问使用UpdatePanel在页面上从web控件注册样式表

EN

    <System.Runtime.CompilerServices.Extension()> _
    Public Sub RegisterStylesheetInclude(ByVal scriptManager As ScriptManager, ByVal page As Page, ByVal url As String)
        Dim css = "var cssNode = document.createElement('link');" & _
         "cssNode.type = 'text/css';" & _
         "cssNode.rel = 'stylesheet';" & _
         "cssNode.href = '" & url & "';" & _
         "document.getElementsByTagName('head')[0].appendChild(cssNode);"

        scriptManager.RegisterClientScriptBlock(page, page.GetType(), url, css, True)
    End Sub

    <System.Runtime.CompilerServices.Extension()> _
    Public Sub RegisterStylesheetInclude(ByVal clientScriptManager As ClientScriptManager, ByVal page As Page, ByVal url As String)
        Dim found = page.Header.Controls.OfType(Of HtmlLink).Any(Function(m) m.Href = url)

        If Not found Then
            Dim link As New HtmlLink()
            link.Href = url
            link.Attributes("type") = "text/css"
            link.Attributes("rel") = "stylesheet"
            page.Header.Controls.Add(link)
        End If
    End Sub