How do I get the Accelerometer and Magenetometer values simultaniously?

[SunainaDG]

Like when my device senses a jerk, it has both change in accelerometer and magnetometer values. I need both of their values of the 3 axes separately. That is X,Y,Z for accelerometer separately and X,Y,Z for magnetometer separately .

I have already tried the below code, but it does not work.Please help me on this.

//code below:

    private void StartListening()
    {
        CrossDeviceMotion.Current.SensorValueChanged += (s, a) =>
        {
            if (lastUpdate > DateTime.MinValue)
            { 

                    //I feel like there should be some kind of a type casting of the value here but I have no 
                       idea how to do that.

                    if (a.SensorType == MotionSensorType.Accelerometer)
                    {
                        CurrentData.X = ((MotionVector)a.Value).X;
                        CurrentData.Y = ((MotionVector)a.Value).Y;
                        CurrentData.Z = ((MotionVector)a.Value).Z;
                    }

                    if (a.SensorType == MotionSensorType.Magnetometer)
                    {
                        CurrentData.Pitch = ((MotionVector)a.Value).X;
                        CurrentData.Roll = ((MotionVector)a.Value).Y;
                        CurrentData.Yaw = ((MotionVector)a.Value).Z;
                    }
            }
            else
            {
                 //I feel like there should be some kind of a type casting of the value here but I have no 
                       idea how to do that.

                if (a.SensorType == MotionSensorType.Accelerometer)
                {
                    LastData.X = ((MotionVector)a.Value).X;
                    LastData.Y = ((MotionVector)a.Value).Y;
                    LastData.Z = ((MotionVector)a.Value).Z;
                }

                if (a.SensorType == MotionSensorType.Magnetometer)
                {
                    LastData.Pitch = ((MotionVector)a.Value).X;
                    LastData.Roll = ((MotionVector)a.Value).Y;
                    LastData.Yaw = ((MotionVector)a.Value).Z;
                }
                lastUpdate = currentTime;
            }

        };
    }