageView.frame）/2.0f +50; CGPoint centerPoint = CGPointMake（宽度，高度）; float radius = CGRectGetWidth（imageView.frame）/ 2 + 10; clockWiseLayer.path = [UIBezierPath bezierPathWithArcCenter：centerPoint radius：radius startAngle：startAngle endAngle：endAngle 顺时针：是] .CGPath; clockWiseLayer.fillColor = [UIColor clearColor] .CGColor; clockWiseLayer.strokeColor = [UIColor blueColor] .CGColor; clockWiseLayer.borderColor = [UIColor greenColor] .CGColor; clockWiseLayer.backgroundColor = [UIColor redColor] .CGColor; clockWiseLayer.strokeStart = 0.0f; clockWiseLayer.strokeEnd = 0.5f; clockWiseLayer.lineWidth = 2.0f; clockWiseLayer.borderWidth = 5.0f; clockWiseLayer.shouldRasterize = NO; [self.layer addSublayer：clockWiseLayer]; 结果如下。 我希望在World Globe的另一侧有一个蓝色半圈。 它是半圈，但我想要它在另一边，也是CounterClockWise。 我无法设置开始和结束角度，而顺时针：否。 谢谢。解决方案检查文档坐标： Y轴是与数学中的标准坐标系相比发生逆转。 您应该从1/2 * PI（底部锚点）绘制到3/2 * PI（顶部锚点）然后将strokeStart设置为0.0f并将strokeEnd设置为1.0f（因此它填充整个路径使用iOS常量的工作代码： CGFloat startAngle = M_PI_2; CGFloat endAngle = startAngle + M_PI; CGFloat width = CGRectGetWidth（imageView.frame）/2.0f; CGFloat height = CGRectGetHeight（imageView.frame）/2.0f; CGPoint centerPoint = CGPointMake（宽度，高度）; float radius = CGRectGetWidth（imageView.frame）/ 2 + 10; CAShapeLayer * clockWiseLayer = [[CAShapeLayer alloc] init]; clockWiseLayer.path = [UIBezierPath bezierPathWithArcCenter：centerPoint radius：radius startAngle：startAngle endAngle：endAngle 顺时针：是] .CGPath; clockWiseLayer.fillColor = [UIColor clearColor] .CGColor; clockWiseLayer.strokeColor = [UIColor blueColor] .CGColor; clockWiseLayer.borderColor = [UIColor greenColor] .CGColor; clockWiseLayer.backgroundColor = [UIColor redColor] .CGColor; clockWiseLayer.strokeStart = 0.0f; clockWiseLayer.strokeEnd = 1.0f; clockWiseLayer.lineWidth = 2.0f; clockWiseLayer.borderWidth = 5.0f; [self.layer addSublayer：clockWiseLayer]; I have coded as below for half circle in iOS using UIBezierPath and CAShapeLayer. clockWiseLayer = [[CAShapeLayer alloc] init];CGFloat startAngle = -M_PI_2;CGFloat endAngle = M_PI + M_PI_2;CGFloat width = CGRectGetWidth(imageView.frame)/2.0f + 30;CGFloat height = CGRectGetHeight(imageView.frame)/2.0f +50;CGPoint centerPoint = CGPointMake(width, height);float radius = CGRectGetWidth(imageView.frame)/2+10;clockWiseLayer.path = [UIBezierPath bezierPathWithArcCenter:centerPoint radius:radius startAngle:startAngle endAngle:endAngle clockwise:YES].CGPath;clockWiseLayer.fillColor = [UIColor clearColor].CGColor;clockWiseLayer.strokeColor = [UIColor blueColor].CGColor;clockWiseLayer.borderColor = [UIColor greenColor].CGColor;clockWiseLayer.backgroundColor = [UIColor redColor].CGColor;clockWiseLayer.strokeStart = 0.0f;clockWiseLayer.strokeEnd = 0.5f;clockWiseLayer.lineWidth = 2.0f;clockWiseLayer.borderWidth = 5.0f;clockWiseLayer.shouldRasterize = NO;[self.layer addSublayer:clockWiseLayer];This results as below.I want this blue half circle on the opposite side of the World Globe.It is half Circle, but I want it on the other side, also CounterClockWise.I am unable to set start and end angle for that, while clockwise:NO.Thanks. 解决方案 Check documentation for coordinates:http://i.stack.imgur.com/1yJo6.pngY-Axis is reversed compared to standard coordinate system in mathematics.You should draw from 1/2*PI (bottom anchor) to 3/2*PI (top anchor) and then you set strokeStart to 0.0f and strokeEnd to 1.0f (so it fills whole path).Working code using iOS constants:CGFloat startAngle = M_PI_2;CGFloat endAngle = startAngle + M_PI;CGFloat width = CGRectGetWidth(imageView.frame)/2.0f;CGFloat height = CGRectGetHeight(imageView.frame)/2.0f;CGPoint centerPoint = CGPointMake(width, height);float radius = CGRectGetWidth(imageView.frame)/2+10;CAShapeLayer* clockWiseLayer = [[CAShapeLayer alloc] init];clockWiseLayer.path = [UIBezierPath bezierPathWithArcCenter:centerPoint radius:radius startAngle:startAngle endAngle:endAngle clockwise:YES].CGPath;clockWiseLayer.fillColor = [UIColor clearColor].CGColor;clockWiseLayer.strokeColor = [UIColor blueColor].CGColor;clockWiseLayer.borderColor = [UIColor greenColor].CGColor;clockWiseLayer.backgroundColor = [UIColor redColor].CGColor;clockWiseLayer.strokeStart = 0.0f;clockWiseLayer.strokeEnd = 1.0f;clockWiseLayer.lineWidth = 2.0f;clockWiseLayer.borderWidth = 5.0f;[self.layer addSublayer:clockWiseLayer]; 这篇关于UIBezierPath的起始和结束角度？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！