我从firebase检索数据库中的数据。和shoscription herew up这个错误任何人都可以帮助我吗？这是我的mainactivity.java：
package com.example.infamouslegend.myapplication;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
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.ValueEventListener;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
FirebaseDatabase database;
DatabaseReference myRef ;
List<FireModel> list;
RecyclerView recycle;
Button view;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
view = (Button) findViewById(R.id.view);
recycle = (RecyclerView) findViewById(R.id.recycle);
database = FirebaseDatabase.getInstance();
myRef = database.getReference("Complaints");
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
list = new ArrayList<FireModel>();
for(DataSnapshot dataSnapshot1 :dataSnapshot.getChildren()){
FireModel value = dataSnapshot.getValue(FireModel.class);
FireModel fire = new FireModel();
String Description = value.getDescription();
String Date = value.getDate();
String MediaURL = value.getMediaURL();
fire.setDescription(Description);
fire.setDate(Date);
fire.setMediaURL(MediaURL);
list.add(fire);
}
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
Log.w("Hello", "Failed to read value.", error.toException());
Toast.makeText(MainActivity.this, "Failed to read value !" + error.toException(), Toast.LENGTH_SHORT).show();
}
});
view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
RecyclerAdapter recyclerAdapter = new RecyclerAdapter(list,MainActivity.this);
RecyclerView.LayoutManager recyce = new GridLayoutManager(MainActivity.this,2);
/// RecyclerView.LayoutManager recyce = new LinearLayoutManager(MainActivity.this);
// recycle.addItemDecoration(new GridSpacingItemDecoration(2, dpToPx(10), true));
recycle.setLayoutManager(recyce);
recycle.setItemAnimator( new DefaultItemAnimator());
recycle.setAdapter(recyclerAdapter);
}
});
}
}
这是我的firemodel.java：
package com.example.infamouslegend.myapplication;
/**
* Created by Infamous Legend on 10/15/2017.
*/
public class FireModel {
public String Description;
public String Date;
public String MediaURL;
public String getDescription() {
return Description;
}
public void setDescription(String description) {
this.Description = description;
}
public String getDate() {
return Date;
}
public void setDate(String date) {
this.Date = date;
}
public String getMediaURL() {
return MediaURL;
}
public void setMediaURL(String MediaURL) {
this.MediaURL = MediaURL;
}
}
和我的recycleradapter.java：
package com.example.infamouslegend.myapplication;
import android.content.Context;
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.squareup.picasso.Picasso;
import java.util.List;
/**
* Created by Infamous Legend on 10/15/2017.
*/
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.MyHoder>{
List<FireModel> list;
Context context;
public RecyclerAdapter(List<FireModel> list, Context context) {
this.list = list;
this.context = context;
}
@Override
public MyHoder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.card,parent,false);
MyHoder myHoder = new MyHoder(view);
return myHoder;
}
@Override
public void onBindViewHolder(MyHoder holder, int position) {
FireModel mylist = list.get(position);
holder.Description.setText(mylist.getDescription());
holder.Date.setText(mylist.getDate());
//holder.MediaURL.setText(mylist.getMediaURL());
//Picasso.with(context).load(MediaURL.get(position).getMediaURL()).resize(120, 60).into(MyHoder.MediaURL);
}
@Override
public int getItemCount() {
int arr = 0;
try{
if(list.size()==0){
arr = 0;
}
else{
arr=list.size();
}
}catch (Exception e){
}
return arr;
}
class MyHoder extends RecyclerView.ViewHolder{
TextView Description,Date;
//ImageView MediaURL;
public MyHoder(View itemView) {
super(itemView);
Description = (TextView) itemView.findViewById(R.id.vname);
Date= (TextView) itemView.findViewById(R.id.vemail);
//MediaURL= (ImageView) itemView.findViewById(R.id.thumbnail);
}
}
}
任何人都可以帮助我吗？我试图通过cardview从firebase数据库检索数据到recyclerview。提前致谢
这是我的firebase实时数据库规则：
{
"rules": {
".read": true,
".write":true
}
}