DataGrid分页

DataGrid分页通用
void initpage()
        {
            string topsql = string.Format(@"select count(a.ProductCode) from Production as a,MyCompanyWeb as b,Pictures as c 
                                                where a.UserSID=b.UserSID and a.ProductCode=c.ProductCode and OneFunSID={0} and State=1",onefunid);
                
            object o=this.Db.CreateStatement(topsql).GetScalar();
            int rowCount=0;
            if(o==null)
            {
                CurrentPageIndex=0;
                return;
            }

            rowCount=Convert.ToInt32(o.ToString ());
            if(rowCount%PageSize==0)
            {
                PageCount=rowCount/PageSize;
            }
            else
            {
                PageCount=rowCount/PageSize+1;
            }

            lblCount.Text=PageCount.ToString();
            if(PageCount>0)
            {
                CurrentPageIndex=1;
                GridBind();
            }
            else
            {
                DataList1.DataSource = new DataTable ();
                DataList1.DataBind ();
            }
            SetLinkLutton();
        }

        void GridBind()
        {
            string sqlstr=string.Empty;
            if(CurrentPageIndex==1)
            {
                sqlstr=String.Format (@"select top {0} a.ProductSID,a.ProductCode,ProductName,a.CreateTime,Quality,KeyWords,Amount,b.Company,c.ImageUrl1 
                                                from Production as a,MyCompanyWeb as b,Pictures as c 
                                                where a.UserSID=b.UserSID and a.ProductCode=c.ProductCode and OneFunSID={1} and State=1 order by a.BallotNew desc,a.CreateTime desc",
                                                this.PageSize,onefunid);
                    
            }
            else
            {
                int cindex = (CurrentPageIndex-1)*PageSize;
                sqlstr=String.Format (@"select top {0} a.ProductSID,a.ProductCode,ProductName,a.CreateTime,Quality,KeyWords,Amount,b.Company,c.ImageUrl1 
                                                from Production as a,MyCompanyWeb as b,Pictures as c 
                                                where a.ProductSID not in (select top {1} a.ProductSID from Production as a,MyCompanyWeb as b,Pictures as c
                                                where a.UserSID=b.UserSID and a.ProductCode=c.ProductCode and a.OneFunSID={2} and State=1 order by a.BallotNew desc,a.CreateTime desc) 
                                                and a.UserSID=b.UserSID and a.ProductCode=c.ProductCode and OneFunSID={2} and State=1 order by a.BallotNew desc,a.CreateTime desc",
                                                this.PageSize.ToString(),cindex.ToString(),onefunid);
            }
            

            DataTable tb=Db.CreateStatement (sqlstr).GetDataTable ();
            if(tb!=null && tb.Rows.Count>0)
            {
                DataList1.DataSource =tb;
                DataList1.DataBind ();
            }
            else
            {
                DataList1.DataSource = new DataTable ();
                DataList1.DataBind ();
            }
            SetLinkLutton();
            lblCur.Text =CurrentPageIndex.ToString();

        }
        
        public int CurrentPageIndex
        {
            get
            {
                object o= ViewState["CurrentPageIndex"];
                return o==null?0:Convert.ToInt32(o);
            }
            set
            {
                ViewState["CurrentPageIndex"]=value;
            }
        }

        public int PageCount
        {
            get
            {
                object o= ViewState["PageCount"];
                return o==null?0:Convert.ToInt32(o);
            }
            set
            {
                ViewState["PageCount"]=value;
            }
        }
        public string sqlWhere
        {
            get
            {
                return (string)ViewState["SqlWhere"];
            }
            set
            {
                ViewState["SqlWhere"]=value;
            }
        }

        void SetLinkLutton()
        {
            if(CurrentPageIndex==0)
            {
                lbtFirst.Enabled  =false;
                lbtPre.Enabled =false;
                lbtNext.Enabled =false;
                lbtLast.Enabled =false;
            }
            else if(CurrentPageIndex==1)
            {
            
                lbtFirst.Enabled =false;
                lbtPre.Enabled =false;
                lbtNext.Enabled =true;
                lbtLast.Enabled =true;
                if(CurrentPageIndex==PageCount)
                {
                    lbtNext.Enabled =false;
                    lbtLast.Enabled =false;
                }
            }
            else if(CurrentPageIndex==PageCount)
            {
            
                lbtFirst.Enabled =true;
                lbtPre.Enabled =true;
                lbtNext.Enabled =false;
                lbtLast.Enabled =false;
            }
            else
            {
                lbtFirst.Enabled =true;
                lbtPre.Enabled =true;
                lbtNext.Enabled =true;
                lbtLast.Enabled =true;
            }
        }

        private void lbtLast_Click(object sender, System.EventArgs e)
        {    
            this.CurrentPageIndex=PageCount;
            GridBind();
        }

        private void lbtNext_Click(object sender, System.EventArgs e)
        {
            if(CurrentPageIndex<PageCount)
            {
                this.CurrentPageIndex=CurrentPageIndex+1;
                GridBind();
            }
        }

        private void lbtPre_Click(object sender, System.EventArgs e)
        {
            if(CurrentPageIndex>1)
            {
                this.CurrentPageIndex=CurrentPageIndex-1;
                GridBind();
            }
        }

        private void lbtFirst_Click(object sender, System.EventArgs e)
        {
            this.CurrentPageIndex=1;
            GridBind();
        }