ViewPager中View的复用

代码例如以下：

public class MyViewPagerAdapter extends PagerAdapter {

    //显示的数据
    private List<DataBean> datas = null;

    private LinkedList<View> mViewCache = null;

    private Context mContext ;

    private LayoutInflater mLayoutInflater = null;


    public MyViewPagerAdapter(List<DataBean> datas, Context context) {
        super();
        this.datas = datas;
        this.mContext = context ;
        this.mLayoutInflater = LayoutInflater.from(mContext) ;
        this.mViewCache = new LinkedList<>();
    }

    @Override
    public int getCount() {
        Log.e("test","getCount ");
        return this.datas.size();
    }

    @Override
    public int getItemPosition(Object object) {
        Log.e("test","getItemPosition ");
        return super.getItemPosition(object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Log.e("test","instantiateItem " + position);
        ViewHolder viewHolder = null;
        View convertView = null;
        if(mViewCache.size() == 0){
            convertView = this.mLayoutInflater.inflate(R.layout.viewadapter_item_layout ,
                    null ,false);
            TextView textView = (TextView)convertView.findViewById(R.id.view_pager_item_textview);
            viewHolder = new ViewHolder();
            viewHolder.textView = textView;
            convertView.setTag(viewHolder);
        }else {
            convertView = mViewCache.removeFirst();
            viewHolder = (ViewHolder)convertView.getTag();
        }

        viewHolder.textView.setText(datas.get(position).title);
        viewHolder.textView.setTextColor(Color.YELLOW);
        viewHolder.textView.setBackgroundColor(Color.GRAY);

        container.addView(convertView ,ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT );

        return convertView;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        Log.e("test","destroyItem " + position);
        View contentView = (View) object;
        container.removeView(contentView);
        this.mViewCache.add(contentView);
    }

    @Override
    public boolean isViewFromObject(View view, Object o) {
        Log.e("test","isViewFromObject ");
        return view == o;
    }

    public final class ViewHolder{
        public TextView textView ;
    }
}