Gridview自动排序功能的实现

注意两点：
1.要将gridview的allowsorting属性置为true，同时设置onsorting事件

2.在onsorting事件中对排序的列设定sortexpression属性

        protected void page_load(object sender, eventargs e)
        {
            if (!page.ispostback)
            {
                if (session["admin"] != "admin")
                {
                    //如果会话过期，则应该重新登录
                    this.response.write(" <script language=javascript>alert('你无权访问该页面，请与管理员联系！');window.location.href='../userlogin.aspx';</script> ");
                }

                viewstate["sortexpression"] = "isdistribution";
                viewstate["sort"] = " asc";

            }
            //绑定信息
            bindnodeinfo();
        }

        public void bindnodeinfo()
        {
            nodelogic log = new nodelogic();
            dataset myset = log.getnodeinfo();     //获取数据源
            dataview myview = myset.tables[0].defaultview;
            myview.sort = viewstate["sortexpression"].tostring() +" "+ viewstate["sort"].tostring();
            this.nodegridview.datasource = myview;
            nodegridview.datakeynames = new string[] { "node_id" };               //设置主键字段
            nodegridview.databind();                                                  //绑定gridview控件 
        }

        protected void nodegridview_pageindexchanging(object sender, gridviewpageeventargs e)
        {
            this.nodegridview.pageindex = e.newpageindex;
            bindnodeinfo();
        }

        protected void nodegridview_rowdatabound(object sender, gridviewroweventargs e)
        {
            // 自动给第一列编号
            if (e.row.rowindex > -1)
            {
                e.row.cells[0].text = convert.tostring(e.row.rowindex + 1);
            }
        }

        protected void nodegridview_rowdeleting(object sender, gridviewdeleteeventargs e)
        {
            nodelogic log = new nodelogic();
            int id = int.parse(this.nodegridview.datakeys[e.rowindex].values[0].tostring());
            if (log.deletenodeinfo(id))
            {
                this.page.clientscript.registerstartupscript(this.gettype(), "", "alert('删除成功！');", true);
            }
            else
                this.page.clientscript.registerstartupscript(this.gettype(), "", "alert('删除失败！');", true);
            //重新更新数据显示
            bindnodeinfo();
        }

        protected void nodemgridview_rowediting(object sender, gridviewediteventargs e)
        {

        }

        protected void addnode_click(object sender, eventargs e)
        {
            response.redirect("addnode.aspx");
        }

        protected void nodegridview_sorting(object sender, gridviewsorteventargs e)
        {

            if (viewstate["sortexpression"] != null)
            {
                if (viewstate["sort"].tostring() == "asc")
                {
                    viewstate["sort"] = "desc";
                }
                else
                {
                    viewstate["sort"] = "asc";

                }
            }
            bindnodeinfo();
        }