Camera flash is not working in android

Question

I am trying to make a simple app that will on button click turn the camera flash on and on another click it will turn off so that we can use it as an torch light. But the flash is not turing on. below is my flashfragment

public class FlashFragment extends Fragment {

private boolean isLighOn = false;
private Camera camera;
private Button button;

public FlashFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_flash, container, false);
    button = (Button) rootView.findViewById(R.id.buttonFlashlight);

    Context context = getActivity();
    PackageManager pm = context.getPackageManager();

    // if device support camera?
    if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
        Log.e("err", "Device has no camera!");

    }
    try{
        camera = Camera.open();
        final Camera.Parameters p = camera.getParameters();

        button.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {

                if (isLighOn) {

                    Log.i("info", "torch is turn off!");

                    p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
                    camera.stopPreview();
                    isLighOn = false;

                } else {

                    Log.i("info", "torch is turn on!");

                    p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
                    camera.startPreview();
                    isLighOn = true;

                }

            }
        });
    }catch(Exception e){
        e.printStackTrace();
    }

    // Inflate the layout for this fragment
    return rootView;
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
}

@Override
public void onDetach() {
    super.onDetach();
}
}

Answer 1

You just missed the line to set parameter to the camera

camera.setParameters(p);

So, your code for onClickListener should look something like following

 button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {

            if (isLighOn) {

                Log.i("info", "torch is turn off!");

                p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
                camera.setParameters(p);
                camera.stopPreview();
                isLighOn = false;

            } else {

                Log.i("info", "torch is turn on!");

                p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
                camera.setParameters(p);
                camera.startPreview();
                isLighOn = true;

            }

        }
    });

This should solve your problem. it always works in my case.

Answer 2

A few years back I was experiencing heaps of problems with the camera and the flashlight.

Some devices are stranger than others.

Make sure to check, if a flash exists

hasFlash = context.getPackageManager().hasSystemFeature(
            PackageManager.FEATURE_CAMERA_FLASH);

Then I found out, that some cameras need a surfaceTexture to enable flash (even if it is just a dummy one):

SurfaceTexture dummy = new SurfaceTexture(0);
mCamera.setPreviewTexture(dummy);

For enabling I used this method:

public void enable() {
    if (!isReady) {
        return;
    }
    try {
        mCamera.reconnect();
        mParameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
        mCamera.setParameters(mParameters);
        mCamera.startPreview();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

I am not sure anymore, if the reconnect() was needed. But I am pretty sure, startPreview() is needed.

And finally I had some devices that accepted

Parameters.FLASH_MODE_ON

instead of FLASH_MODE_TORCH. Strange, because Docs say something different about that mode, but that is what I experienced in the past (maybe this info is even outdated).

Don't forget to release the camera.

Hope that helps to minimize problems with the flash light.