Android Firebase，Recyclerview 的服务器端过滤答案

【问题标题】：Android Firebase, server side filtering for RecyclerviewAndroid Firebase，Recyclerview 的服务器端过滤
【发布时间】：2016-10-22 05:12:18
【问题描述】：

以下是我的 firebase 数据结构

{
  "ticketing" : {
    "1476639649079-mahto" : {
      "agentId" : 0,
      "agent_status" : "1_Dispatched",
      "approverId" : 0,
      "contractorId" : 0,
      "dateTime" : "16-10-2016 13:40 PM",
      "priority" : "MEDIUM",
      "requester" : {
        "issue" : "issue 3",
        "location" : "location 3",
        "priority" : "Medium",
        "shop" : "shop 3",
        "site" : "site 3",
        "userInfo" : {
          "email" : "m@gmail.com",
          "firstname" : "mahto",
          "isLoggedin" : true,
          "lastname" : "pancha",
          "loggedin" : true,
          "number" : "123123123",
          "password" : "q",
          "role" : "fieldagent",
          "userid" : "2",
          "username" : "q"
        }
      },
      "requesterId" : 2,
      "status" : "Incoming",
      "ticketNumber" : "1476639649079-mahto"
    },
    "1476741838857-mahto" : {
      "agentId" : 1,
      "agent_status" : "1_Incoming",
      "approverId" : 0,
      "contractorId" : 0,
      "dateTime" : "17-10-2016 18:03 PM",
      "priority" : "HIGH",
      "requester" : {
        "issue" : "Description 3",
        "location" : "Location 3",
        "priority" : "HIGH",
        "shop" : "shop 3",
        "site" : "site 3",
        "userInfo" : {
          "email" : "m@gmail.com",
          "firstname" : "mahto",
          "isLoggedin" : true,
          "lastname" : "pancha",
          "loggedin" : true,
          "number" : "123123123",
          "password" : "q",
          "role" : "fieldagent",
          "userid" : "2",
          "username" : "q"
        }
      },
      "requesterId" : 2,
      "status" : "Incoming",
      "ticketNumber" : "1476741838857-mahto"
    }
  }
}

数据库引用

mDatabase = FirebaseDatabase.getInstance().getReference().child("ticketing");
        mDatabase.orderByChild("agent_status").equalTo("1_Incoming");

并附加到recyclerview适配器

 mAdapter = new FirebaseRecyclerAdapter<Ticket, AgentTicketHolder>(Ticket.class, R.layout.agent_ticket_cardview, AgentTicketHolder.class, mDatabase) { .. }

我的预期结果是我只会得到一个节点，即 1476741838857-mahto，它的 agent_status 值等于 1_Incoming。

但我在我的 recylerview 中获得了两个节点。

【问题讨论】：

在您的问题中发布 EventListener，检查您的 EventListener 是否添加到数据库引用或查询中

标签： android firebase firebase-realtime-database firebaseui

【解决方案1】：

当您调用过滤方法时，Firebase SDK 会为结果查询返回一个新对象。因此，您需要捕获对该对象的引用并将 that 传递给适配器：

mDatabase = FirebaseDatabase.getInstance().getReference().child("ticketing");

Query query = mDatabase.orderByChild("agent_status").equalTo("1_Incoming");

mAdapter = new FirebaseRecyclerAdapter<Ticket, AgentTicketHolder>
    (Ticket.class, R.layout.agent_ticket_cardview, AgentTicketHolder.class, query) { .. }

【讨论】：