gridView中得部分性能优化 1 利用ViewHolder优化

public class MarkerItemAdapter extends BaseAdapter
{
    private Context mContext = null;
    private List<MarkerItem> mMarkerData = null;

    public MarkerItemAdapter(Context context, List<MarkerItem> markerItems)
    {
        mContext = context;
        mMarkerData = markerItems;
    }

    public void setMarkerData(List<MarkerItem> markerItems)
    {
        mMarkerData = markerItems;
    }

    @Override
    public int getCount()
    {
        int count = 0;
        if (null != mMarkerData)
        {
            count = mMarkerData.size();
        }
        return count;
    }

    @Override
    public MarkerItem getItem(int position)
    {
        MarkerItem item = null;

        if (null != mMarkerData)
        {
            item = mMarkerData.get(position);
        }

        return item;
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        ViewHolder viewHolder = null;
        if (null == convertView)
        {
            viewHolder = new ViewHolder();
            LayoutInflater mInflater = LayoutInflater.from(mContext);
            convertView = mInflater.inflate(R.layout.item_marker_item, null);

            viewHolder.name = (TextView) convertView.findViewById(R.id.name);
            viewHolder.description = (TextView) convertView
                    .findViewById(R.id.description);
            viewHolder.createTime = (TextView) convertView
                    .findViewById(R.id.createTime);

            convertView.setTag(viewHolder);
        }
        else
        {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        // set item values to the viewHolder:

        MarkerItem markerItem = getItem(position);
        if (null != markerItem)
        {
            viewHolder.name.setText(markerItem.getName());
            viewHolder.description.setText(markerItem.getDescription());
            viewHolder.createTime.setText(markerItem.getCreateDate());
        }

        return convertView;
    }

    private static class ViewHolder
    {
        TextView name;
        TextView description;
        TextView createTime;
    }

}

//ListView 中得优化
public class MarkerItemAdapter extends BaseAdapter
{
    private Context mContext = null;
    private List<MarkerItem> mMarkerData = null;

    public MarkerItemAdapter(Context context, List<MarkerItem> markerItems)
    {
        mContext = context;
        mMarkerData = markerItems;
    }

    public void setMarkerData(List<MarkerItem> markerItems)
    {
        mMarkerData = markerItems;
    }

    @Override
    public int getCount()
    {
        int count = 0;
        if (null != mMarkerData)
        {
            count = mMarkerData.size();
        }
        return count;
    }

    @Override
    public MarkerItem getItem(int position)
    {
        MarkerItem item = null;

        if (null != mMarkerData)
        {
            item = mMarkerData.get(position);
        }

        return item;
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        ViewHolder viewHolder = null;
        if (null == convertView)
        {
            viewHolder = new ViewHolder();
            LayoutInflater mInflater = LayoutInflater.from(mContext);
            convertView = mInflater.inflate(R.layout.item_marker_item, null);

            viewHolder.name = (TextView) convertView.findViewById(R.id.name);
            viewHolder.description = (TextView) convertView
                    .findViewById(R.id.description);
            viewHolder.createTime = (TextView) convertView
                    .findViewById(R.id.createTime);

            convertView.setTag(viewHolder);
        }
        else
        {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        // set item values to the viewHolder:

        MarkerItem markerItem = getItem(position);
        if (null != markerItem)
        {
            viewHolder.name.setText(markerItem.getName());
            viewHolder.description.setText(markerItem.getDescription());
            viewHolder.createTime.setText(markerItem.getCreateDate());
        }

        return convertView;
    }

    private static class ViewHolder
    {
        TextView name;
        TextView description;
        TextView createTime;
    }

}