Viewholder of recyclerview getting called for each item

Question

I have Recyclerview in my project which is having one ViewHolder. For this RecyclerView, i have many items to populate, but for the simplicity sake, i have added 100 items. But for these 100 items onCreateViewHolder is being called 100 items i.e. for each item it is being called, hence for each item view is getting infalted. If i will use all items(may be 1000 or 2000), i am getting OOM. SO how can i avoid this call of onCreateViewHolder for each item. Really need help!!

public static final int HEADER = Integer.MIN_VALUE;
public static final int FOOTER = Integer.MIN_VALUE + 1;
public static final int ADAPTER_OFFSET = 2;

@Override
    public int getItemViewType(int position) {
        if (position == 0 && useHeader()) {
            return HEADER;
        }

        if (useHeader() && position > getBasicItemCount() && useFooter())
            return FOOTER;
        else if (!useHeader() && position >= getBasicItemCount() && useFooter())
            return FOOTER;

        int basicItemType = getBasicItemType(position - (useHeader() ? 1 : 0));

        if (basicItemType >= Integer.MAX_VALUE - ADAPTER_OFFSET) {
            new IllegalStateException(
                    "");
        }

        return basicItemType + ADAPTER_OFFSET;
    }

@Override
    public int getBasicItemType(int position) {
        return position;
    }

@Blackbelt, Thanks man, but my adapter i can't post here. Sorry for that. But it is straight forward simple adapter. I don't know what i am doing wrong. Please if you can help withour seeing the adapter — Android Killer, Jun 25 '16 at 19:02
@Blackbelt no, i am returning View Type like footer, header. — Android Killer, Jun 25 '16 at 19:04
I would log how many different `basicItemType` do you have, in your getItemViewType — Blackbelt, Jun 25 '16 at 19:12
basicItemType returning position only. Please have a look. Edited the question. — Android Killer, Jun 25 '16 at 19:14
that's the mistake. Try returning `Math.max(TYPE_FOOTER, TYPE_HEADER) + 1` instead of `basicItemType + TYPE_ADAPTEE_OFFSET;` and check if it fixes your issue — Blackbelt, Jun 25 '16 at 19:16
@Blackbelt added the constants value as well in the question in the top. Still should i return Math.max(TYPE_FOOTER, TYPE_HEADER) + 1 ?? — Android Killer, Jun 25 '16 at 19:17
the constants are irrelevant. As last return instead of `basicItemType + TYPE_ADAPTEE_OFFSET;` do `return TYPE_ADAPTEE_OFFSET`; — Blackbelt, Jun 25 '16 at 19:19
@Blackbelt This has solved the problem mostly. Some edit i have to do. But what was the problem. If you can explain in any answer, so that i can undertsand the concept as well as i can accept the answer. — Android Killer, Jun 25 '16 at 19:36

score 4 · Accepted Answer · answered Jun 25 '16 at 19:46

getItemViewType changes the number of times onCreateViewHolder is called. The documentation states that it

Return the view type of the item at position for the purposes of view recycling.

it means that every time getItemViewType return a different value, Android thinks that you are dealing with a new different type, and you want a different view for it. Your implementation, is returning position. It means getItemCountdifferent views

Viewholder of recyclerview getting called for each item

1 Answers1