FirebaseRecyclerAdapter无法填充结果

我想在RecyclerView中使用FirebaseRecyclerAdapter并不使用FirebaseListAdapter来显示EmployeeDetails。 但活动没有显示任何内容

火力地堡：

"EmployeeDetails" : { "3dTxdRlBVUZ0jzH4U5MR4TOKZnD2" : { "address" : "na", "name" : "na", "phoneNum" : "na", "type" : "Employee" }, "wEz6XRMQcAU9cQJLR82uVwVMrC83" : { "address" : "na", "name" : "na", "phoneNum" : "na", "type" : "Admin" } } 

ViewEmployeeDetails.java

 public class ViewEmployeeDetails extends AppCompatActivity { RecyclerView recyclerView; RecyclerView.LayoutManager layoutManager; DatabaseReference employee; FirebaseRecyclerAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_view_employee_details); recyclerView=(RecyclerView)findViewById(R.id.listEmployee); recyclerView.setHasFixedSize(true); layoutManager=new LinearLayoutManager(this); recyclerView.setLayoutManager(layoutManager); loadEmployee(); } private void loadEmployee() { employee= FirebaseDatabase.getInstance().getReference("EmployeeDetails"); adapter=new FirebaseRecyclerAdapter ( UserInformation.class, R.layout.employee_list_activity, EmployeeViewHolder.class, employee ) { @Override protected void populateViewHolder(EmployeeViewHolder viewHolder, UserInformation model, int position) { viewHolder.txtEmployeeName.setText(model.getName()); viewHolder.txtEmployeeType.setText(model.getType()); viewHolder.txtEmployeeAddress.setText(model.getAddress()); viewHolder.txtEmployeePhone.setText(model.getPhoneNum()); } }; adapter.notifyDataSetChanged(); recyclerView.setAdapter(adapter); } } 

EmployeeViewHolder.java

 package com.example.intel.employeesite.Other.ViewHolders; import android.support.v7.widget.RecyclerView; import android.view.View; import android.widget.TextView; import com.example.intel.employeesite.R; public class EmployeeViewHolder extends RecyclerView.ViewHolder { public TextView txtEmployeeName,txtEmployeeAddress,txtEmployeePhone,txtEmployeeType; public EmployeeViewHolder(View itemView) { super(itemView); txtEmployeeName=(TextView) itemView.findViewById(R.id.txtEmployeeName); txtEmployeeAddress=(TextView) itemView.findViewById(R.id.txtEmployeeAddress); txtEmployeePhone=(TextView) itemView.findViewById(R.id.txtEmployeePhone); txtEmployeeType=(TextView) itemView.findViewById(R.id.txtEmployeeType); } } 

activity_view_employee_details.xml

employee_list_activity.xml

我试着解决它但没有任何反应。 有人帮助我。

Answer 1

要解决此问题，首先要使适配器变量为全局变量：

 private FirebaseRecyclerAdapter adapter; 

然后，您需要在onStart()和onStop()方法中添加以下代码行：

 @Override protected void onStart() { super.onStart(); adapter.startListening(); } @Override protected void onStop() { super.onStop(); if(adapter != null) { adapter.stopListening(); } } 

因为适配器使用侦听器来检查数据库更改，所以为了使其工作，我们需要先开始侦听。 当我们关闭应用程序时，我们需要停止收听。

我已经在我的一个video中解释过如何逐步实现这一目标。