使用FirebaseUI代码制作listview适配器。它不会在适配器中调用getView()，也不会显示任何内容。发送数据似乎工作正常。
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.app.Fragment;
import android.text.format.DateFormat;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.hqs.tart.adapters.firebase.FirebaseListAdapter;
import com.hqs.tart.adapters.firebase.FirebaseListOptions;
import com.hqs.tart.tabletoproleplaytool.R;
import com.hqs.tart.models.ChatMessage;
/**
* A simple {@link Fragment} subclass.
* Activities that contain this fragment must implement the
* {@link GlobalChat.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {@link GlobalChat#newInstance} factory method to
* create an instance of this fragment.
*/
public class GlobalChat extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
private FirebaseListAdapter<ChatMessage> adapter;
ListView listOfMessages;
public GlobalChat() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment GlobalChat.
*/
// TODO: Rename and change types and number of parameters
public static GlobalChat newInstance(String param1, String param2) {
GlobalChat fragment = new GlobalChat();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
Query query = FirebaseDatabase.getInstance()
.getReference()
.child("chats")
.limitToLast(50);
FirebaseListOptions<ChatMessage> options = new FirebaseListOptions.Builder<ChatMessage>()
.setQuery(query, ChatMessage.class)
.setLayout(R.layout.fragment_chat)
.build();
/* adapter = new FirebaseListAdapter<ChatMessage>(options) {getActivity(), ChatMessage.class,
R.layout.fragment_chat, FirebaseDatabase.getInstance().getReference() */
adapter = new FirebaseListAdapter<ChatMessage>(options) {
@Override
protected void populateView(View v, ChatMessage model, int position) {
// Get references to the views of message.xml
TextView messageText = (TextView) v.findViewById(R.id.message_text);
TextView messageUser = (TextView) v.findViewById(R.id.message_user);
TextView messageTime = (TextView) v.findViewById(R.id.message_time);
// Set their text
messageText.setText(model.getMessageText());
messageUser.setText(model.getMessageUser());
Log.d("getFirebaseMessage", model.getMessageText());
// Format the date before showing it
messageTime.setText(DateFormat.format("dd-MM-yyyy (HH:mm:ss)",
model.getMessageTime()));
}
};
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_chat_list, container, false);
//set OnClick listener for button
FloatingActionButton fab = (FloatingActionButton) view.findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
EditText input = (EditText) getActivity().findViewById(R.id.input_box);
// Read the input field and push a new instance
// of ChatMessage to the Firebase database
FirebaseDatabase.getInstance()
.getReference()
.child("chats")
.push()
.setValue(new ChatMessage(input.getText().toString(),
FirebaseAuth.getInstance()
.getCurrentUser()
.getDisplayName())
);
Log.d("setFirebaseMessage", input.getText().toString());
// Clear the input
input.setText("");
listOfMessages.setAdapter(adapter);
}
});
listOfMessages = (ListView) view.findViewById(R.id.list_of_messages);
listOfMessages.setAdapter(adapter);
listOfMessages.setVisibility(View.VISIBLE);
return view;
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
GlobalChat.java
import android.arch.lifecycle.Lifecycle;
import android.arch.lifecycle.LifecycleOwner;
import android.arch.lifecycle.OnLifecycleEvent;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.hqs.tart.utils.firebase.ui.ChangeEventType;
/**
* This class is a generic way of backing an Android {@link android.widget.ListView} with a Firebase
* location. It handles all of the child events at the given Firebase location. It marshals received
* data into the given class type.
* <p>
* See the <a href="https://github.com/firebase/FirebaseUI-Android/blob/master/database/README.md">README</a>
* for an in-depth tutorial on how to set up the FirebaseListAdapter.
*
* @param <T> The class type to use as a model for the data contained in the children of the given
* Firebase location
*/
public abstract class FirebaseListAdapter<T> extends BaseAdapter implements FirebaseAdapter<T> {
private static final String TAG = "FirebaseListAdapter";
private final ObservableSnapshotArray<T> mSnapshots;
protected final int mLayout;
public FirebaseListAdapter(FirebaseListOptions<T> options) {
mSnapshots = options.getSnapshots();
mLayout = options.getLayout();
if (options.getOwner() != null) {
options.getOwner().getLifecycle().addObserver(this);
}
}
@Override
@OnLifecycleEvent(Lifecycle.Event.ON_START)
public void startListening() {
if (!mSnapshots.isListening(this)) {
mSnapshots.addChangeEventListener(this);
}
}
@Override
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
public void stopListening() {
mSnapshots.removeChangeEventListener(this);
notifyDataSetChanged();
}
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
void cleanup(LifecycleOwner source) {
source.getLifecycle().removeObserver(this);
}
@Override
public void onChildChanged(ChangeEventType type,
DataSnapshot snapshot,
int newIndex,
int oldIndex) {
notifyDataSetChanged();
}
@Override
public void onDataChanged() {
}
@Override
public void onError(DatabaseError error) {
Log.w(TAG, error.toException());
}
@Override
public ObservableSnapshotArray<T> getSnapshots() {
return mSnapshots;
}
@Override
public T getItem(int position) {
return mSnapshots.get(position);
}
@Override
public DatabaseReference getRef(int position) {
return mSnapshots.getSnapshot(position).getRef();
}
@Override
public int getCount() {
return mSnapshots.size();
}
@Override
public long getItemId(int i) {
// http://stackoverflow.com/questions/5100071/whats-the-purpose-of-item-ids-in-android-listview-adapter
return mSnapshots.getSnapshot(i).getKey().hashCode();
}
@Override
public View getView(int position, View view, ViewGroup viewGroup) {
if (view == null) {
view = LayoutInflater.from(viewGroup.getContext()).inflate(mLayout, viewGroup, false);
}
T model = getItem(position);
Log.d(TAG, "view obtained");
// Call out to subclass to marshall this model into the provided view
populateView(view, model, position);
return view;
}
/**
* Each time the data at the given Firebase location changes, this method will be called for
* each item that needs to be displayed. The first two arguments correspond to the mLayout and
* mModelClass given to the constructor of this class. The third argument is the item's position
* in the list.
* <p>
* Your implementation should populate the view using the data contained in the model.
*
* @param v The view to populate
* @param model The object containing the data used to populate the view
* @param position The position in the list of the view being populated
*/
protected abstract void populateView(View v, T model, int position);
}
FirebaseListAdapter.java
从未调用过getView（）。可以在logcat中确认。 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.hqs.tart.fragments.ChatFragment" >
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
android:id="@+id/fab"
android:tint="@android:color/white"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
app:fabSize="mini" />
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toLeftOf="@id/fab"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Input"
android:id="@+id/input_box"
/>
</android.support.design.widget.TextInputLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
android:layout_above="@id/fab"
android:dividerHeight="16dp"
android:divider="@android:color/transparent"
android:id="@+id/list_of_messages"
android:layout_marginBottom="16dp"/>
</RelativeLayout>
fragment_chat_list.xml
使用按钮和edittext列出布局。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
android:id="@+id/message_user"
android:textStyle="normal|bold" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/message_user"
android:layout_alignParentEnd="true"
android:id="@+id/message_time" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/message_user"
android:layout_alignParentStart="true"
android:layout_marginTop="5dp"
android:id="@+id/message_text"
android:textAppearance="@style/TextAppearance.AppCompat.Body1"
android:textSize="18sp" />
</RelativeLayout>
fragment_chat.xml 消息布局文件
我确定我没有正确设置适配器，但我不知道如何操作。不确定它是否是xml。
compileSDK 25
minSDK 19
我也是片段的新手，这可能有助于解决这个问题。
编辑：主要活动通过导航抽屉打开片段。不知道这是否有帮助。
答案 0 :(得分：0)
最终结果是我们的API实际上从未从数据库中接收任何内容。因此，这个问题。通过Android Studio连接到Firebase，它告诉我们我们错过了一个密钥。