How to implement Collapsible panel inside listview control for MENU in asp.net/C#

Collapsible menus using listview control in ASP.Net/C#

We have already posted a blog regarding how to create Menu control in ASP.Net/C# using List view control inside a Listview control. Here we are going to demonstrate how to implement collapsible panel extender for each categories in the menu control. Most of the websites showing menu with category and subcategory list. We can create this menu as dynamic data with ASP.Net/C#. 

Dynamic menu using ListView inside another ListView Control in ASP with collapsible panel. 

For eg : If we need to implement dynamic menu control by fetching category and subcategory from the database. In this case there is n number of category so we need to use a listview for this, but each category there is also n number of subacategories so we have to implement a another ListView for this subcategory list.

Steps to use a listview inside another listview

In our scenario, there will be a category list and under the each categories, there is n number of subcategories should be display. First of all we cretaed a ListView control which is used to hold category name and list of subcategories coming under this category. For display category name, we just included a div and bounded a ‘Name’ value to this. For listing subcategories, we created another listview control inside the itemtemplate of the first listview and included the linkbutton for display subcategory name.

And also here we are giving a facility to user to expand and collapse each subgaries list by clicking category header. So if we having largest number of categories and subcategories in the menu, user can collapse unwanted categories and hence length of the menu control will be decreased. Here are the aspx  code for the implementing menu control with categories and subcategories which including collapsible panel for each subcategory section.

<div id="boxbg">
<asp:ListView runat="server" ID="RightMenuItems" ItemPlaceholderID="PlaceHolder2">
<LayoutTemplate>
<asp:PlaceHolder runat="server" ID="PlaceHolder2" />
</LayoutTemplate>
<ItemTemplate>
<asp:Panel runat="server" ID="panelCategory" CssClass="h1header" >
<div style="float: left;">
<%# Eval("Name") %></div>
<div style="float: right; margin-top: 5px; margin-right: 5px;">
<%--<asp:Image runat="server" ID="imgCollapse" />--%></div>
</asp:Panel>
<asp:ListView runat="server" ID="subMenu" ItemPlaceholderID="PlaceHolder3"
DataSource='<%# Eval("subCategories") %>'
OnItemCommand="listViewTest_ItemCommand">
<LayoutTemplate>
<asp:Panel runat="server" ID="panelSubCategory" HorizontalAlign="center" Width="100%">
<table width="100%" cellspacing="0" border="0" cellpadding="0">
<asp:PlaceHolder runat="server" ID="PlaceHolder3" />
</table>
</asp:Panel>
<ajaxToolkit:CollapsiblePanelExtender ID="ajxColapase1" runat="server" TargetControlID="panelSubCategory"
CollapseControlID="panelCategory" ExpandControlID="panelCategory" CollapsedSize="1"
Collapsed="false" ImageControlID="imgCollapse" CollapsedImage="~/images/arrow01.gif"
ExpandedImage="~/images/arrow02.gif" />
</LayoutTemplate>
<ItemTemplate>
<tr>
<td>
<asp:LinkButton ID="lnkBtnSubMenu" runat="server" Text='<%# Eval("Name") %>' CommandName="clickSubMenu"
CommandArgument='<%# Eval("ID") %>' />
<asp:Label runat="server" ID="lblID" Visible="false" Text='<%# Eval("ID") %>' />
</td>
</tr>
</ItemTemplate>
</asp:ListView>
</ItemTemplate>
</asp:ListView>
</div>

Create a structured data to binding Menu Control (Listview inside another List view Control)

In order to bind the data source to the above ListView controls, the data should be having same structure (Category List having each category child subcategory List). For achieving this we fetch the category and subcategory from the database and created a list having required structure as follows.

DataTable dtTblCategory = new DataTable();
dtTblCategory = (new eMallBL()).getCategories(0);
DataTable dtTblSubCategory = new DataTable();
dtTblSubCategory = (new eMallBL()).getSubCategories(0, 0);
IList<eMallEntity.ItemCatagory> categories =
    new List<eMallEntity.ItemCatagory>();
for (int i = 0; i < dtTblCategory.Rows.Count; i++)
{
eMallEntity.ItemCatagory category = new eMallEntity.ItemCatagory();
category.Name = dtTblCategory.Rows[i]["Name"].ToString();
category.ID = Convert.ToInt32(dtTblCategory.Rows[i]["ID"].ToString());
IList<eMallEntity.ItemSubCatagory> subCategories =
    new List<eMallEntity.ItemSubCatagory>();
for (int j = 0; j < dtTblSubCategory.Rows.Count; j++)
{
if (dtTblSubCategory.Rows[j]["CategoryID"].ToString()
    == dtTblCategory.Rows[i]["ID"].ToString())
{
    eMallEntity.ItemSubCatagory subCategory = new eMallEntity.ItemSubCatagory();
    subCategory.Name = dtTblSubCategory.Rows[j]["Name"].ToString();
    subCategory.ID = Convert.ToInt32(dtTblSubCategory.Rows[j]["ID"].ToString());
    subCategories.Add(subCategory);
}
}
category.subCategories = subCategories;
categories.Add(category);
}
RightMenuItems.DataSource = categories;
RightMenuItems.DataBind();