bad convertView type BaseAdapter of ListView

Question

I have a list view adapter that uses different types of view rows.

Most of the time it works fine. But when I remove an element from the list it crashes. It sends a convertView of the incorrect type to getView

public View getView(int position, View convertView, ViewGroup patent) ...  

But getItemViewType is returning the correct type.

public int getItemViewType(int position)

so I see something that looks like this

give me the type for position 1 -> returns correct type (say 1)

give me a view for position 1 with a content view for the wrong type (say type 2.)

Any ideas?

Answer 1

That's normal, if you get a View with different type in convertView, you would create a new View, and not reuse convertView.

Probably there are no reusable views with the given type.

Note: This answer is from 2011 and might no longer apply.

Answer 2

Try overiding getViewTypeCount()

@Override
public int getViewTypeCount() {
       return types;
}

Return the number of types of Views that will be created by getView(int, View, ViewGroup). Each type represents a set of views that can be converted in getView(int, View, ViewGroup).

Answer 3

When implemented right, the ListView guarantees that the view provided as the convertView is from the right Type

     /**
     * @return A view from the ScrapViews collection. These are unordered.
     */
    View getScrapView(int position) {
        if (mViewTypeCount == 1) {
            return retrieveFromScrap(mCurrentScrap, position);
        } else {
            int whichScrap = mAdapter.getItemViewType(position);
            if (whichScrap >= 0 && whichScrap < mScrapViews.length) {
                return retrieveFromScrap(mScrapViews[whichScrap], position);
            }
        }
        return null;
    }

You should override getViewTypeCount(), returning the number of view types you have and override getItemViewType(int position) returning the view type in the range from 0 to getViewTypeCount() - 1

Answer 4

I had the same issue and it resulted in crashes or unexpected behavior.
This how I fixed my issue:

getViewTypeCount() should return the number of different type of rows in the view

getItemViewType(...) should return the type of the item at position

getView(...) should set a enum type on view when inflated

@Override
public int getViewTypeCount() {
    return 2;
}

@Override
public int getItemViewType(int position) {
    return mlistItems.get(position).type.ordinal();
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ListItem item = mListems.get(position);

    if (convertView == null) {
        switch (item.type) {
            case Header:
                converview = // Inflate Header Row
                break;
            case Content:
                converview = // Inflate Content Row
                break;
        }
    }

    switch (item.type) {
            case Header:
                //Set header row content
                break;
            case Content:
                //Set content row content
                break;
    }

    return convertView;
}