我遇到了这个问题。经过一些实验,结果证明获取设备来配置手电筒必须以与配置 AVCaptureSession 时获取设备完全相同的方式完成。例如。:
let captureSession = AVCaptureSession()
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: AVMediaType.video, position: .back)
guard let captureDevice = deviceDiscoverySession.devices.first else {
print("Couldn't get a camera")
return
}
do {
let input = try AVCaptureDeviceInput(device: captureDevice)
captureSession!.addInput(input)
} catch {
print(error)
return
}
使用该确切方法获取设备打开和关闭手电筒(手电筒)时。在这种情况下,这些行:
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: AVMediaType.video, position: .back)
guard let device = deviceDiscoverySession.devices.first
Example:
func toggleTorch() {
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: AVMediaType.video, position: .back)
guard let device = deviceDiscoverySession.devices.first
else {return}
if device.hasTorch {
do {
try device.lockForConfiguration()
let on = device.isTorchActive
if on != true && device.isTorchModeSupported(.on) {
try device.setTorchModeOn(level: 1.0)
} else if device.isTorchModeSupported(.off){
device.torchMode = .off
} else {
print("Torch mode is not supported")
}
device.unlockForConfiguration()
} catch {
print("Torch could not be used")
}
} else {
print("Torch is not available")
}
}
我意识到某些代码在toggleTorch 函数中可能是多余的,但我将其保留。希望这可以帮助。