Private Function getBody() As String
Dim mSw As New IO.StringWriter()
Dim mHtw As New HtmlTextWriter(mSw)
Me.nome_del_controllo_server.RenderControl(mHtw)
Return mSw.GetStringBuilder.ToString
End Function
Bisogna aggiungere anche questa sub: serve per far funzionare la Function getBody()
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As System.Web.UI.Control)
' Confirms that an HtmlForm control is rendered for the specified ASP.NET server control at run time.
End Sub
Trovato qui.