Swift 3 'CGContextAddArc' 不可用 : Use addArc(center:radius:startAngle:endAngle:clockwise:)

Question

我这里有这行代码:

CGContextAddArc(context, (round(frame.size.width))/(2 * (appDelegate.webview?.scrollView.zoomScale)!), round(frame.size.height)/(2 * (appDelegate.webview?.scrollView.zoomScale)!), (round(frame.size.width) - 10)/(2 * (appDelegate.webview?.scrollView.zoomScale)!), 0.0, CGFloat(M_PI * 2.0), 1)

但是你现在得到这个错误:

'CGContextAddArc' is unavailable: Use addArc(center:radius:startAngle:endAngle:clockwise:)

所以我尝试使用 addArc 但是当我开始输入它时，该方法没有出现，如何调用 addArc？

这是我的完整代码:

func drawCircle()
    {
        // Get the Graphics Context
        let context = UIGraphicsGetCurrentContext();

        // Set the circle outerline-width
        context?.setLineWidth(5.0);

        // Set the circle outerline-colour
        UIColor.red.set()

        // Create Circle
        CGContextAddArc(context, (round(frame.size.width))/(2 * (appDelegate.webview?.scrollView.zoomScale)!), round(frame.size.height)/(2 * (appDelegate.webview?.scrollView.zoomScale)!), (round(frame.size.width) - 10)/(2 * (appDelegate.webview?.scrollView.zoomScale)!), 0.0, CGFloat(M_PI * 2.0), 1)

        // Draw
        context?.strokePath();
    }

Answer 1

let center = CGPoint(x:(round(frame.size.width))/(2 * (appDelegate.webview?.scrollView.zoomScale)!), y:round(frame.size.height)/(2 * (appDelegate.webview?.scrollView.zoomScale)!))
let radius = (round(frame.size.width) - 10)/(2 * (appDelegate.webview?.scrollView.zoomScale)!)

context.addArc(center: center, radius: radius, startAngle: 0, endAngle: CGFloat(M_PI * 2.0), clockwise: true)