How to code for SensorEventListener in Activity class by Xamarin

I'm get trouble for this topic.

First I have reference Java code.

private SensorEventListener mySensorEventListener = new SensorEventListener(){


public void onAccuracyChanged(Sensor sensor, int accuracy) {//onAccuracyChanged
  }
  @Override
  public void onSensorChanged(SensorEvent event) {
   if(event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){//Determine whether the change in the acceleration sensor
    float [] values = event.values;  //Captured data
    tvX.setText("acceleration on the x-axis direction is："+values[0]);  
    tvY.setText("acceleration on the y-axis direction is"+values[1]); 
    tvZ.setText("acceleration on the z-axis direction is"+values[2]);  
   }  
  }
 };

It direct write under Activity class.

And I want copy this idea.

But C# and JAve is different. I don't know how to come ture this idea on Activity class.

I'm try this idea.

 public class MainActivity : Activity
    {

        private SensorManager sensormanager;
        private Sensor sensor_Accelerometer, sensor_MAGNETIC_FIELD;
        private SensorEvent Sensor_Evenlistener_1 ;




   protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

              sensormanager = (SensorManager)GetSystemService(SensorService);  //Obtain services from a sensor system
        sensor_Accelerometer = sensormanager.GetDefaultSensor(SensorType.Accelerometer);
        sensor_MAGNETIC_FIELD = sensormanager.GetDefaultSensor(SensorType.MagneticField);
        sensormanager.RegisterListener(Sensor_Evenlistener_1, sensor_Accelerometer.Handle, SensorDelay.Normal);
        sensormanager.RegisterListener(Sensor_Evenlistener_1, sensor_MAGNETIC_FIELD.Handle, SensorDelay.Normal);                                      // Key

But about RegisterListener this part.

Always appear fail message Compiler.

Please help me. How to come true this idea by Xamarin.

Thanks!