如何动态设置gridview的宽度

protected int widestData;
protected void GridView1_RowDataBound(object sender, 
    GridViewRowEventArgs e)
{
    System.Data.DataRowView drv;
    drv = (System.Data.DataRowView)e.Row.DataItem;
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
      if (drv != null)
      {
        String catName = drv[1].ToString();
        Response.Write(catName + "/");
        
        int catNameLen = catName.Length;
        if (catNameLen > widestData)
        {
          widestData = catNameLen;
          GridView1.Columns[2].ItemStyle.Width =
            widestData * 30;
          GridView1.Columns[2].ItemStyle.Wrap = false;
        }
        
      }
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    widestData = 0;
}