如何解析作为网络服务器响应返回的html内容，并在vb.net桌面应用程序的组合框中显示特定的标签值

Question

我正在尝试使用 Httpwebrequest/response 从 Url 获取一些数据，我收到了在 msgbox 中显示的响应。它显示整个 HTML 内容。 现在我想获取特定标签（TD 标签）值并在 vb.net 桌面应用程序的组合框中显示其所有值。

我从网络服务器获取响应的代码是：

enter code here

Imports System.IO

Imports System.Net

Imports System.Xml

Imports System.Text.Encoder

公共类登录

Private Sub login_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load


End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    End
End Sub

Private Sub Panel1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint

End Sub

Private Sub Ok_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Ok.Click
    Dim strId As String = txt_uid.Text
    Dim strPwd As String = txt_pwd.Text
    Dim oEncoder As New System.Text.ASCIIEncoding
    Dim postData As String = "UM_username=" + strId
    postData += ("&UM_password=" + strPwd)


    Dim data As Byte() = oEncoder.GetBytes(postData)
    MsgBox(postData)




    Dim webStream As Stream

    Dim webResponse As String = ""

    Dim req As HttpWebRequest

    Dim res As HttpWebResponse
    Dim Output As String
    'Dim Posit1 As Int32
    'Dim Posit2 As Int32

  req = WebRequest.Create("http://localhost/basic_framework/index.php?menu=login&UM_email=" & strId & "&UM_password=" & strPwd)

req.ContentType = "application/x-www-form-urlencoded" req.KeepAlive = False 请求方法=“POST” res = req.GetResponse()

    webStream = res.GetResponseStream()

    Dim webStreamReader As New StreamReader(webStream)
    While webStreamReader.Peek >= 0
        Output = webStreamReader.ReadToEnd()
        RichTextBox1.Text = Output

Msgbox(Output)

    End While







End Sub

End Class

此代码从 url 获取响应并将其显示在 Richtextbox 或 msgbox 中 现在我想获取一个特定的标签值（例如，td、选项值）并动态地将其显示在我的 vb.net 应用程序表单的组合框中。需要解析 html 内容然后获取该标签值。请给我建议一个方法...... 如果需要解析，如何解析html内容以仅获取vb.net形式的组合框中的特定标记值

Answer 1

好吧...如果您可以确定您的请求返回有效的 XHTML（实际上是 XML），您也许可以使用 XPath 表达式。

Answer 2

对于最复杂的情​​况（例如，AJAX 网站等），您可以将 HTMLUnit 库与 iKVM 结合使用。