fix

    class HomeListAdapter extends SimpleCursorAdapter {

        public HomeListAdapter (Context context, int layout, Cursor c,
                String[] from, int[] to) {
            super(context, layout, c, from, to);
            mImageLoader = new ImageDownloader(mResources,((BitmapDrawable)mResources.getDrawable(R.drawable.default_row_pic)).getBitmap(), 1);
            this.context = context;
        }

        Context context = null;
        ImageDownloader mImageLoader = null;

        @Override
        public void setViewImage(ImageView v, String value) {
                    if(!value.equals("")){
                        mImageLoader.download(value, (ImageView)v);
                    }
                    else {
                        v.setImageResource(R.drawable.default_row_pic);
                    }
        }
    }

//using adapter

String[] from = new String[] {DBAdapter.KEY_CATEGORY_NAME, DBAdapter.KEY_URL_PIC, DBAdapter.KEY_INTRO, DBAdapter.KEY_TITLE};
int[] to = new int[] {R.id.cat, R.id.picture, R.id.intro, R.id.title};

new HomeListAdapter(this, R.layout.article_row, c, from, to)