static final String ACTION_SCAN = "com.google.zxing.client.android.SCAN";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.scanner);
    }

    public void scanBar(View v) {
        try {
            Intent intent = new Intent(ACTION_SCAN);
            intent.putExtra("SCAN_MODE", "PRODUCT_MODE");
            startActivityForResult(intent, 0);
        } catch (ActivityNotFoundException anfe) {
            showDialog(BarcodeQr.this, "No Scanner Found", "Download a scanner code activity?", "Yes", "No").show();
        }
    }