VB.NET以编程方式在标记之间添加代码

我有一个自定义控件,它在异步回发上为我做了一些工作。通常,我会使用ASPX页面上的以下代码直接从表示端调用控件:

<mytag:CustomControl runat="server">
    html (or other text) goes here
</mytag:CustomControl>

但是,在我当前的应用程序中,我需要从codebehind动态创建控件,使用类似于以下代码的代码:

Dim myControl As myClass.CustomControl = New myClass.CustomControl
myControl.ID = "someID"
myControl.?????? = "html (or other text) goes here"
Me.Controls.Add(myControl)

当动态地将控件添加到页面时,如果控件是以正常的非动态方式添加的,如何添加通常在开始和结束标记之间的信息?

谢谢

以下是实际控制:

Protected Overloads Overrides Sub Render(ByVal writer As HtmlTextWriter)
    Dim scriptmanagerPage As ScriptManager = ScriptManager.GetCurrent(Page)
    If scriptmanagerPage Is Nothing Then
        'Do nothing
    Else
        'See if we are in a postback
        If scriptmanagerPage.IsInAsyncPostBack Then
            'We are in a postback; register the script
            Dim stringbuilderWorking As New StringBuilder()
            MyBase.Render(New HtmlTextWriter(New StringWriter(stringbuilderWorking)))
            Dim stringScript As String = stringbuilderWorking.ToString()
            ScriptManager.RegisterStartupScript(Me, GetType(ScanWorkXAJAX), UniqueID, stringScript, False)
        Else
            'Not in a postback
            MyBase.Render(writer)
        End If 'In an async postback
    End If 'Scriptmanager present

End Sub