为什么FireSharp无法收听流媒体

Question

我刚刚在Windows应用程序中试用过FireSharp。我可以毫无问题地连接，查询和更新数据。但是，我无法让监听器正常工作。

在OnSync调用创建侦听器之后，objListener = Nothing。没有错误，只是不返回任何值。

*** OBJECT ***
Public Class AlertData
    Private new_value As String = Nothing

    Public Property NewValue() As String
        Get
            Return new_value
        End Get
        Set(ByVal value As String)
            new_value = value
        End Set
    End Property


End Class

*** CONNECTING\LISTENING ***
            objConfig = New FirebaseConfig()
            With objConfig
                .AuthSecret = "<My Secret>"
                .BasePath = "<My URL>"
            End With

            objClient = New FireSharp.FirebaseClient(objConfig)

            If objClient IsNot Nothing Then
                Dim objListener As EventStreamResponse = Await objClient.OnAsync("alert", Function(s, args, context) {txtUpdate.Text = args.ToString})
            End If


*** READING ***
        Dim objResult As AlertData
        Dim objResponse As FireSharp.Response.FirebaseResponse
        Try
            objResponse = Await objClient.GetAsync("alert")
            objResult = objResponse.ResultAs(Of AlertData)
            txtUpdate.Text = objResult.NewValue

        Catch ex As Exception
            strErrMsg = ex.Message
        End Try


*** WRITING ***
        Dim objData As AlertData
        Dim objResult As AlertData
        Dim objResponse As SetResponse
        Try

            objData = New AlertData()
            objData.NewValue = Now.ToString("yyyy-MM-dd hh:mm:ss")

            objResponse = Await objClient.SetAsync("alert", objData)
            objResult = objResponse.ResultAs(Of AlertData)

        Catch ex As Exception
            strErrMsg = ex.Message
        End Try