/**

    * @see android.widget.ListAdapter# getView(int, View, ViewGroup)

    */

   public View getView( int position, View convertView, ViewGroup parent) {

       if (!mDataValid) {

           throw new IllegalStateException( "this should only be called when the cursor is valid");

       }

       if (!mCursor.moveToPosition(position)) {

           throw new IllegalStateException( "couldn't move cursor to position " + position);

       }

       View v;

       if (convertView == null) {

           v = newView( mContext, mCursor, parent);

       } else {

           v = convertView;

       }

       bindView(v, mContext, mCursor);

       return v;

   }  

public abstract View newView (Context context, Cursor cursor, ViewGroup parent);  

public abstract void bindView(View view, Context context, Cursor cursor);  

• newView ( )：并不是每次都被调用的，它只在实例化的时候调用,数据增加的时候也会调用,但是在重绘(比如修改条目里的TextView的内容)的时候不会被调用

• bindView ( )：从代码中可以看出在绘制Item之前一定会调用bindView方法它在重绘的时候也同样被调用

继承CursorAdapter的示例部分代码:

@Override

     public View newView(Context context, Cursor cursor, ViewGroup parent) {  

           ViewHolder viewHolder= new ViewHolder();

           LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE );

           View view=inflater.inflate(R.layout.item_contacts ,parent,false);  

           viewHolder. tv_name=(TextView) view.findViewById(R.id.tv_showusername );

           viewHolder. tv_phonenumber=(TextView) view.findViewById(R.id.tv_showusernumber );

           view.setTag(viewHolder);

           Log. i("cursor" ,"newView=" +view);

            return view;

     }  

     @Override

     public void bindView(View view, Context context, Cursor cursor) {

           Log. i("cursor" ,"bindView=" +view);

           ViewHolder viewHolder=(ViewHolder) view.getTag();

       //从数据库中查询姓名字段

           String name=cursor.getString(cursor.getColumnIndex(PersonInfo.NAME));

       //从数据库中查询电话字段

           String phoneNumber=cursor.getString(cursor.getColumnIndex(PersonInfo.PHONENUMBER));  

           viewHolder. tv_name.setText(name);

           viewHolder. tv_phonenumber.setText(phoneNumber);

     }  

缺点：

1. 直接把Cursor暴露在UI层，写了很多 cursor.getString(cursor.getColumnIndex("scheme"))类似的代码.直接把Cursor暴露在ui层是很不好的示范，Cursor是非常底层的数据模型，不应该暴露在ui层。
2. SQLite 加载超过1M数据速度会变得很慢.一旦数据量大了整个UI的速度立刻降了下来。
3. RecyclerView 并不支持 CursorAdapter

总之，CursorAdapter这种方式并不是很好的设计典范。