當活動重新打開時，Asynctask停止在textView中顯示數據

我正在嘗試使用asynctask來持續更新我的主界面中的textview。還有另一個按鈕可以打開另一個活動。當我啓動應用程序時，asyntask啓動並向textview顯示數據，但是當我點擊另一個按鈕打開另一個活動並單擊返回按鈕返回aysnctask正在運行的上一個活動時，它停止向TextView中。當活動重新打開時，Asynctask停止在textView中顯示數據

你能幫助mem解決這個問題或者建議其他方法嗎？謝謝。

代碼MainActivity：

Button about; 
TextView tempData; 
Context context = this; 
AllSensorData sensorData; 


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

    about=(Button)findViewById(R.id.hAbout); 

    tempData=(TextView)findViewById(R.id.tempData); 

    sensorData=new AllSensorData(tempData,getApplicationContext()); 
    sensorData.execute("http://192.168.1.177/"); 


    about.setOnClickListener(new OnClickListener() 
    { 
     @Override 
     public void onClick(View v) 
     { 
      Intent i =new Intent(getApplicationContext(),AboutActivity.class);    
      startActivity(i); 
     } 
    });

代碼aynctask類：

public class AllSensorData extends AsyncTask<String, byte[], String>{ 

    TextView temp; 

    Context context; 

    public AllSensorData(TextView temp,Context context) { 
      this.temp=temp; 
      this.context=context; 
    } 


    InputStream nis; 
    OutputStream nos; 
    BufferedReader in; 
    DefaultHttpClient httpclient =new DefaultHttpClient(); 
    URL url; 
    URLConnection urlconn=null; 
    InputStreamReader isn; 

    @Override 
    protected String doInBackground(String... params) { 
     // TODO Auto-generated method stub 

     HttpClient httpclient = new DefaultHttpClient(); 
     HttpResponse response; 
      try { 


       //this method is working for data only 
       while(true){//while connected 
      HttpGet httpget =new HttpGet("http://192.168.1.177/"); 
      response = httpclient.execute(httpget); 
      in=new BufferedReader(new InputStreamReader(response.getEntity().getContent())); 

       String msgFromServer = in.readLine();//read the lines coming from the socket 
       byte[] theByteArray = msgFromServer.getBytes();//store the bytes in an array 
       publishProgress(theByteArray);//update the publishProgress 


        if(isCancelled()){ 
         break; 
        } 
       } 


      } catch (ClientProtocolException e) { 

      } catch (IOException e) { 

      } 
     return null; 
    } 

    private boolean alreadyDisplayedNotification = false; 

    private boolean already =false ; 

    protected void onProgressUpdate(byte[]... values) { 
     super.onProgressUpdate(values); 
     String command=new String(values[0]);//get the String from the recieved bytes 
     String[] parts= command.split(","); 
     String part1=parts[0]; 


     temp.setText(part1); 

    } 
}

來源

2016-02-04 akshay270494

加入的onResume方法您的TextView更新代碼; – justDroid

閱讀關於它的活動生命週期，並顯示以保存活動狀態 –

我使用了onResumed方法，並且仍然當重新打開活動 – akshay270494