如何正确运行后台服务？

Question

这是我的问题：我想添加一些背景通知给我的应用程序。

所以我想使用alarmanager和广播接收器，以重复任务。

但我该如何在一个活动中启动广播以便稍后在不同的活动中销毁它，而不会创建超过1个广播？

Answer 1

这里是我的通知代码，

public class NotificationService extends Service { 
// constant 
public static final long NOTIFY_INTERVAL = 30 * 1000; // 30 seconds 
long current_times; 
String c_time; 
// run on another Thread to avoid crash 
private Handler mHandler = new Handler(); 
// timer handling 
static HttpClient client = new DefaultHttpClient(); 
private Timer mTimer = null; 

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

@TargetApi(Build.VERSION_CODES.GINGERBREAD) @SuppressLint("NewApi") @Override 
public void onCreate() { 
    // cancel if already existed 

    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
    StrictMode.setThreadPolicy(policy); 
    SharedPreferences.Editor editor = getSharedPreferences("notification_oldtime", MODE_PRIVATE).edit(); 

    editor.putInt("old_trail_time", 0); 
    editor.putInt("old_sample_time", 0); 
    editor.putInt("old_neworder_time", 0); 

    editor.commit(); 

    if(mTimer != null) { 
     mTimer.cancel(); 
    } else { 
     // recreate new 
     mTimer = new Timer(); 
    } 
    // schedule task 
    mTimer.scheduleAtFixedRate(new TimeDisplayTimerTask(), 0, NOTIFY_INTERVAL); 
} 

public long current_time_get(){ 

    return current_times; 

} 





class TimeDisplayTimerTask extends TimerTask { 

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN) @Override 
    public void run() { 
     // run on another thread 

     mHandler.post(new Runnable() { 

      @Override 
      public void run() { 
       // display toast 

       DBAdapter.init(getApplicationContext()); 
       SharedPreferences prefs = getSharedPreferences("notification_oldtime", MODE_PRIVATE); 
       SharedPreferences.Editor editor = getSharedPreferences("notification_oldtime", MODE_PRIVATE).edit(); 

       int sample_order_new_count=0,trail_order_new_count=0,new_order_new_count=0,old_sample_order_count=0,old_trail_order_count=0,old_new_order_count=0; 
       String  search_read_URL=DBAdapter.getUrlName()+"/web/dataset/search_read"; 
       JSONArray sample_jsonarray,trail_jsonarray,new_jsonarray; 

       JSONObject jsonObj_sample,jsonObj_trail,jsonObj_newOrder; 
       StringEntity sample_entity,new_order_entity,trail_entity; 
       String responseBody_sample,responseBody_Trail,responseBody_NewOrder; 

      ResponseHandler<String> responseHandler = new BasicResponseHandler(); 

      try{ 

       DBAdapter.init(getApplicationContext()); 
       // notification for sample order 
       HttpPost sample_get = new HttpPost(search_read_URL); 
       HttpPost new_order_get = new HttpPost(search_read_URL); 
       HttpPost trail_get = new HttpPost(search_read_URL); 
       Log.d("service","start"); 
       sample_entity = new StringEntity(" {\"jsonrpc\":\"2.0\",\"method\":\"call\",\"params\":{\"model\":\"sale.sample.order\",\"fields\":[\"partner_id\",\"distributor_id\",\"marketing_person_id\",\"__last_update\"],\"domain\":[],\"context\":{\"lang\":\"en_US\",\"tz\":false,\"uid\":"+Integer.valueOf(DBAdapter.getMarketPersonUid())+",\"params\":{\"page\":0,\"limit\":500,\"view_type\":\"list\",\"model\":\"sale.sample.order\",\"menu_id\":378,\"action\":446,\"_push_me\":false},\"bin_size\":true},\"offset\":0,\"limit\":500,\"sort\":\"\"},\"id\":780343122}"); 
       new_order_entity=new StringEntity("{\"jsonrpc\":\"2.0\",\"method\":\"call\",\"params\":{\"model\":\"new.order.log\",\"fields\":[\"name\",\"partner_id\",\"distributor_id\",\"marketing_person_id\",\"__last_update\"],\"domain\":[],\"context\":{\"lang\":\"en_US\",\"tz\":false,\"uid\":"+Integer.valueOf(DBAdapter.getMarketPersonUid())+",\"params\":{\"page\":0,\"limit\":500,\"view_type\":\"list\",\"model\":\"new.order.log\",\"menu_id\":355,\"action\":418,\"_push_me\":false},\"bin_size\":true},\"offset\":0,\"limit\":500,\"sort\":\"\"},\"id\":674827326}"); 
       trail_entity=new StringEntity("{\"jsonrpc\":\"2.0\",\"method\":\"call\",\"params\":{\"model\":\"leather.trial.order\",\"fields\":[\"partner_id\",\"distributor_id\",\"marketing_person_id\",\"__last_update\"],\"domain\":[],\"context\":{\"lang\":\"en_US\",\"tz\":false,\"uid\":"+Integer.valueOf(DBAdapter.getMarketPersonUid())+",\"params\":{\"page\":0,\"limit\":500,\"view_type\":\"list\",\"model\":\"leather.trial.order\",\"menu_id\":375,\"action\":442,\"_push_me\":false},\"bin_size\":true},\"offset\":0,\"limit\":500,\"sort\":\"\"},\"id\":455581058}"); 

       sample_get.setHeader("Content-Type", "application/json"); 
       sample_get.setHeader("Cookie:","session_id="+DBAdapter.getSessionId()); 
       sample_get.setEntity(sample_entity); 

       new_order_get.setHeader("Content-Type", "application/json"); 
       new_order_get.setHeader("Cookie:","session_id="+DBAdapter.getSessionId()); 
       new_order_get.setEntity(new_order_entity); 

       trail_get.setHeader("Content-Type", "application/json"); 
       trail_get.setHeader("Cookie:","session_id="+DBAdapter.getSessionId()); 
       trail_get.setEntity(trail_entity); 


       responseBody_sample = client.execute(sample_get, responseHandler); 
       jsonObj_sample = new JSONObject(responseBody_sample); 
       JSONObject json=jsonObj_sample.getJSONObject("result"); 
       sample_jsonarray = json.getJSONArray("records");      

       responseBody_Trail=client.execute(trail_get, responseHandler); 
       jsonObj_trail=new JSONObject(responseBody_Trail); 
       JSONObject json1=jsonObj_trail.getJSONObject("result"); 
       trail_jsonarray = json1.getJSONArray("records");      

       responseBody_NewOrder=client.execute(new_order_get,responseHandler); 
       jsonObj_newOrder=new JSONObject(responseBody_NewOrder); 
       JSONObject json2=jsonObj_newOrder.getJSONObject("result"); 
       new_jsonarray=json2.getJSONArray("records"); 

       long server_Time = 0; 

       SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US); 


       String new_order_name="",trail_order_name="",sample_order_name=""; 

       for (int m = 0; m <trail_jsonarray.length(); m++) { 
        JSONObject c = trail_jsonarray.getJSONObject(m); 
        JSONArray cus_json_array=c.getJSONArray("partner_id"); 
        JSONArray market_person_json_array=c.getJSONArray("marketing_person_id"); 
        Date date = format.parse(String.valueOf(c.getString("__last_update"))); 
        server_Time = date.getTime(); 

       DBAdapter.init(getApplicationContext()); 
       long current_time=Long.parseLong(DBAdapter.getCurrentTime()); 
       Log.d("trail ct"+current_time,"st"+server_Time); 
       if(server_Time>current_time){ 
        trail_order_new_count++; 
        Log.d("trail_order cus name",cus_json_array.getString(1)); 
        trail_order_name=trail_order_name+" "+"Customer="+cus_json_array.getString(1)+"\n"+"Marketing Person="+market_person_json_array.getString(1); 
       } 
       else{ 
        m=trail_jsonarray.length(); 
       } 

       } 

       for (int m = 0; m <sample_jsonarray.length(); m++) { 
        JSONObject c = sample_jsonarray.getJSONObject(m); 
        JSONArray cus_json_array=c.getJSONArray("partner_id"); 
        JSONArray market_person_json_array=c.getJSONArray("marketing_person_id"); 
        Date date = format.parse(String.valueOf(c.getString("__last_update"))); 
        server_Time = date.getTime(); 

       DBAdapter.init(getApplicationContext()); 
       long current_time=Long.parseLong(DBAdapter.getCurrentTime()); 
       Log.d("sample ct"+current_time,"st"+server_Time); 
        if(server_Time>current_time){ 
        sample_order_new_count++; 
        Log.d("sample_order cus name",cus_json_array.getString(1)); 
        sample_order_name=sample_order_name+" "+"Customer="+cus_json_array.getString(1)+"\nMarketing Person="+market_person_json_array.getString(1); 
        } 

       else{ 
        m=trail_jsonarray.length(); 
       } 

        } 

       for (int m = 0; m <new_jsonarray.length(); m++) { 
        JSONObject c = new_jsonarray.getJSONObject(m); 
        JSONArray cus_json_array=c.getJSONArray("partner_id"); 
        JSONArray market_person_json_array=c.getJSONArray("marketing_person_id"); 
        Date date = format.parse(String.valueOf(c.getString("__last_update"))); 
        server_Time = date.getTime(); 

       DBAdapter.init(getApplicationContext()); 
       long current_time=Long.parseLong(DBAdapter.getCurrentTime()); 
       Log.d("newOrder ct"+current_time,"st"+server_Time); 
       if(server_Time>current_time){ 
        new_order_new_count++; 
        Log.d("new_order cus name",cus_json_array.getString(1)); 
        new_order_name=new_order_name+" "+"Customer="+cus_json_array.getString(1)+"\nMarketing Person="+market_person_json_array.getString(1); 
        } 

       else{ 
        m=trail_jsonarray.length(); 
       } 

        } 

       int newOrder_ID=100,sampleOrder_ID=200,trailOrder_ID=300; 
       final NotificationManager mgr= 
          (NotificationManager)getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE); 
        PendingIntent i2=PendingIntent.getActivity(getApplicationContext(), 1, 
         new Intent(getApplicationContext(),MainActivity.class), 
         0); 

       Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION); 



       if (new_order_new_count>prefs.getInt("old_neworder_time", 0)) { 
          NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext()); 
          mBuilder .setStyle(new NotificationCompat.BigTextStyle().bigText(new_order_name)); 
          mBuilder.setContentText(new_order_name); 
          mBuilder.setContentTitle(new_order_new_count+" New Orders"); 
          mBuilder.setSmallIcon(R.drawable.bkg_new_logo); 
          //mBuilder.setNumber(++numMsg); 
          mBuilder.setContentIntent(i2); 
          Log.d(String.valueOf(old_new_order_count),String.valueOf(new_order_new_count)); 
          if(old_new_order_count!=new_order_new_count){ 
          mBuilder.setSound(alarmSound); 
          } 
          mgr.notify(newOrder_ID, mBuilder.build()); 
          old_new_order_count=new_order_new_count; 
         editor.putInt("old_neworder_time", new_order_new_count); 
         editor.commit(); 
        } 
       if (sample_order_new_count>prefs.getInt("old_sample_time", 0)) { 
         NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext()); 
         mBuilder .setStyle(new NotificationCompat.BigTextStyle().bigText(sample_order_name)); 
         mBuilder.setContentText(sample_order_name); 
         mBuilder.setContentTitle(sample_order_new_count+" Sample Orders"); 
         mBuilder.setSmallIcon(R.drawable.bkg_new_logo); 
         //mBuilder.setNumber(++numMsg); 
         mBuilder.setContentIntent(i2); 
         if(old_sample_order_count!=sample_order_new_count){ 
         mBuilder.setSound(alarmSound); 
         } 
         mgr.notify(sampleOrder_ID, mBuilder.build()); 
         old_sample_order_count=sample_order_new_count; 
         editor.putInt("old_sample_time", sample_order_new_count); 
         editor.commit(); 
       } 
      if (trail_order_new_count>prefs.getInt("old_trail_time", 0)) { 
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext()); 
        mBuilder .setStyle(new NotificationCompat.BigTextStyle().bigText(trail_order_name)); 
        mBuilder.setContentText(trail_order_name); 
        mBuilder.setContentTitle(trail_order_new_count+" Trail Orders"); 
        mBuilder.setSmallIcon(R.drawable.bkg_new_logo); 
        //mBuilder.setNumber(++numMsg); 
        mBuilder.setContentIntent(i2); 
        if(old_trail_order_count!=trail_order_new_count){ 
        mBuilder.setSound(alarmSound); 
        } 
        mgr.notify(trailOrder_ID, mBuilder.build()); 
        old_trail_order_count=trail_order_new_count; 



        editor.putInt("old_trail_time", trail_order_new_count); 
        editor.commit(); 
      } 

      } 
       catch(Exception e){ 
        e.printStackTrace(); 
       } 
       } 

     }); 
    } 



} 
} 

可以使用NOTIFY_INTERVAL设定的周期时间。 在我的代码中，我使用了30秒。

每30秒我的服务在后台运行。

我希望这段代码能帮到你..

Answer 2

每个活动都应在每个活动“onResume”方法中注册广播接收器。不要忘记在注销。