android - 是否可以在 Activity 环境之外使用加速度计？

Question

嗨，我是新来的(我只编程了几个月，所以我的把握不稳)，正在尝试创建一个游戏，让玩家的头像随着加速度计移动，他们必须躲避屏幕上的东西(从上到下的角度)。我已经创建了一个 gameScreen 类来绘制头像、背景和敌人，我正在尝试为加速度计创建一个类来告诉 gameScreen 将头像移动到哪里。目前我的类包含用于扩展 AndroidGame 框架的加速度计的代码，但由于它不是 Activity 并且没有 onCreate，我不确定如何设置加速度计。有没有办法做到这一点，还是我只是在做这一切都错了？

这是我目前所拥有的(显然是不完整的)。

import edu.austincc.testlearnand.SplashLoadingScreen;
import edu.austincc.framework.Screen;
import edu.austincc.testlearnand.Assets;
import edu.austincc.framework.implementation.AndroidGame;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;

public class BuffaloStampede extends AndroidGame implements SensorEventListener {
TextView textView;
SensorManager manager;
double[] gravity = new double[3];
public double[] linear_acceleration = new double[3];

boolean firstTimeCreate = true;

@Override
public Screen getInitScreen() {

    if (firstTimeCreate) {
        Assets.loadBS(this);
        firstTimeCreate = false;
    }

    return new SplashLoadingScreen(this);

}

@Override
public void onBackPressed() {
    getCurrentScreen().backButton();
}


@Override
public void onResume() {
    super.onResume();

    Assets.theme.play();

}

@Override
public void onPause() {
    super.onPause();
    Assets.theme.pause();
    manager.unregisterListener(this);

}







public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    textView = new TextView(this);

    manager = (SensorManager) this.getSystemService(Context.SENSOR_SERVICE);
    if (manager.getSensorList(Sensor.TYPE_ACCELEROMETER).size() == 0) {
        textView.setText("No accelerometer installed");
    } else {
        Sensor accelerometer = manager.getSensorList(
                Sensor.TYPE_ACCELEROMETER).get(0);
        if (!manager.registerListener(this, accelerometer,
                SensorManager.SENSOR_DELAY_NORMAL)) {
            textView.setText("Couldn't register accelerometer listener");
        }
    }
    setContentView(textView);
}

@Override
public void onSensorChanged(SensorEvent event) {
    // alpha is calculated as t / (t + dT)
    // with t, the low-pass filter's time-constant
    // and dT, the event delivery rate

    final double alpha = 0.8;

    gravity[0] = alpha * gravity[0] + (1 - alpha) * event.values[0];
    gravity[1] = alpha * gravity[1] + (1 - alpha) * event.values[1];
    gravity[2] = alpha * gravity[2] + (1 - alpha) * event.values[2];

    linear_acceleration[0] = event.values[0] - gravity[0];
    linear_acceleration[1] = event.values[1] - gravity[1];
    linear_acceleration[2] = event.values[2] - gravity[2];

}

public double[] getGravity() {
    return gravity;
}

public double[] getLinear_acceleration() {
    return linear_acceleration;
}

public void setGravity(double[] gravity) {
    this.gravity = gravity;
}

public void setLinear_acceleration(double[] linear_acceleration) {
    this.linear_acceleration = linear_acceleration;
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // nothing to do here
}
}

Answer 1

在您的加速度计类中创建一个带有 Context 参数的构造函数，并使用此参数实例化一个 SensorManager。

public MyAccelerometerClass implements SensorEventListener
{
     private SensorManager sensorManager;

     public MyAccelerometerClass(Context context)
     {
          sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE); 
     }

     // codes 
 }