Question

我正在使用Firebase创建一个小型聊天应用程序。我希望ChildEventListener继续监听firebase数据库位置，尽管我的应用程序处于后台或退出。目前我正在注册它，当我的应用程序使用finish()退出或关闭时，之后我的所有ChildEventListener方法都没有调用onChildAdded或onChildChanged，尽管我没有调用{{ 1}}。我希望ChildEventListener始终在后台运行。无论如何都这样做？

Answer 1

使用服务来监听您的ChildEventListener

using (SqlConnection connection = new SqlConnection(connectionString))
{
    connection.Open();
command.CommandText = @"
 insert into YourTable (facility,rank) values ('classroom',@classroomRank);
 insert into YourTable (facility,rank) values ('labs',@labsRank);
 insert into YourTable (facility,rank) values ('lib',@libRank);
 insert into YourTable (facility,rank) values ('Cleanliness',@cleanlinessRank);

 command.Connection = connection;
 command.ExecuteNonQuery();
}

在清单中注册您的服务

    public class ChildEventListener extends Service {
        @Override
        public IBinder onBind(Intent intent) {
            return null;
        }
        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            //Adding a childevent listener to firebase                
            Firebase myFirebaseRef = new Firebase("FirebaseURL");
            myFirebaseRef.child("FIREBASE_LOCATION").addValueEventListener(new ValueEventListener() {

                @Override
                public void onDataChange(DataSnapshot snapshot) {
                    //Do something using DataSnapshot say call Notification
                }

                @Override
                public void onCancelled(FirebaseError error) {
                    Log.e("The read failed: ", error.getMessage());
                }
            });

          }

                @Override
                public void onCancelled(FirebaseError firebaseError) {
                    Log.e("The read failed: ", firebaseError.getMessage());
                }
            });

            return START_STICKY;
       }

  }

启动您的服务并收听childEvents，在何处/何时启动您的服务取决于您的聊天应用设计

Answer 2

尝试使用具有Firebase功能的Firebase云消息传递。

Firebase：虽然app退出，但仍会继续监听ChildEventListener

2 个答案: