从加速计传感器写入文件 - android

Question

I'm facing a technician code problem. I want to write all the values I get from TotalAccelerate into my .txt file through Toggle button. the code is now writing only one value at a time once I toggle the button. How can I manually write and stop writing into the file? Thanks in advance.

FileOutputStream fileOutputStream;
double TotalAccelerate; //I made it global variable
ArrayList<Double> list;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    list = new ArrayList<Double>();

     //for Accelermeter
    sm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    sensorText = (TextView) findViewById(R.id.sensor);
    accelermeter = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    sm.registerListener(this, accelermeter, SensorManager.SENSOR_DELAY_NORMAL);
    mDetector = new GestureDetectorCompat(this, new MyGestureListener());


    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        File Root = Environment.getExternalStorageDirectory();
        File dir = new File(Root.getAbsolutePath() + "/MyApp");
        if (!dir.exists()) {
            dir.mkdir();
        }
        File file = new File(dir, "MyMessage.txt");
        try {
            fileOutputStream = new FileOutputStream(file, true);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

    } else {
        Toast.makeText(getApplicationContext(), "SDcard not found", Toast.LENGTH_LONG).show();
    }

    OnStore = (ToggleButton) findViewById(R.id.onStore);
    OnStore.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            if (OnStore.isChecked()){
                try {
                    for(TotalAccelerate : list){
                         String space = "\n";
                        byte[] convert = space.getBytes();
                        fileOutputStream.write(convert);
                        String finalData;
                        finalData = String.valueOf(TotalAccelerate);
                        fileOutputStream.write(finalData.getBytes());
                    }
                     Toast.makeText(getApplicationContext(), "Message saving", Toast.LENGTH_LONG).show();

                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }if (!OnStore.isChecked()){
                try {
                    fileOutputStream.flush();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    fileOutputStream.close();
                     //added
                    list.clear();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Toast.makeText(getApplicationContext(),"Message Stopped.",Toast.LENGTH_LONG).show();

            }


        }

    });
}// end OnCreate method

//Find the total acccerleration from the three sensors, 
  then write the values into a file for off-line analysis
@Override
public final void onSensorChanged(SensorEvent event) {
    // The light sensor returns a single value.
    // Many sensors return 3 values, one for each axis.
    double xx = event.values[0];
    double yy = event.values[1];
    double zz = event.values[2];
    TotalAccelerate = Math.round(Math.sqrt(Math.pow(xx, 2)
            + Math.pow(yy, 2)
            + Math.pow(zz, 2)));
    Log.i(DEBUG, "Accelerometer = " + TotalAccelerate);

    //  list = new ArrayList<Double>();
    list.add(TotalAccelerate);
    findPeaks(list);
    sensorText.setText("Total: " + list);
    Log.i(DEBUG, "Total " + list);

}

Answer 1

You are creating a new List each time the sensor changes, with the line:-

list = new ArrayList<Double>();

Move this to the start of your program, and empty the list once you have written it to the file. You will also need to synchronize the places where the list is modified.