ios - AVCaptureDevice.devices调整为AVCaptureDeviceDiscoverySession

由于AVCaptureDevice.devices在iOS 10中已贬值，因此我尝试将此示例代码调整为AVCaptureDeviceDiscoverySession。

var error: NSError?
var captureSession: AVCaptureSession?
var backVideoDevice: AVCaptureDevice?
//let videoDevices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo) // .devices DEPRECIATED

//iOS 10
let videoDevices = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back)

// Get back video device
if let videoDevices = videoDevices
{
    for captureDevice in videoDevices
    {
        if (captureDevice as AnyObject).position == AVCaptureDevicePosition.back
        {
            backVideoDevice = captureDevice as? AVCaptureDevice
            break
        }
    }
}

在这里我卡住了，在这条线上出现了一个错误

for captureDevice in videoDevices

此时videoDevices显示：键入“AVCaptureDeviceDiscoverySession”不符合协议“Sequence”。
我错过了什么或监督了什么？谢谢。

最佳答案

该函数返回一个AVCaptureDeviceDiscoverySession类型的对象，您必须访问该对象的devices属性才能获取所需的数组：

    let session = AVCaptureDeviceDiscoverySession.init(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back)
    if let device = session?.devices[0] {
        backVideoDevice = device
    }

注意，您不再需要在所有设备上循环，因为AVCaptureDeviceDiscoverySession只返回一开始position为.back的设备。因为只有一个，你可以在devices[0]找到它。

关于ios - AVCaptureDevice.devices调整为AVCaptureDeviceDiscoverySession，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41904375/