如何只用它的笔画画圆圈

Question

我只是想用笔划绘制圆圈，下面的代码画得很好，但它填满了圆圈。

我不希望它被填满。请帮帮我

    self.circleView = [[UIView alloc] initWithFrame:CGRectMake(10,20,20,20)];
    circleView.alpha = 0.5;
    self.circleView.layer.cornerRadius = 50;
    self.circleView.backgroundColor = [UIColor whiteColor];

Answer 1

更改

self.circleView.backgroundColor = [UIColor whiteColor];

到

self.circleView.backgroundColor = [UIColor clearColor];

并为边框（Stroke）添加

self.circleView.layer.borderColor = [[UIColor redColor] CGColor];
self.circleView.layer.borderWidth = 1;