Ich habe einen Viewholder mit mehreren Viewtypen.RecyclerView onBindViewHolder wird nur aufgerufen, wenn sich getItemViewType ändert
Beim Scrollen wird onBindViewHolder
nur aufgerufen, wenn getItemViewType
den Wert ändert. Dies führt dazu, dass meine Listenelemente nicht korrekt aktualisiert werden.
Ist das ein Fehler? Oder ich mache hier etwas falsch. Dies scheint sehr seltsames Verhalten von der neuen recyclerView
Klasse.
Hier ist mein Adapter:
package se.davison.smartrecycleradapter;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.util.SparseIntArray;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
/**
* Created by richard on 10/11/14.
*/
public class SectionAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final String TAG = SectionAdapter.class.getSimpleName();
private final LayoutInflater inflater;
private final int sectionLayoutId;
private SparseIntArray positionSection;
private LinkedHashMap<AdapterItem, List<AdapterItem>> items = new LinkedHashMap<AdapterItem, List<AdapterItem>>();
private List<Class<? extends AdapterItem>> itemTypes = new ArrayList<Class<? extends AdapterItem>>(20);
public SectionAdapter(Context context, int sectionLayoutId, LinkedHashMap<AdapterItem, List<AdapterItem>> items) {
this.inflater = LayoutInflater.from(context);
this.sectionLayoutId = sectionLayoutId;
this.items = items;
initList(items);
}
public SectionAdapter(Context context, int sectionLayoutId) {
this.inflater = LayoutInflater.from(context);
this.sectionLayoutId = sectionLayoutId;
this.items = new LinkedHashMap<AdapterItem, List<AdapterItem>>();
initList(items);
}
@Override
public int getItemViewType(int position) {
AdapterItem item = getItem(position);
Log.d(TAG, position + ": class " + item.getClass());
return itemTypes.indexOf(item.getClass());
}
@Override
public int getItemCount() {
int count = 0;
if (items == null) {
return 0;
}
for (AdapterItem key : items.keySet()) {
count++;
List<AdapterItem> childItems = items.get(key);
if (childItems != null) {
count += childItems.size();
}
}
return count;
}
private void initList(HashMap<AdapterItem, List<AdapterItem>> items) {
positionSection = new SparseIntArray(items.size());
int count = 0;
int sectionIndex = -1;
for (AdapterItem key : items.keySet()) {
Class headerClass = key.getClass();
if (!itemTypes.contains(headerClass)) {
itemTypes.add(headerClass);
}
List<AdapterItem> childItems = items.get(key);
sectionIndex = count;
if (childItems != null) {
for (AdapterItem item : childItems) {
Class clazz = item.getClass();
if (!itemTypes.contains(clazz)) {
itemTypes.add(clazz);
}
positionSection.put(count, sectionIndex);
count++;
}
}
count++;
}
setHasStableIds(true);
}
private AdapterItem getItem(int position) {
int totalChildCount = 0;
int separatorCount = 0;
for (AdapterItem key : items.keySet()) {
if (position == 0 || position == totalChildCount + separatorCount) {
return key;
}
separatorCount++;
List<AdapterItem> list = items.get(key);
int couldCount = countList(list);
if (position < totalChildCount + separatorCount + couldCount) {
return list.get(position - (totalChildCount + separatorCount));
}
totalChildCount += couldCount;
}
return null;
}
public void setItems(LinkedHashMap<AdapterItem, List<AdapterItem>> items) {
this.items = items;
notifyDataSetChanged();
}
public void setItemsAtHeader(int id, List<AdapterItem> items) {
AdapterItem header = null;
for (AdapterItem key : this.items.keySet()) {
if (key.headerId() == id) {
header = key;
break;
}
}
if (header == null) {
throw new IllegalArgumentException(String.format("No header with id %s is found", id));
}
setItemsAtHeader(header, items);
}
private void setItemsAtHeader(AdapterItem header, List<AdapterItem> items) {
this.items.put(header, items);
}
private int countList(List<?> list) {
return list == null ? 0 : list.size();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
AdapterItem firstItem = getFirstItemWithClass(itemTypes.get(viewType));
return firstItem.onCreateViewHolder(inflater, viewGroup);
}
private AdapterItem getFirstItemWithClass(Class<? extends AdapterItem> clazz) {
for (AdapterItem key : items.keySet()) {
if (key.getClass() == clazz) {
return key;
}
List<AdapterItem> childItems = items.get(key);
if (childItems != null) {
for (AdapterItem item : childItems) {
if (item.getClass() == clazz) {
return item;
}
}
}
}
throw new IllegalStateException("Something is wrong, you dont have any items with that class in your list");
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
AdapterItem item = getItem(position);
Log.d(TAG, "ITEM = " + item.getClass().getSimpleName());
Log.d(TAG, "POS = " + position);
if (item instanceof OneLineAdapterItem) {
Log.d(TAG, "TEXT = " + ((OneLineAdapterItem) item).getText());
}
item.onBindViewHolder(viewHolder, position);
}
}
Ich habe auch die Produkte wie so abstrahiert aus:
public abstract class AdapterItem<VH extends RecyclerView.ViewHolder> {
public boolean isHeader(){
return false;
}
public int headerId(){
return -1;
}
public abstract VH onCreateViewHolder(LayoutInflater inflater, ViewGroup parent);
public abstract void onBindViewHolder(VH viewHolder, int position);
}
Und für Abschnitte
public class SectionAdapterItem extends AdapterItem<SectionAdapterItem.ViewHolder> {
private String text;
private boolean dividerVisible = false;
public static class ViewHolder extends RecyclerView.ViewHolder{
TextView titel;
ImageView divider;
public ViewHolder(View itemView) {
super(itemView);
titel = (TextView) itemView.findViewById(android.R.id.title);
divider = (ImageView) itemView.findViewById(android.R.id.icon);
}
}
public void setDividerVisible(boolean dividerVisible) {
this.dividerVisible = dividerVisible;
}
public boolean isDividerVisible() {
return dividerVisible;
}
@Override
public boolean isHeader() {
return true;
}
@Override
public int headerId() {
return super.headerId();
}
public SectionAdapterItem(String text) {
this.text = text;
}
@Override
public ViewHolder onCreateViewHolder(LayoutInflater inflater, ViewGroup parent) {
return new ViewHolder(inflater.inflate(R.layout.top_header, parent, false));
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
viewHolder.titel.setText(text);
viewHolder.divider.setVisibility(dividerVisible?View.VISIBLE:View.GONE);
}
}
Es ist für die frist funktioniert gut sichtbare Zeilen, aber dann schlägt es fehl.
was meinst du mit onBind heißt nie? Was passiert stattdessen, es zeigt nichts? Scrollen stoppt? – yigit
@Yigit die ersten Elemente werden ordnungsgemäß angezeigt. Aber wenn ich mit dem Scrollen anfange, werden meine Artikel nur recycelt, so dass ihre Daten nicht aktualisiert werden, da onBind nicht für jede Zeile aufgerufen wird, während ich scrolle. Ich werde bald ein paar Screenshots hinzufügen! – Richard
für mich war das das Problem. http://stackoverflow.com/a/29162119/371749 – cV2