地面服務中的通知

Question

我對通知和forgroundtasks有幾個問題。首先，這是我的服務：

public class NFCUploadService extends Service implements MeasureDataPostCallback { 
    private static final int IMAGE_SEND_NFC_SERVICE_ID = 100; 

    @Override 
    public void onCreate() { 
     super.onCreate(); 
    } 

    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     if (intent.getAction().equals(ForegroundServiceTags.STARTFOREGROUND_ACTION.getValue())) { 
      String email = intent.getStringExtra(Globals.KEY_EMAIL); 
      String password = intent.getStringExtra(Globals.KEY_PASSWORD); 
      String year = intent.getStringExtra(Globals.KEY_YEAR); 
      String month = intent.getStringExtra(Globals.KEY_MONTH); 
      String day = intent.getStringExtra(Globals.KEY_DATE); 
      String hour = intent.getStringExtra(Globals.KEY_HOUR); 
      String minute = intent.getStringExtra(Globals.KEY_MINUTE); 
      String value = intent.getStringExtra(Globals.KEY_VALUE); 
      String mealTime = intent.getStringExtra(Globals.KEY_MEALTIME); 
      String mood = intent.getStringExtra(Globals.KEY_MOOD); 
      File imageFile = null; 

      if(intent.getStringExtra(Globals.KEY_FILE_PATH) != null) { 
       imageFile = new File(intent.getStringExtra(Globals.KEY_FILE_PATH)); 
      } 

      MeasureDataPostTask task = new MeasureDataPostTask(email, password, year, month, day, hour, minute, value, mealTime, mood, imageFile); 
      task.setCallback(this); 
      task.execute(this); 

      Notification.Builder builder = new Notification.Builder(this); 
      builder.setContentTitle("Progress"); 
      builder.setContentText("Sending Data..."); 
      builder.setTicker("Notification!"); 
      builder.setWhen(System.currentTimeMillis()); 
      builder.setSmallIcon(R.drawable.ic_launcher); 
      builder.setOngoing(true); 
      Notification notification = builder.build(); 

      this.startForeground(IMAGE_SEND_NFC_SERVICE_ID, notification); 
     } 

     return super.onStartCommand(intent, flags, startId); 
    } 

    @Override 
    public IBinder onBind(Intent intent) { 
     return null; 
    } 

    @Override 
    public void onMeasureDataPostCompleted(StatusMeasureDataPost status, MeasureDataPostPOJO measureDataPostPojo) { 
     Notification.Builder builder = new Notification.Builder(this); 
     builder.setContentTitle("Progress"); 
     builder.setTicker("Notification!"); 
     builder.setWhen(System.currentTimeMillis()); 
     builder.setSmallIcon(R.drawable.ic_launcher); 
     builder.setOngoing(true); 

     switch(status) { 
     case ERROR_CONNECTION_FAILED: 
      builder.setContentText("Connection Failed"); 
      break; 
     case ERROR_DB_CONNECTION_FAILED: 
      builder.setContentText("DB Connection Failed"); 
      break; 
     case ERROR_IO_EXCEPTION: 
      builder.setContentText("IO Exception"); 
      break; 
     case ERROR_JSON_EXCEPTION: 
      builder.setContentText("JSON Exception"); 
      break; 
     case ERROR_MEASUREDATA_ALREADY_EXISTS: 
      builder.setContentText("Data already exists"); 
      break; 
     case ERROR_PROTOCOL_EXCEPTION: 
      builder.setContentText("Protocol Exception"); 
      break; 
     case ERROR_WRONG_PARAMETERS: 
      builder.setContentText("Wrong Parameters"); 
      break; 
     case MEASUREDATA_TRANSFER_SUCCESSFUL: 
      builder.setContentText("Transfer complete"); 
      break; 
     } 

     Notification notification = builder.build(); 

     this.startForeground(IMAGE_SEND_NFC_SERVICE_ID, notification); 
    } 
} 

只要我的AsyncTask（MeasureDataPostTask）還沒有完成，我想我的服務是殺不死的。這意味着我不希望用戶能夠在Android設備的通知選項卡中清除通知。

在AsyncTask完成之後（即當調用onMeasureDataPostCompleted時）我想要更改我的通知，我想打印出結果消息並使通知可用。用戶應該能夠在AsyncTask完成但不在運行時刷新通知。我怎麼能做到這一點？

後來我還想添加一個機制，當AsyncTask由於缺少互聯網連接而失敗時，每5分鐘重複一次AsyncTask。

Answer 1

首先，你應該從onStartCommand()打電話給startForeground()。

要重複AsyncTask，您應該設置一個鬧鐘，重新發送您的意圖。