如何在同一Java类中将两个传感器管理器用于加速度计和磁力计

Question

I have Two programs (Accelerometer and Magnetometer) both using the Sensor Manager. I think the problem is when i combine these two programs into one to get their data, The onResume() is getting confused between which Sensor Manager to use in between the program. Please do let me know if i can use two different requestListener for the two programs in The same Class. The code is Below, Please do see The OnResume() method.

@Override

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        mToolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(mToolbar);
        //Accelerometer--------------------------------------------------
        initializeViews();
        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        if (sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null) {
            // success! we have an accelerometer
            accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
            sensorManager.registerListener( this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
            vibrateThreshold = accelerometer.getMaximumRange() / 2;
        } else {

            // fail we dont have an accelerometer!
        }

        //initialize vibration
        v = (Vibrator) this.getSystemService(Context.VIBRATOR_SERVICE);
        //----------------------------------------------------------------
        //Magnetometer------------------------------------------------------
        uT = (TextView) findViewById(R.id.textView2);
        max = (TextView) findViewById(R.id.textView3);
        min = (TextView) findViewById(R.id.textView4);
        // Get an instance of the sensor service
        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mMagnetometerSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);


        PackageManager PM = this.getPackageManager();
        boolean gyro = PM.hasSystemFeature(PackageManager.FEATURE_SENSOR_GYROSCOPE);
        boolean light = PM.hasSystemFeature(PackageManager.FEATURE_SENSOR_LIGHT);


        if (gyro) {

            if (light) {
                Toast.makeText(getApplicationContext(), "Both light and gyroscope sensors are present", Toast.LENGTH_LONG).show();
            } else
                Toast.makeText(getApplicationContext(), "Only gyroscope sensor is present", Toast.LENGTH_LONG).show();

        }
        //-----------------------------------------------------------------------------------

    }
    //Accelerometer-----------------------------------------------------------

    private void initializeViews() {
        currentX = (TextView) findViewById(R.id.currentX);
        currentY = (TextView) findViewById(R.id.currentY);
        currentZ = (TextView) findViewById(R.id.currentZ);


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_first, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        if (id == R.id.home_button){
            startActivity(new Intent(this, MainActivity.class));
        }

        return super.onOptionsItemSelected(item);
    }

    protected void onResume() {
        super.onResume();
        sensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
        mSensorManager.registerListener(this, mMagnetometerSensor, SensorManager.SENSOR_DELAY_NORMAL);
    }


    //onPause() unregister the accelerometer for stop listening the events

    protected void onPause() {
        super.onPause();
        sensorManager.unregisterListener( this);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        // clean current values


        // display the current x,y,z accelerometer values

        // display the max x,y,z accelerometer values
        displayMaxValues();


        // get the change of the x,y,z values of the accelerometer

        deltaXX = Math.abs(lastX - event.values[0]);
        deltaX= deltaXX/2;
        deltaYY = Math.abs(lastY - event.values[1]);
        deltaY = deltaYY/2;
        deltaZZ = Math.abs(lastZ - event.values[2]);
        deltaZ= deltaZZ/2;

        // if the change is below 2, it is just plain noise

        if (deltaX < 2)
            deltaX = 0;
        if (deltaY < 2)
            deltaY = 0;
        if ((deltaX > vibrateThreshold) || (deltaY > vibrateThreshold) || (deltaZ > vibrateThreshold)) {
            v.vibrate(1);
        }
        //Magnetometer--------------------------------------------------
            float angularXSpeed = event.values[0];
            DecimalFormat decimalFormatuT = new DecimalFormat("00.00");
            Double CurrentuT = Double.parseDouble(decimalFormatuT.format(angularXSpeed));

            if (angularXSpeed > max1) {
                max1 = angularXSpeed;
                DecimalFormat decimalFormatMaxMag = new DecimalFormat("00.00");
                Double MaxMag = Double.parseDouble(decimalFormatMaxMag.format(max1));
                max.setText("Max " + "" + MaxMag);
            } else if (angularXSpeed < min1) {
                min1 = angularXSpeed;
                DecimalFormat decimalFormatMinMag = new DecimalFormat("00.00");
                Double MinMag = Double.parseDouble(decimalFormatMinMag.format(min1));
                min.setText("Min " + "" + MinMag);
            }

        //------------------------------------------------------------

    }

    private void displayMaxValues() {



        if (deltaX > deltaXMax) {
            deltaXMax = deltaX;
            maxX = (TextView) findViewById(R.id.maxX);
            DecimalFormat decimalFormat = new DecimalFormat("00.00");
            Double MaxXX = Double.parseDouble(decimalFormat.format(deltaXMax));
            maxX.setText(Double.toString(MaxXX));

        }

        if (deltaY > deltaYMax) {
            deltaYMax = deltaY;
            maxY = (TextView) findViewById(R.id.maxY);
            DecimalFormat decimalFormat = new DecimalFormat("00.00");
            Double MaxYY = Double.parseDouble(decimalFormat.format(deltaYMax));
            maxY.setText(Double.toString(MaxYY));

        }

        if (deltaZ > deltaZMax) {
            deltaZMax = deltaZ;
            maxZ = (TextView) findViewById(R.id.maxZ);
            DecimalFormat decimalFormat = new DecimalFormat("00.00");
            Double MaxZZ = Double.parseDouble(decimalFormat.format(deltaZMax));
            maxZ.setText(Double.toString(MaxZZ));


        }

    }




    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
    //Accelerometer--------------------------------------------------------------
}

Answer 1

you can access all sensors on device by using SensorManager Instance. just modify your code as following, and call register into onResume only as :

protected void onCreate(Bundle savedInstanceState) {
  ....
  mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
  if ((accelerometer  = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null ) {...}
  if ((magnetometer   = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) != null ) {...}
  ....
}
// register the sensors only one time within onResume not in onCreate
@Override
protected void onResume() {
    super.onResume();
    mSensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_UI);
    mSensorManager.registerListener(this, magnetometer, SensorManager.SENSOR_DELAY_UI);
  }

also you have to check the sensor type in method onSensorChanged as following:

onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
      ....
}
if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD){
      ....
}