一次写入一个值

Posted 2023-02-26

【中文标题】一次写入一个值

【英文标题】：Write one value at a time

【发布时间】：2017-06-09 07:02:06

【问题描述】：

我正在尝试将 onSensorChanged( ) 方法的总加速度写入文件。我处理写入文件的代码有问题。 我的文件只显示一个值。我想查看 所有 值，直到我切换按钮停止写入。您能否指出我的代码中的错误在哪里。提前致谢。

 ToggleButton OnStore;   
 private GestureDetectorCompat mDetector;
FileOutputStream fileOutputStream;
@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
     OnStore = (ToggleButton) findViewById(R.id.onStore);
    mDetector = new GestureDetectorCompat(this, new MyGestureListener());
    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);

     OnStore.setOnClickListener(new OnClickListener() 
        @Override
        public void onClick(View view) 
            if (OnStore.isChecked())
                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);
                        String space =" ";
                        byte[] convert = space.getBytes();
                        fileOutputStream.write(convert);
                        String finalData;
                        finalData = String.valueOf(TotalAccelerate);
                        fileOutputStream.write(finalData.getBytes());
                        //fileOutputStream.close();
                        Toast.makeText(getApplicationContext(),"Message saving",Toast.LENGTH_LONG).show();

                     catch (FileNotFoundException e) 
                        e.printStackTrace();
                     catch (IOException e) 
                        e.printStackTrace();
                    
                else 
                    Toast.makeText(getApplicationContext(),"SDcard not found",Toast.LENGTH_LONG).show();
                
            
            if (!OnStore.isChecked())
                try 
                    fileOutputStream.flush();
                    fileOutputStream.close();
                    Toast.makeText(getApplicationContext(),"Message Stopped.",Toast.LENGTH_LONG).show();

                 catch (IOException e) 
                    e.printStackTrace();
                
            

        
    );


  double TotalAccelerate;
  ArrayList<Double> list;

 @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,"Total "+ TotalAccelerate);
    list = new ArrayList<Double>();
    list.add(TotalAccelerate);

    //  findPeaks(list);
    sensorText.setText("Total: " + list);
    Log.i(DEBUG, "Total " + list);

【参考方案1】：

您每次在onSensorChanged(SensorEvent event) 中重新初始化您的list

您必须在onCreate 或if (OnStore.isChecked()) 之后执行此操作才能显示开始和停止之间的所有结果

更新

在onClick(View view)中添加行list = new ArrayList<Double>();

     OnStore.setOnClickListener(new OnClickListener() 
        @Override
        public void onClick(View view) 
            if (OnStore.isChecked())
                list = new ArrayList<Double>();
                ...

并删除onSensorChanged(SensorEvent event)中的list = new ArrayList<Double>();

更新 2

在onCreate(Bundle savedInstanceState) 中添加行list = new ArrayList<Double>(); 而不是onClick(View view)

@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    list = new ArrayList<Double>();
    ...

你所有的值都在list

for(double TotalAccelerate : list)
    System.out.println(TotalAccelerate);

【讨论】：

我还是没明白。请你写一个代码来说明一下。

它可以工作，但是当我的 OnStore.isChecked 时，我需要拥有 **TotalAccelerate ** 的所有值。我怎样才能做到这一点。我觉得我需要一个线程。

我的意思是我希望所有值都存储在我的 .txt 文件中。我还是没听懂。