调用相机camera.open失败Fail to connect to camera service

Question

权限有了

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <!-- 调用硬件相机权限 -->
    <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" />

         @Override
    public void surfaceCreated(SurfaceHolder holder) {
        if (!hasSurface) {
            hasSurface = true;
            initCamera(holder);
        }

    }

         @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        hasSurface = false;
        if (camera != null) {
            if (CameraManager.get().isPreviewing()) {
                if (!CameraManager.get().isUseOneShotPreviewCallback()) {
                    camera.setPreviewCallback(null);
                }
                camera.stopPreview();
                camera.release();
                camera = null;
                CameraManager.get().getPreviewCallback().setHandler(null, 0);
                CameraManager.get().getAutoFocusCallback().setHandler(null, 0);
                CameraManager.get().setPreviewing(false);
            }
        }
    }

         private void initCamera(SurfaceHolder surfaceHolder) {
        try {
            //6.0+调用相机权限
            if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions((Activity) getContext(),
                        new String[]{Manifest.permission.CAMERA},
                        TAKE_PHOTO_REQUEST_CODE);
            }else {
                camera = Camera.open();
                parameter = camera.getParameters();
                CameraManager.get().openDriver(surfaceHolder);
                camera = CameraManager.get().getCamera();
                camera.startPreview();
            }

        } catch (IOException | RuntimeException e) {
            L.e(e.getMessage());
            return;
        }
        if (handler == null) {
            handler = new CaptureActivityHandler(this, decodeFormats, characterSet, viewfinderView);
        }
    }

请问少了什么，为什么会失败？
在6.0上测试没问题，换了红米2A 4.4的系统就不行了。
求解
谢谢~

Answer 1

已解决，参考 http://blog.csdn.net/jdsjlzx/article/details/43098179

在
@Override
public void onPause() {
super.onPause();
if (handler != null) {
handler.quitSynchronously();
handler = null;
}
// 关闭摄像头
CameraManager.get().closeDriver();
//添加以下代码，问题解决。
** if (!hasSurface) {
SurfaceView surfaceView = (SurfaceView) view.findViewById(R.id.preview_view);
SurfaceHolder surfaceHolder = surfaceView.getHolder();
surfaceHolder.removeCallback(this);
}**
}