重力传感器监听器不工作

Posted 2023-04-13

【中文标题】重力传感器监听器不工作

【英文标题】：Gravity sensor listener not working

【发布时间】：2017-10-12 19:44:23

【问题描述】：

我想通过服务获取地球轴上的加速度计传感器数据。我在 *** 上的一篇文章中也读到了一种方法。但我有一个问题。

@Override
public void onSensorChanged(SensorEvent event) 
    Toast.makeText(this, "Hollyy shiiitt",Toast.LENGTH_SHORT);
    String acceldata = "";

    float[] gravityValues = null;
    float[] magneticValues = null;

    if (event.sensor.getType() == Sensor.TYPE_GRAVITY) 
        gravityValues = event.values.clone();
        Toast.makeText(this, "The gra data is " + String.valueOf(gravityValues), Toast.LENGTH_SHORT);
    

    if ((gravityValues != null) && (magneticValues != null)
            && (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)) 

        // float for use in conversion device relative acceleration to earth axis acceleration
        float[] deviceRelativeAcceleration = new float[4];
        deviceRelativeAcceleration[0] = event.values[0];
        deviceRelativeAcceleration[1] = event.values[1];
        deviceRelativeAcceleration[2] = event.values[2];
        deviceRelativeAcceleration[3] = 0;

        // Change the device relative acceleration values to earth relative values
        // X axis -> East
        // Y axis -> North Pole
        // Z axis -> Sky

        float[] R = new float[16], I = new float[16], earthAcc = new float[16];

        SensorManager.getRotationMatrix(R, I, gravityValues, magneticValues);

        float[] inv = new float[16];

        android.opengl.Matrix.invertM(inv, 0, R, 0);
        android.opengl.Matrix.multiplyMV(earthAcc, 0, inv, 0, deviceRelativeAcceleration, 0);

        acceldata = String.valueOf(lat) + "," + String.valueOf(lon) + "," +  String.valueOf(speed)+","+ String.valueOf(earthAcc[0]) + "," + String.valueOf(earthAcc[1]) + "," + String.valueOf(earthAcc[2])+ "," + String.valueOf(event.values[0])+ "," + String.valueOf(event.values[1])+ "," + String.valueOf(event.values[2]);

    

    //SDK  version check
    if(Build.VERSION.SDK_INT > 18) 
        File file;
        FileWriter filew; // Internal Storage writing
        try 
            file = new File(getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS) + "/" + filename); //Android 4.4 and above
            filew = new FileWriter(file, true); //true for append
            filew.write(acceldata + String.valueOf(gravityValues) + String.valueOf(magneticValues) +      "\n");
            filew.close();


         catch (Exception e) 
            e.printStackTrace();

        
    
    else
        String data = acceldata + "\n"  ;
        try 
            FileOutputStream fOut = openFileOutput("/" + filename,Context.MODE_APPEND);
            fOut.write(data.getBytes());
            fOut.close();
            Toast.makeText(getBaseContext(),"file saved",Toast.LENGTH_SHORT).show();
         catch (IOException e) 
            e.printStackTrace();
            Toast.makeText(getBaseContext(),"file not saved API < 19",Toast.LENGTH_SHORT).show();
        
    

位置发生变化的重力传感器的 if 语句不返回任何值，因此下一个语句也不起作用，因为重力值具有空值。

注册的传感器是

mAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mMagnetsensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
mGravity = sensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);

然后他们被注册为

int SamplingFrequency = 2 * 100000; // delay in microsecond. in this case 0.2 second
sensorManager.registerListener(this, mAccelerometer,SamplingFrequency);
sensorManager.registerListener(this, mMagnetsensor, SamplingFrequency);
sensorManager.registerListener(this,mGravity,SamplingFrequency);

我是应用程序开发的新手，因此我们将不胜感激。

【参考方案1】：

您的设备可能没有重力传感器。检查它是否可用

if (mSensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY) != null) 
        Toast.makeText(ActivitySensor1Availability.this, "Gravity AVAILABLE", Toast.LENGTH_SHORT).show();
     else 
        // Failure! No Gravity Sensor.
        Toast.makeText(ActivitySensor1Availability.this, "Failure! No Gravity Sensor", Toast.LENGTH_SHORT).show();
    

【讨论】：

当我在我的应用程序中尝试此代码时，屏幕上会出现 Gravity AVAILIBLE toast。还有其他建议吗？

是的，不做任何复杂的事情，检查你是否从重力传感器if (event.sensor.getType() == Sensor.TYPE_GRAVITY) System.out.println("X: " + event.values[0]); System.out.println("Y: " + event.values[1]); System.out.println("Z: " + event.values[2]); 获取值

不确定，但是当我添加 Linear_Acceleration 传感器时，重力传感器也开始抛出值。

你怎么能不确定。如果您使用 sn-p 并获取 x、y 和 z 值，那么它没有任何问题，下一步是您忽略这些值的轨道。如果您是新手，请将代码剥离到核心并检查每个步骤。创建传感器管理器，从传感器管理器获取重力传感器，注册它 onResume 和 onSensorChanged 检查是否从重力传感器获取输出