关于GridView item动态宽度的问题

最近在android项目中，遇到需要动态设置GridView列数的问题，实现如下：

首先大体估算一下item宽度（这里估计宽度100，然后计算满屏能显示几个item）：

  GridView hotGrid = (GridView) findViewById(R.id.hot_word_grid);
        int colnum = ZETTool.getScreenWith(HomeSearchActivity.this) / 100;
        hotGrid.setNumColumns(colnum);

在Adapter  getView方法中：

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

        TextView wordTV;
        if (convertView == null){
            convertView = LayoutInflater.from(context).inflate(R.layout.hot_word_item,null);
            wordTV = (TextView)convertView.findViewById(R.id.grid_hot_word_tv);

            convertView.setTag(wordTV);
        }else {
            wordTV = (TextView)convertView.getTag();
        }

        HotWordsModel.ContractRootModel.BusContModel.KeywordListModel model = dataList.get(position);
        wordTV.setText(model.getContent());

        // 根据列数计算项目宽度，以使总宽度尽量填充屏幕
        int itemWidth = (ZETTool.getScreenWith((Activity) context) -  colnum * 10)  / colnum;
        AbsListView.LayoutParams param = new AbsListView.LayoutParams(
                itemWidth,
                AbsListView.LayoutParams.WRAP_CONTENT);
        convertView.setLayoutParams(param);

        return convertView;
    }

附上效果图