下拉框指定页面条数

1.. 前台
 <PagerTemplate>   
<asp:DropDownList ID="ddlpage" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlpage_SelectedIndexChanged">
                                                    <asp:ListItem>12</asp:ListItem>
                                                    <asp:ListItem>20</asp:ListItem>
                                                    <asp:ListItem>30</asp:ListItem>
                                                    <asp:ListItem>40</asp:ListItem>
                                                    <asp:ListItem>50</asp:ListItem>
                                                </asp:DropDownList>
                                </PagerTemplate>
2.. 后台
 protected void ddlpage_SelectedIndexChanged(object sender, EventArgs e)
        {
            DropDownList dllpage= (DropDownList)Grv_Com.BottomPagerRow.Cells[0].FindControl("ddlpage");
            ViewState["page"]= dllpage.SelectedValue.ToString();
            Grv_Com.PageSize = Convert.ToInt32(dllpage.SelectedValue.ToString ());
            GetDataToGridView(SetSql(Drp_Department.GetBMBH));
            ((DropDownList)Grv_Com.BottomPagerRow.Cells[0].FindControl("ddlpage")).SelectedValue = Grv_Com.PageSize.ToString ();

        }

3.. 后台
GetDataToGridView 数据绑定函数 添加

 Grv_Com.DataBind(); //下面
 数据为空时不要执行下面的代码
   if(Grv_Com.Rows.Count>0){
 ((DropDownList)Grv_Com.BottomPagerRow.Cells[0].FindControl("ddlpage")).SelectedValue = Grv_Com.PageSize.ToString();}