GridView多层嵌套和折叠与展开

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" %>                                                                     '  class="lazyload" src="https://www.mshxw.com/file/upload/202104/26/215123740.png" data-original="Image/+.gif" onclick="ShowHidde('<%#eval("Year")%>',event)" />                                                                <%# eval("Year") & "年"%>                ' >                                                                                                                                                                                                                                                                                            '  class="lazyload" src="https://www.mshxw.com/file/upload/202104/26/215123740.png" data-original="Image/+.gif" onclick="ShowHidde('<%#eval("Month")%>',event)" />                                    <%# eval("Month") & "月"%>                                    ' >                                                                                                                                                                                                                                                                                                                                                                                    ' Text='<%# eval("OldFileName").Substring(0, eval("OldFileName").LastIndexOf("."))%>' Target="_blank">                                                                                                                                                                                                                                                                                                                                                                            

InsusMenu.ascx.vb

imports System.Dataimports Insus.NETPartial 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 SubEnd Class