无法使用WebRequest / WebResponse连接到WebService

Question

尝试连接到网络服务失败。

用户输入WebService的网址，在我的情况下是http://localhost:61302/WebService/XYZService.asmx，输入用户名/登录信息（出于测试目的，我使用alexTest / deJh8detRKw=），然后点击Test Connection按钮，应连接到public int TestConnect(string userName, string password) Web服务方法。

这是按钮点击的处理程序

 Private Sub Test_Connection_2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TestButton_2.Click
        If URL_Field.Text.Trim <> "" Then
            ' URL string is not empty

            Try 'Attempt to connect to Web Services
                'TODO: Add the Uri(URL_Field.Text.Trim + function name)
                Dim base_uri As New Uri(URL_Field.Text.Trim) 'URL Server
                Dim combined_uri As New Uri(URL_Field.Text.Trim + "/TestConnect")
                'TODO: Parse the service_uri to make sure it is syntat. correct URL or handle the exception during constr

                Dim web_request As HttpWebRequest = WebRequest.Create(combined_uri)
                web_request.Method = "POST"
                web_request.ContentType = "application/x-www-form-urlencoded"
                Dim string_data As String = String.Format("userName={0}&password={1}", userNameBox.Text.Trim(), Uri.EscapeDataString(passBox.Text.Trim()))
                Dim byte_data() As Byte = ASCIIEncoding.ASCII.GetBytes(string_data)
                web_request.ContentLength = byte_data.Length

                'Get Response 
                Dim web_resp As HttpWebResponse = web_request.GetResponse()
                Dim streamReader As New StreamReader(web_resp.GetResponseStream(), Encoding.UTF8)
                Dim response_string As String = streamReader.ReadToEnd()

它会跑到Dim web_resp As HttpWebResponse = web_request.GetResponse()行并停止。我没有例外，没有错误，没有。 Web服务工作，因为我能够通过浏览器测试它。但是，当我运行代码时，不会停止在Web方法上的断点处，即永远不会调用web方法。