How to scan a barcode from another Android application via Intents

How to scan a barcode from another Android application via Intents
透過其他的應用程式，使用其內部所提供的功能
    public Button.OnClickListener mScan = new Button.OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent("com.google.zxing.client.android.SCAN");
            intent.setPackage("com.google.zxing.client.android");
            // "SCAN_MODE" for all unknow code
            intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
            // use this method, can get the response by "onActivityResult( )"
            startActivityForResult(intent, 0);
        }
    };
    // receive the result    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == 0) {  // this line maybe can marked
            if (resultCode == RESULT_OK) {  // -1
                String contents = intent.getStringExtra("SCAN_RESULT");
                String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
                // Handle successful scan
            } else if (resultCode == RESULT_CANCELED) {  // 0
                // Handle cancel
            }
        }
    }

NMEA資訊

NMEA資訊
    // get location service
    LocationManager location = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    // set location update settings(time...)
     location.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,new LocationListener(){
        public void onLocationChanged(Location loc) {}
        public void onProviderDisabled(String provider) {}
        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status,Bundle extras) {}
    });
    // listen the NMEA information when change
    location.addNmeaListener(new NmeaListener() {
        public void onNmeaReceived(long timestamp, String nmea) {
            msg.append(nmea);
        }
    });

System Settings修改

System Settings修改
    // get screen off timeout time
    try {
        time = Settings.System.getInt(
            this.getContentResolver(), Settings.System.SCREEN_OFF_TIMEOUT);
    } catch (SettingNotFoundException e) {
        e.printStackTrace();
    }
    // modify timeout time to 15 seconds
    Settings.System.putInt(
        this.getContentResolver(), Settings.System.SCREEN_OFF_TIMEOUT, 15000);
    // modify rotation enable, 1: auto rotate on; 0: auto rotate off
    Settings.System.putInt(
        this.getContentResolver(), Settings.System.ACCELEROMETER_ROTATION, 1);
    // vibrator control
    vb = (Vibrator)getApplication().getSystemService(Service.VIBRATOR_SERVICE);
    vb.vibrate(1000*1000);    // parameter: vibrate time(ms)
    vb.cancel();    // stop