我想使用setTheme到活动对话框而不将黑屏显示到第一个Activity

Question

我制作应用程序来阅读条形码。我在它上面使用了surfaceview和camerasource。我想在活动对话框中显示结果，并在返回时重新启动surfaceview和相机源，所以我在onCreate方法的第一行添加setTheme，如下所示

setTheme(android.R.style.Theme_DeviceDefault_Light_Dialog);

问题是第一个活动在黑屏中显示如何显示第一个活动，我想在对话框下显示第一个活动的其他部分

这是第一个活动

的创建方法代码的全部内容

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        surfaceView = (SurfaceView) findViewById(R.id.cameraPreview);
        txtShow = (TextView) findViewById(R.id.txtShow);

        startBarcode();

    }

    public void startBarcode() {
        barcodeDetector = new BarcodeDetector.Builder(this)
                .setBarcodeFormats(Barcode.ALL_FORMATS)
                .build();
        cameraSource = new CameraSource.Builder(this, barcodeDetector)
                .setRequestedPreviewSize(800, 600)
                .setAutoFocusEnabled(true)
                .build();

        //Events

        surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                if (ActivityCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    //Make Request Runtime Permission
                    ActivityCompat.requestPermissions(MainActivity.this,
                            new String[]{Manifest.permission.CAMERA}, RequestCameraPermissionId);
                    return;
                }
                try {
                    cameraSource.start(surfaceView.getHolder());

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

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
                if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {

                    //Make Request Runtime Permission
                    ActivityCompat.requestPermissions(MainActivity.this,
                            new String[]{Manifest.permission.CAMERA}, RequestCameraPermissionId);
                    return;
                }
                try {
                    cameraSource.start();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                cameraSource.stop();
            }
        });

        barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {

            @Override
            public void release() {

            }

            @Override
            public void receiveDetections(Detector.Detections<Barcode> detections) {
                final SparseArray<Barcode> qrCodes = detections.getDetectedItems();
                if (qrCodes.size() != 0) {
                    txtShow.post(new Runnable() {
                        @Override
                        public void run() {
                            //stop camera
                            cameraSource.stop();

                            //create vibrate
                            Vibrator vibrator = (Vibrator) getApplicationContext().getSystemService(Context.VIBRATOR_SERVICE);
                            vibrator.vibrate(500);

                            //set result for Text View
                            txtShow.setText(qrCodes.valueAt(0).displayValue);
                            final String code = txtShow.getText().toString();
                            // surfaceView.setTop(200);
                            Intent intent = new Intent(MainActivity.this,InfoActivity.class);
                            //intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            intent.putExtra("code",code);
                            startActivity(intent);

                            final MediaPlayer mp = MediaPlayer.create(MainActivity.this, R.raw.barcode);
                            mp.start();