Android BaseAdapter应用详解

类概述
BaseAdapter主要用于ListView(实现指定的ListAdapter接口)、Spinner(实现指定的SpinnerAdapter接口)以及GridView的共同实现一个公共基类适配器。
假设我们实现一个ArrayListAdapter，
public abstract class ArrayListAdapter<T> extends BaseAdapter{
        
        protected ArrayList<T> mList;
        protected Activity mContext;
        protected ListView mListView;
        
        public ArrayListAdapter(Activity context){
                this.mContext = context;
        }

        @Override
        //设置像layout中填充的条目数量
        public int getCount() {
                if(mList != null)
                        return mList.size();
                else
                        return 0;
        }

        @Override
        public Object getItem(int position) {
                return mList == null ? null : mList.get(position);
        }

        @Override
        public long getItemId(int position) {
                return position;
        }

        @Override
    /**
     * @param position      position就是位置从0开始
     * @param convertView   convertView是Spinner,ListView中每一项要显示的view
     * @param parent        parent就是父窗体了，也就是Spinner,ListView,GridView了
     * @return              通常return 的view也就是convertView
     * 绘制的内容均在此实现
     */
        abstract public View getView(int position, View convertView, ViewGroup parent);
        
        public void setList(ArrayList<T> list){
                this.mList = list;
                notifyDataSetChanged();
        }
        
        public ArrayList<T> getList(){
                return mList;
        }
        
        public void setList(T[] list){
                ArrayList<T> arrayList = new ArrayList<T>(list.length);    
                for (T t : list) {    
                        arrayList.add(t);    
                }    
                setList(arrayList);
        }
        
        public ListView getListView(){
                return mListView;
        }
        
        public void setListView(ListView listView){
                mListView = listView;
        }

}