分页功能实现

private void GridViewBind()
        {
            string sql = "select A.ID,A.Style,A.WeekNum,A.DoubleClass, B.Class_Name,C.Course_Name,D.TeacherName   ";
            sql += " from tbl_JW_CourseBasic as A  ";
            sql += " left outer join tbl_SS_ClassManagement as B on A.ClassID=B.PK_Class_Num  ";
            sql += " left outer join tbl_SS_Curriculum as C on A.CoureseID=C.PK_Course_Num   ";
            sql += " left outer join tbl_RS_Teacher as D on A.TeacherID=D.PK_TeacherID ";
            DataSet ds = Common.Query(sql);
            int curPage = Convert.ToInt32(this.lblNoPage.Text.Trim());
            PagedDataSource ps = new PagedDataSource();
            string totalBar = ds.Tables[0].Rows.Count.ToString().Trim();
            this.lblTotalBar.Text = totalBar;
            ps.DataSource = ds.Tables[0].DefaultView;
            ps.AllowPaging = true;
            ps.PageSize = Convert.ToInt32(this.ddlBarPage.SelectedValue.ToString().Trim());
            this.lkbPrevious.Enabled = true;
            this.lkbNext.Enabled = true;
            this.lkbHome.Enabled = true;
            this.lkbLast.Enabled = true;
            ps.CurrentPageIndex = curPage - 1;
            int nobar = curPage * ps.PageSize;
            this.lblNoBar.Text = nobar.ToString().Trim();
            if (curPage == 1)
            {
                this.lkbPrevious.Enabled = false;
                this.lkbHome.Enabled = false;
            }
            if (curPage == ps.PageCount)
            {
                this.lkbNext.Enabled = false;