出于隐私保护的考虑，相机模块会注册监听隐私的回调，在应用退后台或者设备熄屏状态下，如果应用未主动关闭相机，隐私会通知相机模块主动释放相机资源。在主动释放相机资源的过程中，也会关闭闪光灯等资源。
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {Release():1401} HStreamOperator::Release execute success
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {~AudioCapturerSession()-audio_capturer_session.cpp:96} ~AudioCapturerSession enter
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {Stop()-audio_capturer_session.cpp:199} Audio capture stop enter
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {Stop()-audio_capturer_session.cpp:207} Audio capture stop out
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {Release()-audio_capturer_session.cpp:215} current audioCapturer is nullptr
01-15 09:52:56.073 1706-1706 C02B01/camera_service/CAMERA camera_service I {Release()-audio_capturer_session.cpp:223} Audio capture released
01-15 09:52:56.076 48280-48280 C02B01/com.exa...camera/CAMERA com.examp...omcamera I {GetLensEquivalentFocalLength():400} CameraDevice::GetLensEquivalentFocalLength, lensEquivalentFocalLength size: 3, lensEquivalentFocalLength: [13,24,90]
01-15 09:52:56.076 48280-48280 C02B01/com.exa...camera/CAMERA com.examp...omcamera I {operator()():244} CameraId: device/0, CameraStatus: 2
01-15 09:52:56.084 1706-2569 C02B02/camera_...ce/CAMERA_DPS camera_service I {SetDefaultExecutionMode():211} DPS_PHOTO: SetDefaultExecutionMode to ive, ret: 0
01-15 09:52:56.084 1706-2569 C02B02/camera_...ce/CAMERA_DPS camera_service I {ReevaluateSchedulerInfo():308} DPS_EVENT: Video stop schedule, hdi: 0, mediaLibrary: 0, camera: 0, screen: 1, temperature: 0, photoRunning: 0
01-15 09:52:56.084 1706-2569 C02B02/camera_...ce/CAMERA_DPS camera_service I {OnSchedulerChanged():106} DPS_VIDEO: Video isNeedStop: 1, isCharging: 1
01-15 09:52:56.129 1706-1706 C02B01/camera_service/CAMERA camera_service I {OnFlashlightStatus_V1_2():681} CameraHostInfo::OnFlashlightStatus_V1_2, torch status is off
01-15 09:52:56.129 1706-1706 C02B01/camera_service/CAMERA camera_service I {OnFlashlightStatus_V1_2():681} CameraHostInfo::OnFlashlightStatus_V1_2, torch status is off
01-15 09:52:56.129 1706-1706 C02B01/camera_service/CAMERA camera_service I {OnTorchStatus():1235} HCameraService::OnTorchtStatus callbacks.size = 2, status = 0, pid = 1001
01-15 09:52:56.129 1706-1706 C02B01/camera_service/CAMERA camera_service I {OnTorchStatus():1235} HCameraService::OnTorchtStatus callbacks.size = 2, status = 0, pid = 1001
01-15 09:52:56.129 1706-1706 C02B01/camera_service/CAMERA camera_service I {OnTorchStatus():1235} HCameraService::OnTorchtStatus callbacks.size = 2, status = 0, pid = 1001
01-15 09:52:56.130 5747-5747 A01B06/com.ohos.sceneboard/KG com.ohos.sceneboard I QuickTool-FlashUtil: onTorchStatusChange torchLevel:0,isTorchAvailable:true
01-15 09:52:56.130 5747-5747 A01B06/com.ohos.sceneboard/KG com.ohos.sceneboard I QuickTool-FlashUtil: onTorchStatusChange torchLevel:0,isTorchAvailable:true
01-15 09:52:56.130 5747-5747 A01B06/com.ohos.sceneboard/KG com.ohos.sceneboard I QuickTool-FlashUtil: onTorchStatusChange torchLevel:0,isTorchAvailable:true
01-15 09:52:56.130 5747-5747 C02B01/com.oho...eboard/CAMERA com.ohos.sceneboard I {GetTorchMode():2051} GetTorchMode is called
01-15 09:52:56.130 5747-5747 C02B01/com.oho...eboard/CAMERA com.ohos.sceneboard I {GetTorchMode():2051} GetTorchMode is called
01-15 09:52:56.130 5747-5747 C02B01/com.oho...eboard/CAMERA com.ohos.sceneboard I {GetTorchMode():2051} GetTorchMode is called 从上述日志可以看出，是相机模块调用了Release()方法释放相机资源，在这一过程中也释放了闪光灯资源，并重置了闪光灯的状态。
01-15 09:52:55.412 1706-1706 C02B01/camera_service/CAMERA camera_service I {StateChangeNotify():88} CameraUseStateChangeCb::StateChangeNotify is called, isShowing: 0
01-15 09:52:55.412 1706-1706 C02B01/camera_service/CAMERA camera_service I {StateChangeNotify():100} CameraUseStateChangeCb::StateChangeNotify ClientName: com.example.customcamera, isSystemCamera: 0
01-15 09:52:55.509 48280-48280 C02B01/com.exa...camera/CAMERA com.examp...omcamera I {GetPreviewRotation():867} PreviewOutput GetPreviewRotation is called, imageRotation: 0
01-15 09:52:55.509 48280-48280 C02B01/com.exa...camera/CAMERA com.examp...omcamera I {GetPreviewRotation():891} PreviewOutput GetPreviewRotation :result 90, sensorOrientation:90
01-15 09:52:55.509 48280-48280 C02B01/com.exa...camera/CAMERA com.examp...omcamera I {GetPreviewRotation():916} PreviewOutputNapi GetPreviewRotation! 90
01-15 09:52:55.912 1706-1706 C02B01/camera_service/CAMERA camera_service I {StateChangeNotify():102} CameraUseStateChangeCb::StateChangeNotify wait timeout 从上述日志可以看出，相机框架通过调用StateChangeNotify()方法检查应用状态，发现“wait timeout”后主动释放相机资源。
应用退后台或者设备熄屏时，相机模块释放相机资源的动作是出于对用户隐私保护的考虑，无法绕过。
开发者可以通过ApplicationContext.on('applicationStateChange')接口注册应用进程状态变化的监听，在onApplicationBackground事件中主动停止录制并释放相机资源，在onApplicationForeground事件中再重新启动相机资源恢复录制。