从服务更新 UI(使用处理程序?)

当我收到通知时，我正在尝试更新 FirstActivity 中的 UI，但被 runOnUiThread 、Runnable 和 Handler 弄糊涂了.这是我所拥有的:我正在运行 FirstActivity 和 NotificationService.当 NotificationService 收到通知时，它会更新 FirstActivity UI.

I am trying to update my UI in FirstActivity when I receive a notification but is confused by runOnUiThread , Runnable and Handler. Here is what I have: I am running FirstActivity and NotificationService. When NotificationService reeives a notification, it will update FirstActivity UI.

我还有另一个服务 AlarmService 正在运行.第一个活动

I also have another service AlarmService running. First Activity

@Override
public void onResume() {
      super.onResume();
      //some other code for alarm service
}

通知服务

    //on receiving notification
    private void showNotification(String text) {

   //Get activity
   Class<?> activityClass = null;
     try {
         activityClass = Class.forName("com.pakage.FirstActivity");
         contextActivity = (Activity) activityClass.newInstance();

         //Update UI on FirstActivity not working
         contextActivity.runOnUiThread(new Runnable() {
             public void run()
             { 
               Looper.prepare();
               TextView tv = (TextView ) contextActivity.findViewById(R.id.notifyTest);
               Looper.loop();

             }
             });

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

            //Shows the notification
            Notification n = new Notification();    
            //... etc   
}

我不断收到 looper.prepare 错误.我需要在我的 FirstActivity 中添加额外的代码吗?

I keep getting looper.prepare error. Do I need to put extra codes in my FirstActivity?