我想提醒服務

Question

我想從eventreminder創建事件提醒警報。但爲什麼警報沒有顯示？

我在清單中有android.permission.SYSTEM_ALERT_WINDOW。

這是eventreminder服務的代碼：

package com.example.android.eventreminder; 

import android.app.AlertDialog; 
import android.app.Notification; 
import android.app.NotificationManager; 
import android.app.PendingIntent; 
import android.content.Intent; 
import android.database.Cursor; 
import android.util.Log; 
import android.view.WindowManager; 

/* This class is responsible for notification when an alarm and proximity alert are fired 
* Sets up pending intent which is used by notification system. 
* Pending intent contains intent to start ViewReminder Activity when notification is clicked*/ 
public class EventReminderService extends WakeReminderIntentService { 
    private eventDB mDbHelper; 
    private String notificationTitle; 

    public EventReminderService() { 
     super("EventReminderService"); 
    } 

    @Override 
    void doReminderWork(Intent intent) { 
     /* Status bar notification */ 
     /* when the notification is selected from status bar, 
     * ViewReminder activity will be started using rowId as part of 
     * pending intent. ViewReminder activity will be used to display 
     * event data, to delete event and to snooze time-based event*/ 
     AlertDialog d = new AlertDialog.Builder(this) 
       .setTitle("tanchulai") 
       .setMessage("bucuo de tanchulai") 

       .create(); 

     d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); 
     d.show(); 


     Long rowId = intent.getExtras().getLong(eventDB.KEY_ROWID); 

     NotificationManager mgr = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); 

     /* Add reminder activity will started when notification is selected */ 
     Intent notificationIntent = new Intent(this, ViewReminder.class); 
     notificationIntent.putExtra(eventDB.KEY_ROWID, rowId); 

     int rowID = rowId.intValue(); 
     /* set pending intent */ 
     PendingIntent pi = PendingIntent.getActivity(this, rowID, notificationIntent, 
     PendingIntent.FLAG_ONE_SHOT); 
     Log.d("TAG", "PI in ERSer for: "+rowID); 
     /* set notification for status bar */ 
     Notification note=new Notification(android.R.drawable.stat_sys_warning, 
             getString(R.string.notify_new_task_message), 
             System.currentTimeMillis()); 


     mDbHelper = new eventDB(this); 
     mDbHelper.open(); 
     Cursor notificationData = mDbHelper.fetchEvent(rowId); 
     /* get title of the event*/ 
     notificationTitle = notificationData.getString(
       notificationData.getColumnIndexOrThrow(eventDB.KEY_TITLE)); 

     note.setLatestEventInfo(this, notificationTitle, 
           getString(R.string.notify_new_task_message), pi); 

     notificationData.close(); 
     mDbHelper.close(); 

     /* Set default notification sound */ 
     note.defaults |= Notification.DEFAULT_SOUND; 
     /* Cancel notification after selection by user */ 
     note.flags |= Notification.FLAG_AUTO_CANCEL; 

     int id = (int)((long)rowId); 
     /* produce notification on status bar */ 
     mgr.notify(id, note); 

    } 
} 

Answer 1

服務從活動單獨運行（以便在後臺運行）。所以服務沒有窗口，你不能顯示對話框或烤麪包。您應該將數據發送到活動，並在那裏處理。

您可以使用BroadcastReceiver從Service發送數據到Activity。