Flashlight Camera2 API

Question

Can I use camera preview and flashlight at the same time in Android Camera2 API?

When I try use CameraManager.setTorchMode(String cameraId, boolean enabled)

Answer 1

No, they're mutually exclusive.

The camera device needs exclusive control of the flash while the camera is open, to ensure it can fire it as needed for pictures and so on.

If you want to turn on the torch while the camera is open, then use the camera API's flash mode setting. For the new camera2 API, that's setting the auto-exposure mode to just ON (CONTROL_AE_MODE_ON) and the flash mode to TORCH (FLASH_MODE_TORCH). And for the old camera API, that's Parameters.setFlashMode.