ios – 在自定义相机层的AVFoundation中自动对焦和自动曝光

为AVFoundation定制图层相机创建精确的自动对焦和曝光的最佳方法是什么？例如,目前我的相机预览图层是方形的,我希望将相机焦点和曝光指定到该帧边界.如果可能的话,我需要在 Swift 2中使用它,如果没有,请写下你的答案我可以自己转换它.

当前自动聚焦和曝光：但是正如您所看到的,这将在聚焦时评估整个视图.

override func touchesBegan(touches: Set<UITouch>,withEvent event: UIEvent?) {
    //Get Touch Point
    let Point = touches.first!.locationInView(self.capture)
    //Assign Auto Focus and Auto Exposour
    if let device = currentCameraInput {
        do {
            try! device.lockForConfiguration()
            if device.focusPointOfInterestSupported{
                //Add Focus on Point
                device.focusPointOfInterest = Point
                device.focusMode = AVCaptureFocusMode.AutoFocus
            }

            if device.exposurePointOfInterestSupported{
                //Add Exposure on Point
                device.exposurePointOfInterest = Point
                device.exposureMode = AVCaptureExposureMode.AutoExpose
            }
            device.unlockForConfiguration()
        }
    }
}

相机层：1：1比例的任何内容都应被视为焦点和曝光点,此范围之外的任何内容甚至不会被视为相机焦点的触摸事件.

public func captureDevicePointOfInterestForPoint(pointInLayer: CGPoint) -> CGPoint