Question

我创建了一个Activity来创建文件，并在传感器更改时向其写入传感器数据。我的代码如下：

public class AllSensors extends ActionBarActivity implements SensorEventListener{


Long startTime;
Long endTime;
Long currentTime;

private float ax,ay,az,gx,gy,gz,mx,my,mz;
Button start,stop,save;

private SensorManager sensorManager;

private Sensor accelerometer;
private Sensor gyroscope;
private Sensor magnetometer;

String content = "";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_all_sensors);

    start = (Button) findViewById(R.id.start);
    stop = (Button) findViewById(R.id.stop);
    save = (Button) findViewById(R.id.save);

    Typeface scribble = Typeface.createFromAsset(getAssets(), "fonts/warning.otf");

    start.setTypeface(scribble);
    start.setTextSize(80);

    stop.setTypeface(scribble);
    stop.setTextSize(80);

    save.setTypeface(scribble);
    save.setTextSize(80);

    sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);

    // register all the sensors
    if(sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) !=null ){
        accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sensorManager.registerListener(this,accelerometer,SensorManager.SENSOR_DELAY_NORMAL);
    }

    if(sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE) !=null ){
        gyroscope = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
        sensorManager.registerListener(this,gyroscope,SensorManager.SENSOR_DELAY_NORMAL);
    }

    if(sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) !=null ){
        magnetometer = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
        sensorManager.registerListener(this,magnetometer,SensorManager.SENSOR_DELAY_NORMAL);
    }


}

然后在saveData方法中我创建了一个文件（这个方法是按钮的onClick方法，当用户点击它时，它会创建并写入内容）：

    try{
        file = new File(Environment.getExternalStorageDirectory(),filename);

        fileOutputStream = new FileOutputStream(file);
        fileOutputStream.write(title.getBytes());
        fileOutputStream.write(content.getBytes());
        fileOutputStream.close();
    }catch (IOException e) {
        Toast.makeText(AllSensors.this,"An error occurred!",Toast.LENGTH_SHORT).show();
        return;
    }

在onSensorChanged方法中，当我取消注释当前注释的代码时，应用程序将编译但会在运行时停止：

public void onSensorChanged(SensorEvent event) {
    Sensor sensor = event.sensor;

    currentTime = System.currentTimeMillis();
    //if(currentTime >= startTime && currentTime <= endTime) {
        if (sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            ax = event.values[0];
            ay = event.values[1];
            az = event.values[2];

        } else if (sensor.getType() == Sensor.TYPE_GYROSCOPE) {
            gx = event.values[0];
            gy = event.values[1];
            gz = event.values[2];
        } else if (sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
            mx = event.values[0];
            my = event.values[1];
            mz = event.values[2];
        }

        //content += Long.toString(currentTime-startTime) + " " + Float.toString(ax) + " "
               // + Float.toString(ay) + " " + Float.toString(az) + " " + Float.toString(mx) + " "
                //+ Float.toString(my) + " " + Float.toString(mz) + " " + Float.toString(gx) + " "
                //+ Float.toString(gy) + " " + Float.toString(gz) + "/n";
   // }

}

有谁知道它为什么？最初我只是写了内容+ = ax + ay ....但它也会在运行时停止。

谢谢！

Answer 1

我自己解决了。问题是我将字段startTime，currentTime和endTime声明为Long而不是long。因此，比较和字符串追加失败。

android onSensorChanged在运行时无法正常工作

1 个答案: