ios - 可视化点击 View ，显示点击指示器

Question

我正在尝试添加点击以聚焦到我的自定义相机 View 上，我设法做到了，但现在我需要显示一些东西，以便用户可以知道他实际上正在做某事......显示一个 UI，如 Apple 的黄色正方形，或 SnapChat 的白色圆圈。自定义指标...

这是我的代码:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        let screenSize = view.bounds.size
        if let touchPoint = touches.first {
            let x = touchPoint.location(in: view).y / screenSize.height
            let y = 1.0 - touchPoint.location(in: view).x / screenSize.width
            let focusPoint = CGPoint(x: x, y: y)
            
            if let device = captureDevice {
                do {
                    try device.lockForConfiguration()
                    
                    device.focusPointOfInterest = focusPoint
                    //device.focusMode = .continuousAutoFocus
                    device.focusMode = .autoFocus
                    //device.focusMode = .locked
                    device.exposurePointOfInterest = focusPoint
                    device.exposureMode = AVCaptureExposureMode.continuousAutoExposure
                    device.unlockForConfiguration()
                }
                catch {
                    // just ignore
                }
            }
        }
    }

现在如何在该点击上添加自定义指示器以聚焦？谢谢

Answer 1

在屏幕的其余部分之上添加一个叠加 View 。然后您可以在其 draw() 函数中绘制您的指标。每当您需要覆盖显示更新时调用其 setNeedsDisplay() 函数。在下面的示例中，我在设置函数中包含了 touchPoint。确保在此 View 上禁用用户交互，否则您的触摸将无法通过底层用户界面。

class OverlayView : UIView {

    override func draw(_ rect: CGRect) {
        // draw your touch indicator here
        if let pt = _touchPoint {
            let color:UIColor = UIColor.gray
            let rect = CGRect(x:pt.x - 30, y:pt.y - 30, width:60, height:60)
            let bpath:UIBezierPath = UIBezierPath(rect: rect)

            color.set()
            bpath.stroke()
        }
    }

    private var _touchPoint : CGPoint?
    var touchPoint : CGPoint? {
        set(value) {
            _touchPoint = value
            setNeedsDisplay()
        }
        get {
            return _touchPoint
        }
    }

}