Android相机在Lollipop上的IntentService中失败

Question

I'm trying to take a picture in the background from IntentService. On Android 4.4 all is ok, but on Android 5.1 I've got an error:

03-18 14:35:54.497 7659-8956/xyz.bringoff.proximityphoto.app E/InvisibleCameraService﹕ Can't use a camera: Fail to connect to camera service

My code looks like this:

private void handleActionShot() {

    mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    mProximity = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

    releaseCamera();

    mCamera = getCameraInstance();
}

public Camera getCameraInstance() {
    Camera c = null;

    int numCams = Camera.getNumberOfCameras();
    if (numCams > 0) {
        try {
            c = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
        } catch (RuntimeException e) {
            Log.e(TAG, "Can't use a camera: " + e.getMessage());
            releaseCamera();
            return null;
        }
    }
    if (c != null) {
        c.setParameters(getProperParametersForCurrentDevice(c));
        c.lock();
    }

    return c;
}

I did not find a documented difference between camera requests on this two android versions.

Answer 1

I have found a problem. Receiver caught intent with STATE_OFFHOOK twice and respectively started IntentService twice. I get a camera instance on the first start, so the second time I caught onHandleIntent() camera was already locked. So, I added a check in onHandleIntent() method

if (ACTION_SHOT.equals(action) && !mAlreadyRunning) {
            mAlreadyRunning = true;
            handleActionShot();
        }

and now it works.