Java Firebase数据库查询未显示在屏幕上
我有一个类,我在其中显示用户拥有的朋友列表。但是,当我尝试运行此操作时,RecylerView不会向当前用户显示他们的好友 朋友片段Java Firebase数据库查询未显示在屏幕上,java,android,firebase,firebase-realtime-database,Java,Android,Firebase,Firebase Realtime Database,我有一个类,我在其中显示用户拥有的朋友列表。但是,当我尝试运行此操作时,RecylerView不会向当前用户显示他们的好友 朋友片段 import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.os.Bundle; import android.support.annotation.NonNull; import andr
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.widget.AlertDialogLayout;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
import de.hdodenhof.circleimageview.CircleImageView;
/**
* A simple {@link Fragment} subclass.
*/
public class FriendsFragment extends Fragment {
private RecyclerView mFriendsList;
private DatabaseReference mFriendsDatabase;
private DatabaseReference mUsersDatabase;
private FirebaseAuth mAuth;
private String mCurrent_user_id;
private View mMainView;
public FriendsFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
mMainView = inflater.inflate(R.layout.fragment_friends, container, false);
mAuth = FirebaseAuth.getInstance();
mCurrent_user_id = mAuth.getCurrentUser().getUid();
mFriendsDatabase = FirebaseDatabase.getInstance().getReference().child("Friends").child(mCurrent_user_id);
mUsersDatabase= FirebaseDatabase.getInstance().getReference().child("Users");
mFriendsList= (RecyclerView)mMainView.findViewById(R.id.friends_list);
mFriendsList.setHasFixedSize(true);
mFriendsList.setLayoutManager(new LinearLayoutManager(getContext()));
mFriendsDatabase.keepSynced(true);
return mMainView;
}
public void onStart() {
super.onStart();
startListening();
}
public void startListening() {
Query queryFriends = FirebaseDatabase.getInstance()
.getReference()
.child("Friends")
.child(mCurrent_user_id)
.limitToLast(50);
FirebaseRecyclerOptions<Friends> options =
new FirebaseRecyclerOptions.Builder<Friends>()
.setQuery(queryFriends, Friends.class)
.build();
FirebaseRecyclerAdapter<Friends, FriendsViewHolder> friendsRecyclerViewAdapter = new FirebaseRecyclerAdapter<Friends, FriendsViewHolder>(options) {
@NonNull
@Override
public FriendsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.friends_single_layout, parent, false);
return new FriendsViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull final FriendsViewHolder holder, int position, @NonNull Friends model) {
holder.setDate(model.getDate());
final String list_user_id= getRef(position).getKey();
mUsersDatabase.child(list_user_id).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.hasChild("online") && dataSnapshot.hasChild("name") && dataSnapshot.hasChild("thumb_image") && dataSnapshot.hasChild("status")) {
final String username = dataSnapshot.child("name").getValue().toString();
String userThumb = dataSnapshot.child("thumb_image").getValue().toString();
String userStatus = dataSnapshot.child("status").getValue().toString();
holder.setName(username);
holder.setUserImage(userThumb);
holder.setUserStatus(userStatus);
boolean userOnline = (boolean) dataSnapshot.child("online").getValue();
holder.setUserOnline(userOnline);
mUsersDatabase.keepSynced(true);
mFriendsDatabase.keepSynced(true);
holder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
CharSequence options[] = new CharSequence[]{"Open profile", "Send Message"};
AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
builder.setTitle("Select Options");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (which == 0) {
Intent profileIntent = new Intent(getContext(), ProfileActivity.class);
profileIntent.putExtra("user_id", list_user_id);
startActivity(profileIntent);
}
if (which == 1) {
Intent chatIntent = new Intent(getContext(), ChatActivity.class);
chatIntent.putExtra("user_id", list_user_id);
chatIntent.putExtra("user_name", username);
mUsersDatabase.keepSynced(true);
mFriendsDatabase.keepSynced(true);
startActivity(chatIntent);
}
}
});
builder.show();
}
});
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
};
mFriendsList.setAdapter(friendsRecyclerViewAdapter);
friendsRecyclerViewAdapter.startListening();
}
public static class FriendsViewHolder extends RecyclerView.ViewHolder {
View mView;
public FriendsViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setDate(String date){
TextView userStatusView = (TextView) mView.findViewById(R.id.user_single_status);
userStatusView.setText(date);
}
public void setName(String name){
TextView userNameView= (TextView)mView.findViewById(R.id.user_single_name);
userNameView.setText(name);
}
public void setUserImage(String thumb_image){
CircleImageView userImageView = (CircleImageView) mView.findViewById(R.id.user_single_image);
Picasso.get().load(thumb_image).placeholder(R.drawable.accountpicture).into(userImageView);
}
public void setUserStatus(String status){
TextView userStatView= (TextView)mView.findViewById(R.id.user_single_status);
userStatView.setText(status);
}
public void setUserOnline(boolean online_status){
ImageView userOnlineView= (ImageView) mView.findViewById(R.id.user_single_online_icon);
ImageView userOffilneView= (ImageView) mView.findViewById(R.id.user_single_offline_icon);
if(online_status){
userOnlineView.setVisibility(View.VISIBLE);
userOffilneView.setVisibility(View.INVISIBLE);
}
else{
userOnlineView.setVisibility(View.INVISIBLE);
userOffilneView.setVisibility(View.VISIBLE);
}
}
}
}
导入android.app.AlertDialog;
导入android.content.DialogInterface;
导入android.content.Intent;
导入android.os.Bundle;
导入android.support.annotation.NonNull;
导入android.support.v4.app.Fragment;
导入android.support.v7.widget.AlertDialogLayout;
导入android.support.v7.widget.LinearLayoutManager;
导入android.support.v7.widget.RecyclerView;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ImageView;
导入android.widget.TextView;
导入com.firebase.ui.database.FirebaseRecyclerAdapter;
导入com.firebase.ui.database.FirebaseRecyclerOptions;
导入com.google.firebase.auth.FirebaseAuth;
导入com.google.firebase.database.DataSnapshot;
导入com.google.firebase.database.DatabaseError;
导入com.google.firebase.database.DatabaseReference;
导入com.google.firebase.database.FirebaseDatabase;
导入com.google.firebase.database.Query;
导入com.google.firebase.database.ValueEventListener;
导入com.squareup.picasso.picasso;
导入de.hdodenhof.circleimageview.circleimageview;
/**
*一个简单的{@link Fragment}子类。
*/
公共类FriendsFragment扩展了片段{
私人回收网站;
私有数据库参考mFriendsDatabase;
私有数据库参考mUsersDatabase;
私人消防队;
私有字符串mCurrent\u user\u id;
私人视图;
公益碎片(){
//必需的空公共构造函数
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
//为该碎片膨胀布局
mMainView=充气机。充气(R.layout.fragment\u friends,container,false);
mAuth=FirebaseAuth.getInstance();
mCurrent_user_id=mAuth.getCurrentUser().getUid();
mfriendsddatabase=FirebaseDatabase.getInstance().getReference().child(“朋友”).child(mCurrent\u user\u id);
mUsersDatabase=FirebaseDatabase.getInstance().getReference().child(“用户”);
mFriendsList=(RecyclerView)mMainView.findViewById(R.id.friends\u列表);
mFriendsList.setHasFixedSize(true);
setLayoutManager(新的LinearLayoutManager(getContext());
mFriendsDatabase.keepSynced(true);
返回视图;
}
public void onStart(){
super.onStart();
惊人的倾听();
}
公营机构{
查询queryFriends=FirebaseDatabase.getInstance()
.getReference()
.儿童(“朋友”)
.child(当前用户id)
.limitToLast(50);
FirebaseRecyclerOptions选项=
新的FirebaseRecyclerOptions.Builder()
.setQuery(queryFriends,Friends.class)
.build();
FirebaseRecyclerAdapter好友RecycleServiceAdapter=新的FirebaseRecyclerAdapter(选项){
@非空
@凌驾
public FriendsViewHolder onCreateViewHolder(@NonNull ViewGroup parent,int viewType){
View=LayoutInflater.from(parent.getContext())
.充气(R.layout.friends\u single\u layout,parent,false);
返回新的FriendsViewHolder(视图);
}
@凌驾
受保护的无效onBindViewHolder(@NonNull final FriendsViewHolder holder,int position,@NonNull Friends model){
holder.setDate(model.getDate());
最终字符串列表_user_id=getRef(position).getKey();
mUsersDatabase.child(list\u user\u id).addValueEventListener(新的ValueEventListener()){
@凌驾
public void onDataChange(@NonNull DataSnapshot DataSnapshot){
if(dataSnapshot.hasChild(“联机”)&&dataSnapshot.hasChild(“名称”)&&dataSnapshot.hasChild(“拇指图像”)&&dataSnapshot.hasChild(“状态”)){
最终字符串username=dataSnapshot.child(“name”).getValue().toString();
字符串userThumb=dataSnapshot.child(“thumb_image”).getValue().toString();
字符串userStatus=dataSnapshot.child(“status”).getValue().toString();
holder.setName(用户名);
holder.setUserImage(userThumb);
holder.setUserStatus(用户状态);
boolean userOnline=(boolean)dataSnapshot.child(“online”).getValue();
holder.setUserOnline(userOnline);
mUsersDatabase.keepSynced(true);
mFriendsDatabase.keepSynced(true);
holder.mView.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
CharSequence选项[]=新的CharSequence[]{“打开配置文件”,“发送消息”};
AlertDialog.Builder=新建AlertDialog.Builder(getContext());
builder.setTitle(“选择选项”);
setItems(选项,新的DialogInterface.OnClickListener(){
@凌驾
public void onClick(DialogInterface dialog,int which){
if(which==0){