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。
代码如下:

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> 
 
 代码如下:

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