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Ich versuche, einen benutzerdefinierten Adapter zu bauen, basierend auf einer Liste, die ich von Firebase bekommen sollte.kann nicht abrufen Liste Feuerbasis
Grundsätzlich setze ich meinen Adapter, und dann setze ich einen Verweis auf meine Übereinstimmungen Knoten, um die Daten zu rekurrieren, das seltsame hier ist, dass es die PrepareData-Funktion eintritt, aber es tritt nie in den Listener, kein Erfolg kein Fehler.
bekomme ich einen staktrace meinem Adapter:
FATAL EXCEPTION: main
Process: com.esmad.pdm.friendlymanager, PID: 9887
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference
at com.esmad.pdm.friendlymanager.other.MatchGameAdapter.getItemCount(MatchGameAdapter.java:62)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:3447)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3264)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3798)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.support.constraint.ConstraintLayout.onLayout(ConstraintLayout.java:1197)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.support.v7.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:437)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1791)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1635)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1544)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at com.android.internal.policy.DecorView.onLayout(DecorView.java:736)
at android.view.View.layout(View.java:19393)
at android.view.ViewGroup.layout(ViewGroup.java:6022)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2480)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2199)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1385)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6722)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:886)
at android.view.Choreographer.doCallbacks(Choreographer.java:698)
at android.view.Choreographer.doFrame(Choreographer.java:633)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:872)
at android.os.Handler.handleCallback(Handler.java:769)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6540)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
dies ist mein Aktivitätscode:
public class AllMatches extends AppCompatActivity implements MatchGameAdapter.OnItemClickListener {
MatchGameAdapter matchGameAdapter;
RecyclerView recyclerView;
ArrayList<MatchViewModel> matches;
FirebaseDatabase database;
HashMap<String, String> matchesKeys;
String eventId;
String eventName;
DatabaseReference myRef;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_all_matches);
Intent i = getIntent();
Bundle extras = i.getExtras();
database = FirebaseDatabase.getInstance();
if(extras.containsKey("eventId")){
eventId = extras.getString("eventId");
}
if(extras.containsKey("matches")) {
matchesKeys = (HashMap<String, String>) i.getSerializableExtra("matches");
}
if(extras.containsKey("eventName")) {
eventName = extras.getString("eventName");
}
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
recyclerView = (RecyclerView)findViewById(R.id.rv);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(linearLayoutManager);
matchGameAdapter = new MatchGameAdapter(getApplicationContext(), matches,AllMatches.this);
recyclerView.setAdapter(matchGameAdapter);
prepareData();
}
private void prepareData() {
Log.d("hello","hello");
DatabaseReference myRef = database.getReference("Matches");
myRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
Log.d("hello","hello2");
Match match = snapshot.getValue(Match.class);
MatchViewModel matchViewModel = new MatchViewModel(match.getId(),eventId,eventName,match.getGameEnded(),snapshot.child("date").child("day").getValue().toString(), snapshot.child("date").child("month").getValue().toString(),snapshot.child("date").child("year").getValue().toString(),snapshot.child("date").child("hours").getValue().toString(),snapshot.child("date").child("minutes").getValue().toString());
Iterator it = matchesKeys.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry) it.next();
it.remove(); // avoids a ConcurrentModificationException
if (match.getId().equals(pair.getValue())) {
matches.add(matchViewModel);
}
}
}
matchGameAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.d("failed", "here");
}
});
}
@Override
public void onRowClick(String eventId, HashMap<String, Boolean> matches) {
}
}
und mein Adapter:
import java.util.ArrayList;
import java.util.HashMap;
public class MatchGameAdapter extends RecyclerView.Adapter<MatchGameAdapter.ViewHolder> {
private OnItemClickListener listener;
public interface OnItemClickListener {
void onRowClick(String eventId, HashMap<String, Boolean> matches);
}
private ArrayList<MatchViewModel> matches;
private Context context;
private View cv;
public MatchGameAdapter(Context context, ArrayList<MatchViewModel> matches, OnItemClickListener listener) {
this.matches = matches;
this.context = context;
this.listener = listener;
}
@Override
public MatchGameAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.eventgame, viewGroup, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(final MatchGameAdapter.ViewHolder viewHolder, final int i) {
viewHolder.name.setText(matches.get(i).getEventName() + " " + i + "ª Semana");
viewHolder.city.setText(matches.get(i).getDay() + "/" + matches.get(i).getMonth() + "/" + matches.get(i).getYear() + " " + matches.get(i).getHour() + ":" + matches.get(i).getMinute());
viewHolder.date.setText(matches.get(i).getHasEnded().toString());
viewHolder.field.setImageResource(R.drawable.match);
/*cv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(listener != null){
listener.onRowClick(events.get(i).getEventId(),events.get(i).getMatches());
}
}
});*/
}
@Override
public int getItemCount() {
return matches.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private ImageView field;
private TextView city;
private TextView date;
private TextView name;
public ViewHolder(View view) {
super(view);
cv = view;
name = (TextView)view.findViewById(R.id.eventName);
field = (ImageView)view.findViewById(R.id.field);
city = (TextView)view.findViewById(R.id.city);
date = (TextView)view.findViewById(R.id.date);
}
}
}