闪光灯

 func toggleFlash()
 {
 let captureDevice1 = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
 if(captureDevice1.hasFlash)
 {
 do {
 try captureDevice1.lockForConfiguration()
 } catch
 {
 print("lockForConfiguration error")
 }
 if( captureDevice1.torchMode == AVCaptureTorchMode.On)
 {
 captureDevice1.torchMode = AVCaptureTorchMode.Off
 }else
 {
 do {
 try captureDevice1.setTorchModeOnWithLevel(1.0)
 }catch
 {
 print("setTorchModeOnWithLevel error")
 }
 }
 captureDevice1.unlockForConfiguration()
 }
 }