Vb.Net元素.InvokeMember（“单击”）

我正在尝试自动登录并在youtube上搜索一些关键字，登录并键入关键字的部分是有效的，但在写入关键字后我无法进行单击搜索这是我的代码：

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        WebBrowser1.Navigate("https://accounts.google.com/ServiceLogin?uilel=3&service=youtube&passive=true&continue=http%3A%2F%2Fwww.youtube.com%2Fsignin%3Faction_handle_signin%3Dtrue%26feature%3Dsign_in_button%26hl%3Den_US%26next%3D%252F%26nomobiletemp%3D1&hl=en_US")
    End Sub

    Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted

        Dim theElementCollection As HtmlElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
        For Each curElement As HtmlElement In theElementCollection
            Dim controlName As String = curElement.GetAttribute("id").ToString
            If controlName = "Email" Then
                curElement.SetAttribute("Value", "email here")
            End If
        Next

        theElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
        For Each curElement As HtmlElement In theElementCollection
            Dim controlName As String = curElement.GetAttribute("id").ToString
            If controlName = "Passwd" Then
                curElement.SetAttribute("Value", "password here")
            End If
        Next


        theElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
        For Each curElement As HtmlElement In theElementCollection
            If curElement.GetAttribute("value").Equals("Sign in") Then
                curElement.InvokeMember("click")
                'Javascript has a click method for we need to invoke on the current submit button element.  
            End If
        Next


        theElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
        For Each curElement As HtmlElement In theElementCollection
            Dim controlName As String = curElement.GetAttribute("id").ToString
            If controlName = "masthead-search-term" Then
                curElement.SetAttribute("Value", "Keyword Here")

            End If
        Next



        For Each Element As HtmlElement In WebBrowser1.Document.GetElementsByTagName("Search")
            'Depending on how the source code is formatted on the tag, you may also try Element.OuterHTML, Element.InnerText and Element.OuterText in the line below
            If Element.InnerHtml.Contains("class=""yt-uix-button-content""") Then
                Element.InvokeMember("click")
                Exit For
            End If
        Next Element

    End Sub
End Class

嘿，也许这样行得通：

theElementCollection = WebBrowser1.Document.GetElementsByTagName("button")
        For Each curElement As HtmlElement In theElementCollection
            Dim controlName As String = curElement.GetAttribute("id").ToString
            If controlName = "search-btn" Then
                curElement.InvokeMember("click")
            End If
        Next