GridView多层嵌套和折叠与展开(修改适合自己使用)

insus.net近段时间应朋友的要求，写一个gridview多层嵌套和折叠与展开。这个功能的gridview多层嵌套没有问题，因为已经做了无限次数，但是折叠与展开的功能，却花上不少时间(网上找资料)，虽找到资料可参考，还是了解明它，并修改适合自己程序使用。效果如下：

站点中多个页面使用，因此insus.net把它写在一个用户自定义控件ascx上。

insusmenu.ascx

<%@ control language="vb" autoeventwireup="false" codefile="insusmenu.ascx.vb" inherits="ascxcontrols_insusmenu" %>

<!--折叠与展开的javascript部分-->
<script type="text/javascript" language="javascript">
function showhidde(sid, evt) {
evt = evt || window.event;
var target = evt.target || evt.srcelement;
var objdiv = document.getelementbyid("div" + sid);
objdiv.style.display = objdiv.style.display == "none" ? "block" : "none";
target.title = objdiv.style.display == "none" ? "show" : "hide";
var imgid = 'img' + sid;
document.getelementbyid(imgid).src = objdiv.style.display == "none" ? "image/+.gif" : "image/-.gif";
}
</script>
<!--第一层-->
<asp:gridview id="gridviewyear" runat="server" width="100%" autogeneratecolumns="false"
onrowdatabound="gridviewyear_rowdatabound" showheader="false" borderwidth="0">
<columns>
<asp:templatefield>
<itemstyle borderwidth="0" height="25" />
<itemtemplate>

<!--下在这个绑定eval("year")，是为获取唯一id，如果你的记录有一个主键的话，可以绑定主键的字段名-->
<img id='img<%# eval("year")%>' style="border: 0px;" src="image/+.gif" onclick="showhidde('<%#eval("year")%>',event)" />

<!--下面这个绑定，是第一层显示的文字-->
<%# eval("year") & "年"%>
<div id='div<%# eval("year")%>' style="display: none;">

<!--第二层-->
<asp:gridview id="gridviewmonth" runat="server" onrowdatabound="gridviewmonth_rowdatabound" width="100%" autogeneratecolumns="false" showheader="false" borderwidth="0">
<columns>
<asp:templatefield>
<itemstyle borderwidth="0" height="25" />
<itemtemplate>
<!--这部分的解释，可参考上面。-->
<img id='img<%# eval("month")%>' style="border: 0px; padding-left: 20px;" src="image/+.gif" onclick="showhidde('<%#eval("month")%>',event)" />
<%# eval("month") & "月"%>
<div id='div<%# eval("month")%>' style="display: none;">

<!--第三层-->
<asp:gridview id="gridviewvideofile" runat="server" width="100%" autogeneratecolumns="false"
showheader="false" borderwidth="0">
<columns>
<asp:templatefield>
<itemstyle borderwidth="0" height="25" />
<itemtemplate>
<img style="border: 0px; padding-left: 40px; padding-right:5px; width: 16px; height: 16px; vertical-align: middle;" src="image/m_file.png" /><asp:hyperlink id="hyperlinkplayer" runat="server" navigateurl='<%# "~/videoplayer.aspx?videokey=" & eval("videolibrary_nbr")%>' text='<%# eval("oldfilename").substring(0, eval("oldfilename").lastindexof("."))%>' target="_blank"></asp:hyperlink>
</itemtemplate>
</asp:templatefield>
</columns>
</asp:gridview>
</div>
</itemtemplate>
</asp:templatefield>
</columns>
</asp:gridview>
</div>
</itemtemplate>
</asp:templatefield>
</columns>
</asp:gridview>

insusmenu.ascx.vb

imports system.data
imports insus.net

partial class ascxcontrols_insusmenu
inherits system.web.ui.usercontrol

'宣告实例
dim objvideolibrary as new videolibrary()

protected sub page_load(sender as object, e as eventargs) handles me.load
if not ispostback then
data_binding()
end if
end sub

private sub data_binding()
'从数据库获取数据，绑定在第一层的gridview
me.gridviewyear.datasource = objvideolibrary.getyear()
me.gridviewyear.databind()
end sub

'数据绑定在第二层的gridview
protected sub gridviewyear_rowdatabound(sender as object, e as gridviewroweventargs)


dim dvr as datarowview = directcast(e.row.dataitem, datarowview)
if e.row.rowtype = datacontrolrowtype.datarow then
if e.row.findcontrol("gridviewmonth") isnot nothing then
dim gv as gridview = directcast(e.row.findcontrol("gridviewmonth"), gridview)
objvideolibrary.year = convertdata.tosmallint(dvr("year"))
gv.datasource = objvideolibrary.getmonthbyyear()
gv.databind()
end if
end if
end sub

'数据绑定在第三层的gridview
protected sub gridviewmonth_rowdatabound(sender as object, e as gridviewroweventargs)
dim dvr as datarowview = directcast(e.row.dataitem, datarowview)
if e.row.rowtype = datacontrolrowtype.datarow then
if e.row.findcontrol("gridviewvideofile") isnot nothing then
dim gv as gridview = directcast(e.row.findcontrol("gridviewvideofile"), gridview)
objvideolibrary.year = convertdata.tosmallint(dvr("year"))
objvideolibrary.month = convertdata.totinyint(dvr("month"))
gv.datasource = objvideolibrary.getbyyearandmonth()
gv.databind()
end if
end if
end sub
end class