GRIDVIEW行中显示提示信息

 protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {

            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                if (e.Row.Cells[0].Text.Trim() == "1")
                { e.Row.Cells[0].Text = "1-2节"; }
                if (e.Row.Cells[0].Text.Trim() == "2")
                { e.Row.Cells[0].Text = "3-4节"; }
                if (e.Row.Cells[0].Text.Trim() == "3")
                { e.Row.Cells[0].Text = "5-6节"; }
                if (e.Row.Cells[0].Text.Trim() == "4")
                { e.Row.Cells[0].Text = "7-8节"; }
                for (int i = 1; i <= 7; i++)
                {
                    string coursename = e.Row.Cells[i].Text.Trim();
                    if (coursename != null || coursename != "&nbsp;")
                    {
                        DataTable dt = (new sql()).getdetails(coursename);
                        if (dt.DefaultView.Count > 0)
                        {
                            DataRow dr = dt.Rows[0];
                            string str = "课程名称:" + dr["coursename"];
                            str = str + "\n任课老师:" + dr["teaname"];
                            str = str + "\n开课时间:" + dr["begintime"];
                            str = str + "\n开课地点:" + dr["beginplace"];
                            str = str + "\n课程学分:" + dr["tcount"];
                            str = str + "\n考试类型:" + dr["checkstyle"];
                            str = str + "\n课程类型:" + dr["coursequatity"];
                            str = str + "\n课程学时:" + dr["xueshi"];
                            e.Row.Cells[i].ToolTip = str;
                        }
                    }
                }