一个GridView如何再次绑定呀

protected void GridViewBind(string condition)        {            string sql = "select *from teacher";            Common comn = new Common();            DataSet ds = comn.GetDataSet(sql);            #region 实现单击列标题排序要用到的代码            DataView myView = ds.Tables[0].DefaultView;            string sort = (string)ViewState["SortOrder"] + " " + (string)ViewState["OrderDire"];            myView.Sort = sort;            #endregion            GridView1.DataSource = ds.Tables[0].DefaultView;            GridView1.DataBind();                    }

protected void BtnConfirm1_Click(object sender, EventArgs e)        {            string sql = "select   * from  teacher  where 1=0 ";            string sqlCondition = string.Empty;            if (txtTeacherNum.Text.Trim() != "")             {                sqlCondition += "and   tid   like   '" + txtTeacherNum.Text.Trim() + "%'   ";             }            if (txtTeacherName.Text.Trim() != "")             {                sqlCondition += "and   tname   =   '%" + txtTeacherName.Text.ToString() + "%'   ";             }            if (txtSubject.Text.Trim() != "")             {                sqlCondition += "and  subject   =   '%" + txtSubject.Text.ToString() + "%'   ";             }            sql += sqlCondition;            Common comm = new Common();            comm.ExecuteNonQuery(sql);            GridView1.EditIndex = -1;                // 这里怎么绑定呀？                    }