以按钮为例子，实现虚线按钮：
CAShapeLayer *border = [CAShapeLayer layer];
//虚线的颜色
border.strokeColor = [UIColor colorWithHexString:@"#333333"].CGColor;
//填充的颜色
border.fillColor = [UIColor clearColor].CGColor;
//设置路径
border.path = [UIBezierPath bezierPathWithRect:self.clickUploadBtn.bounds].CGPath;
border.frame = self.clickUploadBtn.bounds;
//虚线的宽度
border.lineWidth = 1.f;
//设置线条的样式
// border.lineCap = @"square";
//虚线的间隔
border.lineDashPattern = @[@4, @2];
[self.clickUploadBtn.layer addSublayer:border];
image.png
到这里基本已经OK了，但是突然发现我要的是有圆角的按钮，那就去添加圆角
btn.layer.cornerRadius = 15;
btn.clipsToBounds = YES;
然而效果是这样子的，四个角变的很奇怪
image.png
最后找资料终于得到实现效果 需要把bezierPathWithRect 替换成 bezierPathWithRoundedRect 就可以了
CAShapeLayer *border = [CAShapeLayer layer];
//虚线的颜色
border.strokeColor = [UIColor colorWithHexString:@"#333333"].CGColor;
//填充的颜色
border.fillColor = [UIColor clearColor].CGColor;
//设置路径
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.clickUploadBtn.bounds cornerRadius:15];
border.path = path.CGPath;
border.frame = self.clickUploadBtn.bounds;
//虚线的宽度
border.lineWidth = 1.f;
//设置线条的样式
// border.lineCap = @"square";
//虚线的间隔
border.lineDashPattern = @[@4, @2];
[self.clickUploadBtn.layer addSublayer:border];
最终效果：
image.png
