ios - 带有单例的 AVCaptureSession。如何管理？

Question

伙计们，因为我有多个 View 和一些缩放按钮，我需要它们来更改预览相机输出，我认为使用 Singleton 进行 session 初始化是正确的，但我没有想法如何做到这一点，但找不到任何好的信息，有人可以帮助我吗？

Answer 1

更新

好的，所以，我设法以某种方式编写了它，我不知道是否可以，这是代码:

protocol Singleton: class {
static var sharedInstance: Self { get }
}


final class AVFSessionSingleton: Singleton {
static let sharedInstance = AVFSessionSingleton()
private init() {
    session = newVideoCaptureSession()!
}


var session: AVCaptureSession!
var imageOutput : AVCaptureStillImageOutput?

//FUNCTION

func newVideoCaptureSession () -> AVCaptureSession? {

    func initCaptureDevice() -> AVCaptureDevice? {
        var captureDevice: AVCaptureDevice?
        let devices: NSArray = AVCaptureDevice.devices() as NSArray

        for device: Any in devices {
            if (device as AnyObject).position == AVCaptureDevicePosition.back {
                captureDevice = device as? AVCaptureDevice
            }
        }
        print("device inited")
        return captureDevice
    }

    func initOutput() {
        self.imageOutput = AVCaptureStillImageOutput()
    }

    func initInputDevice(captureDevice : AVCaptureDevice) -> AVCaptureInput? {
        var deviceInput : AVCaptureInput?
        do {
            deviceInput = try AVCaptureDeviceInput(device: captureDevice)
        }
        catch _ {
            deviceInput = nil
        }
        return deviceInput
    }

    func initSession(deviceInput: AVCaptureInput) {
        self.session = AVCaptureSession()
        self.session?.sessionPreset = AVCaptureSessionPresetPhoto
        self.session?.addInput(deviceInput)
        self.session?.addOutput(self.imageOutput!)
    }

    return session
 }

}

所以现在我想以这种方式调用它，我可以管理预览的布局，请问有什么建议吗？......