Question

我是android新手。我想在手机发抖时播放音频文件。我知道加速代码。但是当我编写媒体播放器代码时，我没有从我的设备获得任何输出。

public void onSensorChanged(SensorEvent event) {
        // TODO Auto-generated method stub
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            getAccelerometer(event);

            MediaPlayer mPlayer1 = MediaPlayer.create(null, R.raw.hello);

            try {
                mPlayer1.prepare();
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            mPlayer1.start();
        }
    }

Answer 1

使用以下课程进行摇晃听众，

import java.util.List;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;

public class ShakeListener implements SensorEventListener{

        private MyShakeListener mOnShakeListener = null;  
        private SensorManager mSensorManager;
        private double mTotalForcePrev;
        private double mForceThreshHold = 1.5f;

        private List<Sensor> mSensors;
        private Sensor mAccelerationSensor;

        public ShakeListener(SensorManager sm){
                mSensorManager = sm;

        mSensors = mSensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER);
        if(mSensors.size() > 0) {
                mAccelerationSensor = mSensors.get(0);
                mSensorManager.registerListener(this, mAccelerationSensor, SensorManager.SENSOR_DELAY_GAME);
        }

        }

        public void setForceThreshHold(double threshhold){
                mForceThreshHold = threshhold;
        }
        public double getForceThreshHold(){
                return mForceThreshHold;
        }

        public void onAccuracyChanged(Sensor sensor, int accuracy) {}

    public void onSensorChanged(SensorEvent event) {    
          double totalForce = 0.0f;
          totalForce += Math.pow(event.values[0]/SensorManager.GRAVITY_EARTH, 2.0);
          totalForce += Math.pow(event.values[1]/SensorManager.GRAVITY_EARTH, 2.0);
          totalForce += Math.pow(event.values[2]/SensorManager.GRAVITY_EARTH, 2.0);
          totalForce = Math.sqrt(totalForce);

          if((totalForce < mForceThreshHold) && (mTotalForcePrev > mForceThreshHold)) {
                  OnShake();
          }

          mTotalForcePrev = totalForce;
    }

    public void setOnShakeListener(MyShakeListener listener) 
    {
        mOnShakeListener = listener;
    }  

    private void OnShake()
    {  
        if(mOnShakeListener!=null) 
        {  
                mOnShakeListener.onShake();  
        }  
    }  

}

public interface MyShakeListener {  
    public abstract void onShake();  
}

并在主类上添加侦听器类，如下所示，

public class MainActivity extends Activity
{

MediaPlayer defaultPlayer;
@Override
    public void onCreate(Bundle bundle)
    {
        super.onCreate(bundle);
        setContentView(R.layout.playerscree);
          ShakeListener myShake = new           ShakeListener((SensorManager)getSystemService(Context.SENSOR_SERVICE));
            myShake.setForceThreshHold(1.9);

            myShake.setOnShakeListener(new MyShakeListener()
            {
                @Override
                public void onShake() 
                {
               // do ur work here...
                  defaultPlayer= MediaPlayer.create(getApplicationContext(), R.raw.music);
                  defaultPlayer.start();
                }
            });
}

Answer 2

创建Context时，您应该提供MediaPlayer。 E.g。

MediaPlayer.create(getApplicationContext(), R.raw.hello);

此外，建议事先创建一个MediaPlayer。

Answer 3

像这样修改你的代码。希望这有效。

MediaPlayer mPlayer1 = MediaPlayer.create(null, R.raw.hello);

到

MediaPlayer mPlayer1 = MediaPlayer.create(getApplicationContext(), R.raw.hello);

加速度计不工作

3 个答案: