Recycling issues in ArrayAdapter using ImageFetche

问题:

I'm currently using (or at least attempting to use) Droidparts ImageFetcher in my application. There is sample code available showing how it works with CursorAdapter but I haven't been able to understand all of it and replicate it with my ArrayAdapter. I think I understand how the InjectDependency stuff works, but if that could either be further explained or not included in the answer, I'd be grateful.

Anyways, my question is, how do I stop my imageViews from loading with the wrong images once they have been recycled? I've tried attaching an ImageHolder as a tag to the view but it hasn't worked and I can't see the logic behind it...

Here's my code:

@Override
public View getView( int position, View view, ViewGroup parent )
{
    if( view == null )
    {
        LayoutInflater inflater = ( LayoutInflater ) m_context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
        view = inflater.inflate( m_resourceId, parent, false );
    }

    TextView titleView = ( TextView ) view.findViewById( R.id.title );
    if( titleView != null ) titleView.setText( m_values.get( position ).title );

    ImageView imageView = ( ImageView ) view.findViewById( R.id.image );
    if( imageView != null )
    {
        imageView.setImageDrawable( null );

        ViewHolder holder = new ViewHolder();
        holder.imageView = imageView;

        m_imageFetcher = new ImageFetcher( m_context );
        m_imageFetcher.attachImage(m_values.get( position ).imageUrl, holder.imageView, null, 10, null);

        view.setTag(holder);
    }

    return view;
}

Any pointer or example would be greatly appreciated, thanks!

回答1:

I'd recommend you to extends org.droidparts.adapter.widget.ArrayAdapter that already contains an instance of LayoutInflater.

If you do so, here's the code, the logic should be easy to follow:

public class MyArrayAdapter extends ArrayAdapter<MyModel> {

    private final ImageFetcher imageFetcher;

    public MyArrayAdapter(Context ctx, List<MyModel> list) {
        super(ctx, list);
        imageFetcher = new ImageFetcher(ctx);
    }

    @Override
    public View getView(int position, View view, ViewGroup parent) {
        if (view == null) {
            view = layoutInflater.inflate(m_resourceId, null);
            ViewHolder holder = new ViewHolder();
            holder.titleView = ViewUtils.findViewById(view, R.id.title);
            holder.iconView = ViewUtils.findViewById(view, R.id.image);
            view.setTag(holder);
        }
        ViewHolder holder = (ViewHolder) view.getTag();
        holder.iconView.setImageDrawable(null);
        MyModel item = getItem(position);
        holder.titleView.setText(item.title);
        imageFetcher.attachImage(item.iconUrl, holder.iconView);
        return view;
    }

    private static class ViewHolder {
        TextView titleView;
        ImageView iconView;
    }

}

Also check out it's setContent(...) method as an alternative to providing object list in the constructor. And of course make sure that you've declared <uses-permission android:name="android.permission.INTERNET" />.