在字符串 VB.net 中元素的倒数第二个实例之前插入文本

Question

我有一个类似以下布局的文档（实际上它要大得多）：

<div id="header">
    <div id="whatever">
        <div id="content">
            <p>Yes</p>
        </div>
    </div>
</div>

我正在从其他地方导入该html，但我无法控制它。我需要在倒数第二个div 之前添加额外的 html：即

<div id="header">
    <div id="whatever">
        <div id="content">
            <p>Yes</p>
        </div>
        [In here!]
    </div>
</div>

现在我已经使用 substr 和 lastindexof 完成了部分工作。但我之前无法弄清楚如何到达div。

这是我所拥有的：

Public Partial Class RightMenuControl
    Inherits System.Web.UI.UserControl
    Private dtItemsFeed As dsItems.ItemsFeedDataTable
    Private taItemsFeed As New dsItemsTableAdapters.ItemsFeedTableAdapter
    Private allText As String

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        loadData()
    End Sub
    Private Sub loadData()
        dtItemsFeed = New dsItems.ItemsFeedDataTable
        dtItemsFeed = taItemsFeed.GetCode()
        For Each rFeed As dsItems.ItemsFeedRow In dtItemsFeed
            allText = rFeed.SideCode
        Next
        Dim FirstDiv As String = allText.LastIndexOf("</div>")
        Dim LastDiv As String = allText.Substring(FirstDiv, 6)
        Dim str As String = allText
        Dim strRes As String = str.Insert(FirstDiv, "<div>extrahtml</div>")
        ltrSide.Text = strRes

    End Sub
End Class

其中打印了我的 extrahtmldiv：

<div id="header">
    <div id="whatever">
        <div id="content">
            <p>Yes</p>
        </div>
    </div>
        <div>extrahtml</div> 
</div>

汤姆

Answer 1

好的，知道它永远是倒数第二个 Div，这应该可以解决问题。

Dim LastDiv As Int = allText.LastIndexOf( "</div>" )
Dim SecondToLastDiv As Int = allText.LastIndexOf( "</div>", LastDiv ) - 1
Dim str As String = allText
Dim strRes As String = str.Insert(SecondToLastDiv, "<div>extrahtml</div>")