我正在使用parse-server來開發使用RecyclerView顯示圖像項目的應用程序。當我每次上下滾動時,Android RecyclerView顯示項目發生變化
但問題是,每當我上下滾動時,視圖中顯示的項目都會發生變化。
我想知道我的代碼有什麼問題。
如果你看到下面的圖片,你可以找到物品正在改變它們的位置。
我試圖讓持有人圖像變成空,然後再次打電話給持有人。但它不起作用。我想這again.but我無法找到的情況
enter image description here enter image description here
原因RecyclerParseAdapter.java
public class MyTimelineAdapter extends RecyclerParseAdapter {
private interface OnQueryLoadListener<ParseObject> {
public void onLoading();
public void onLoaded(List<ParseObject> objects, Exception e);
}
private static ParseQueryAdapter.QueryFactory<ParseObject> queryFactory;
private static List<OnQueryLoadListener<ParseObject>> onQueryLoadListeners;
private static List<List<ParseObject>> objectPages;
private static ArrayList<ParseObject> items;
private static int currentPage;
private static RequestManager requestManager;
public MyTimelineAdapter(Context context, RequestManager requestManager) {
super(context);
this.requestManager = requestManager;
this.onQueryLoadListeners = new ArrayList<>();
this.currentPage = 0;
this.objectPages = new ArrayList<>();
this.items = new ArrayList<>();
this.queryFactory = new ParseQueryAdapter.QueryFactory<ParseObject>() {
@Override
public ParseQuery<ParseObject> create() {
ParseQuery<ParseObject> query = ParseQuery.getQuery("ImageClassName");
query.setCachePolicy(ParseQuery.CachePolicy.CACHE_THEN_NETWORK);
query.whereEqualTo("status", true);
query.orderByDescending("createdAt");
return query;
}
};
loadObjects(currentPage);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View timelineView;
timelineView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_timeline_item2, parent, false);
TimelineItemViewHolder timelineItemViewHolder = new TimelineItemViewHolder(timelineView);
return timelineItemViewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final ParseObject timelineOb = getItem(position);
FunctionPost functionPost = new FunctionPost(context);
functionPost.TimelineArtistPostAdapterBuilder(timelineOb, holder, requestManager);
//기능 추가
}
@Override
public int getItemCount() {
return items.size();
}
@Override
public ParseObject getItem(int position) {
return items.get(position);
}
@Override
public void loadObjects(final int page) {
final ParseQuery<ParseObject> query = this.queryFactory.create();
if (this.objectsPerPage > 0 && this.paginationEnabled) {
this.setPageOnQuery(page, query);
}
this.notifyOnLoadingListeners();
if (page >= objectPages.size()) {
objectPages.add(page, new ArrayList<ParseObject>());
}
query.findInBackground(new FindCallback<ParseObject>() {
@Override
public void done(List<ParseObject> foundObjects, ParseException e) {
if ((e != null) && ((e.getCode() == ParseException.CONNECTION_FAILED) || (e.getCode() != ParseException.CACHE_MISS))) {
hasNextPage = true;
} else if (foundObjects != null) {
// Only advance the page, this prevents second call back from CACHE_THEN_NETWORK to
// reset the page.
if (page >= currentPage) {
currentPage = page;
// since we set limit == objectsPerPage + 1
hasNextPage = (foundObjects.size() > objectsPerPage);
}
if (paginationEnabled && foundObjects.size() > objectsPerPage) {
// Remove the last object, fetched in order to tell us whether there was a "next page"
foundObjects.remove(objectsPerPage);
}
List<ParseObject> currentPage = objectPages.get(page);
currentPage.clear();
currentPage.addAll(foundObjects);
syncObjectsWithPages(items, objectPages);
// executes on the UI thread
notifyDataSetChanged();
}
notifyOnLoadedListeners(foundObjects, e);
}
});
}
public void loadNextPage() {
if (items.size() == 0) {
loadObjects(0);
} else {
loadObjects(currentPage + 1);
}
}
public void syncObjectsWithPages(ArrayList<ParseObject> items, List<List<ParseObject>> objectPages) {
items.clear();
for (List<ParseObject> pageOfObjects : objectPages) {
items.addAll(pageOfObjects);
}
}
protected void setPageOnQuery(int page, ParseQuery<ParseObject> query) {
query.setLimit(this.objectsPerPage + 1);
query.setSkip(page * this.objectsPerPage);
}
public void addOnQueryLoadListener(OnQueryLoadListener<ParseObject> listener) {
this.onQueryLoadListeners.add(listener);
}
public void removeOnQueryLoadListener(OnQueryLoadListener<ParseObject> listener) {
this.onQueryLoadListeners.remove(listener);
}
public void notifyOnLoadingListeners() {
for (OnQueryLoadListener<ParseObject> listener : this.onQueryLoadListeners) {
listener.onLoading();
}
}
public void notifyOnLoadedListeners(List<ParseObject> objects, Exception e) {
for (OnQueryLoadListener<ParseObject> listener : this.onQueryLoadListeners) {
listener.onLoaded(objects, e);
}
}
}
謝謝〜@布萊恩真的很有幫助.. – ssamkyu