“获取异常照相机”；0“；被政策禁用'；当试图在后台打开相机时，Android 10

该代码在低于10的Android版本中运行良好

我有一个广播接收器计划在AlarmManager指定的时间运行。当它被触发时，它会打开一个后台服务，使用摄像头拍照

如果屏幕上显示MainActivity，则工作正常。如果单击“上一步”或activty未运行，则会出现此异常

W/CameraBase: An error occurred while connecting to camera 0: Status(-8, EX_SERVICE_SPECIFIC): '6: connectHelper:1735: Camera "0" disabled by policy'

在这条线上

  c = Camera.open();

还试图显示通知并使服务作为前台服务从广播接收器启动，我得到相同的异常

W/CameraBase: An error occurred while connecting to camera 0: Status(-8, EX_SERVICE_SPECIFIC): '6: connectHelper:1735: Camera "0" disabled by policy'

代码片段：

 @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // sv = new SurfaceView(getApplicationContext());
        cameraIntent = intent;

        pref = getApplicationContext().getSharedPreferences("MyPref", 0);
        editor = pref.edit();

        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);
        params.gravity = Gravity.TOP | Gravity.LEFT;
        params.width = 1;
        params.height = 1;
        params.x = 0;
        params.y = 0;
        sv = new SurfaceView(getApplicationContext());
        windowManager.addView(sv, params);
        sHolder = sv.getHolder();
        sHolder.addCallback(this);

        // tells Android that this surface will have its data constantly
        // replaced
        if (Build.VERSION.SDK_INT < 11)
            sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        return START_STICKY;
    }


public static Camera getCameraInstance() {
        Camera c = null;
        try {
            c = Camera.open(); // attempt to get a Camera instance
        } catch (Exception e) {
            // Camera is not available (in use or does not exist)
            e.printStackTrace();
        }
        return c; // returns null if camera is unavailable
    }


        @Override
        public void onPictureTaken(byte[] data, Camera camera) {

            try {
                saveImage(data, System.currentTimeMillis() + "");
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (mCamera != null) {
                // decode the data obtained by the camera into a Bitmap
                if (mCamera != null) {
                    mCamera.stopPreview();
                    mCamera.release();
                    mCamera = null;
                }
                /*
                 * Toast.makeText(getApplicationContext(),
                 * "Your Picture has been taken !", Toast.LENGTH_LONG).show();
                 */
                Log.d("Camera", "Image Taken !");

                mCamera = null;
                showToast("Your Picture has been taken !", Toast.LENGTH_SHORT);
                stopSelf();
            }
        }

---

如果您正在Android 11上进行测试，请参阅。

public class MyReceiver extends BroadcastReceiver {
    PowerManager pawerManager;
    public static PowerManager.WakeLock wakeLock=null;
    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    public void onReceive(Context context, Intent intent) {
        pawerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        wakeLock = pawerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                "CameraApp:CameraReceiver");
        wakeLock.acquire();
        Log.d("Receiver: ","CameraApp:CameraReceiver called");
        Intent serviceIntent=new Intent(context,CameraService.class);



        ContextCompat.startForegroundService(context, serviceIntent);
    }
}