扫描二维码后如何停止？

Question

我正在使用com.google.android.gms.vision依赖来扫描二维码。我面临的问题是它一次又一次地扫描二维码。我要它只扫描一次。

下面是我的代码：

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

    final SurfaceView cameraView = (SurfaceView) findViewById(R.id.camera_view);
    final TextView barcodeInfo = (TextView) findViewById(R.id.code_info);


    barcodeDetector =
            new BarcodeDetector.Builder(this)
                    .setBarcodeFormats(Barcode.QR_CODE)
                    .build();

    cameraSource = new CameraSource
            .Builder(this, barcodeDetector)
            .setAutoFocusEnabled(true)
            .setRequestedPreviewSize(640, 640)
            .build();

    cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            try {
                if (ActivityCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    // TODO: Consider calling
                    //    ActivityCompat#requestPermissions
                    // here to request the missing permissions, and then overriding
                    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                    //                                          int[] grantResults)
                    // to handle the case where the user grants the permission. See the documentation
                    // for ActivityCompat#requestPermissions for more details.
                    return;
                }
                cameraSource.start(cameraView.getHolder());
            } catch (IOException ie) {
                Log.e("CAMERA SOURCE", ie.getMessage());
            }
        }

        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        }

        @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> barcodes = detections.getDetectedItems();

            if (barcodes.size() != 0) {
                barcodeInfo.post(new Runnable() {    // Use the post method of the TextView
                    public void run() {
                        barcodeInfo.setText(    // Update the TextView
                                barcodes.valueAt(0).displayValue
                        );
                         QRData = barcodeInfo.getText().toString().trim();
                        Log.d("TAG", barcodeInfo.getText().toString().trim());


                    }
                });
            }


        }
    });

Answer 1

只需设置结果并在该活动中完成扫描时调用finish。在此之后，您需要在父活动(onActivityResult)中捕获结果。

PS。您需要使用startActivityForResult启动QRScanner活动。

编辑:如果QRScan是相同的活动停止相机。也许你需要隐藏这个表面。

干杯:)