Question

我想从我的Firebase数据库中检索信息到一个名为fragment_schedule.xml的片段中的recyclerview中，每个条目的布局在blog_row.xml中，以下是我的代码示例；

fragment_schedule.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ScheduleFragment"
android:orientation="vertical"
android:background="@drawable/blackboard2">

<android.support.v7.widget.RecyclerView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/myrecycleView">

</android.support.v7.widget.RecyclerView>

blog_row.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
app:cardCornerRadius="12dp"
android:elevation="90dp"
android:layout_margin="7dp">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:orientation="vertical"
    >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/post_date"
        android:text="Date"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/post_time"
        android:text="Time"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/post_event"
        android:text="Event"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/post_moderator"
        android:text="Moderator"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/post_venue"
        android:text="Venue"/>


</LinearLayout>

</android.support.v7.widget.CardView>

ScheduleFragment.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
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.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

public class ScheduleFragment extends Fragment {
private RecyclerView mBlogList;
private DatabaseReference mDatabase;


public ScheduleFragment() {
    // Required empty public constructor
}

@Override
public void onStart() {
    super.onStart();
    FirebaseRecyclerAdapter<Schedule,ScheduleViewHolder>firebaseRecyclerAdapter = new 
FirebaseRecyclerAdapter<Schedule, ScheduleViewHolder>
            (Schedule.class,R.layout.blog_row,ScheduleViewHolder.class, mDatabase) {
        @Override
        protected void populateViewHolder(ScheduleViewHolder viewHolder, Schedule 
model, int position) {
            viewHolder.setEvent_name( model.getEvent_name() );
            viewHolder.setEvent_date( model.getEvent_date() );
            viewHolder.setEvent_moderator( model.getEvent_moderator() );
            viewHolder.setEvent_time( model.getEvent_time() );
            viewHolder.setEvent_venue( model.getEvent_venue() );
        }
    };

    mBlogList.setAdapter( firebaseRecyclerAdapter );
}
public static class ScheduleViewHolder extends RecyclerView.ViewHolder{
    View mView;
    public ScheduleViewHolder(View itemView){
        super(itemView);
        mView = itemView;
    }
    public void setEvent_name(String event_name){
        TextView post_event = (TextView)mView.findViewById( R.id.post_event );
        post_event.setText( event_name );
    }
    public void setEvent_moderator(String event_moderator){
        TextView post_moderator = (TextView)mView.findViewById( R.id.post_moderator );
        post_moderator.setText( event_moderator );
    }
    public void setEvent_time(String event_time){
        TextView post_time = (TextView)mView.findViewById( R.id.post_time );
        post_time.setText( event_time );
    }
    public void setEvent_venue(String event_venue){
        TextView post_venue = (TextView)mView.findViewById( R.id.post_venue );
        post_venue.setText( event_venue );
    }

    public void setEvent_date(String event_date) {
        TextView post_date = (TextView)mView.findViewById( R.id.post_date );
        post_date.setText( event_date );
    }
}
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_schedule, container, false);

    mDatabase = FirebaseDatabase.getInstance().getReference().child("schedule");
    mDatabase.keepSynced(true);
    mBlogList = (RecyclerView) view.findViewById(R.id.myrecycleView);
    mBlogList.setHasFixedSize(true);
    mBlogList.setLayoutManager(new LinearLayoutManager(getContext()));

    return view;
}

Schedule.java

public class Schedule {

private String event_name;
private String event_date;
private String event_moderator;
private String event_time;
private String event_venue;

public Schedule(String event_name, String event_date, String event_moderator, String 
event_time, String event_venue) {
    this.event_name = event_name;
    this.event_date = event_date;
    this.event_moderator = event_moderator;
    this.event_time = event_time;
    this.event_venue = event_venue;
}

public String getEvent_name() {
    return event_name;
}

public void setEvent_name(String event_name) {
    this.event_name = event_name;
}

public String getEvent_date() {
    return event_date;
}

public void setEvent_date(String event_date) {
    this.event_date = event_date;
}

public String getEvent_moderator() {
    return event_moderator;
}

public void setEvent_moderator(String event_moderator) {
    this.event_moderator = event_moderator;
}

public String getEvent_time() {
    return event_time;
}

public void setEvent_time(String event_time) {
    this.event_time = event_time;
}

public String getEvent_venue() {
    return event_venue;
}

public void setEvent_venue(String event_venue) {
    this.event_venue = event_venue;
}

public Schedule()
{

}
}

一切似乎都很好，应用程序可以运行，但是片段为空。我一次又一次地检查了代码，找不到我可能出错的地方。请帮助

Answer 1

您使用的是旧版本的FirebaseUI，需要删除mBlogList.setHasFixedSize(true);，以便数据将显示在页面中。

这是旧版本中的错误，请在此处查看：

https://github.com/firebase/FirebaseUI-Android/issues/204

在片段中将Firebase信息检索到recyclerview中

1 个答案: