Android-RecyclerView无法正常工作 [英] Android - RecyclerView not working
问题描述
我正在尝试从Firebase数据库中检索数据,但是我的屏幕没有显示任何内容.我没有看到任何错误,所以我不知道为什么什么也没发生.谁能发现任何错误?在Stackoverflow成员的帮助下,我遵循了FirebaseUI指南.数据应在屏幕上显示街道和用户
I am trying to retrieve data from my Firebase database, but my screen is not showing anything. I don't see any errors so I don't know why nothing is happening. Can anyone spot any mistakes? I followed the FirebaseUI guide with some help from a stackoverflow member. The data should show the street and the user on the screen
片段:
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_stopandmap, container, false);
Query keyQuery = FirebaseDatabase.getInstance().getReference("/Addresses/Street 10/users");
DatabaseReference dataRef = FirebaseDatabase.getInstance().getReference("/User");
recyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerview);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
FirebaseRecyclerOptions<User> options = new FirebaseRecyclerOptions.Builder<User>()
.setIndexedQuery(keyQuery, dataRef, User.class)
.build();
FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<User, BetViewHolder>(options) {
@Override
public BetViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_row, parent, false);
return new BetViewHolder(view);
}
@Override
protected void onBindViewHolder(BetViewHolder holder, int position, User model) {
holder.setUserName(model.getUsername());
}
};
recyclerView.setAdapter(adapter);
return rootView;
}
public static class BetViewHolder extends RecyclerView.ViewHolder {
TextView tw;
public BetViewHolder(View itemView) {
super(itemView);
tw = (TextView) itemView.findViewById(R.id.usersTextview);
}
public void setUserName(String username) {
tw.setText("Hej" + username);
Log.e("Activity", "In Vehicle " + username);
}
}
用户类别:
public class User {
private String username;
private String usertype;
public User() {
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUsertype() {
return usertype;
}
public void setUsertype(String usertype) {
this.usertype = usertype;
}
}
推荐答案
In version 3.0 of FirebaseUI, you need to explicitly call startListening()
& stopListening()
on the adapter to instruct it to start/stop retrieving data from the database.
适配器生命周期-在以前的版本中,适配器开始监听实例化后立即进行,并进行了
cleanup()
调用以停止听.在3.x中,您必须显式调用startListening()
,然后stopListening()
或将LifecycleOwner
传递给选项构建器.
Adapter Lifecycle - in previous versions the adapters began listening immediately upon instantiation and had a
cleanup()
call to stop listening. In 3.x you must explicitly callstartListening()
andstopListening()
or pass aLifecycleOwner
to the options builder.
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