Posts Text to a defined Mattermost webhook (VB.NET)

mattermost-webhook-connector.net.vb

Imports System.IO
Imports System.Text
Imports System.Net

Public Class mattermost
    ''' <summary>
    ''' Posts Text to a defined Mattermost webhook
    ''' </summary>
    ''' <param name="sWebhookURL"></param>
    ''' <param name="sText"></param>
    ''' <param name="sUser"></param>
    ''' <param name="sChannel"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function _post2Mattermost(ByVal sWebhookURL As Uri, ByVal sText As String, _
                                            ByVal sUser As String, ByVal sChannel As String) As String
        Dim jsonString As String = String.Format("{{""username"": ""{0}"", ""text"": ""{1}"", " + _
                                                 """channel"": ""{2}""}}", sUser, sText, sChannel)
        ServicePointManager.ServerCertificateValidationCallback = Function() True

        Dim data = Encoding.UTF8.GetBytes(jsonString)
        Dim req As WebRequest = WebRequest.Create(sWebhookURL)
        req.ContentType = "application/json"
        req.Method = "POST"
        req.ContentLength = data.Length

        Using requestWriter As StreamWriter = New StreamWriter(req.GetRequestStream())
            requestWriter.Write(jsonString)
        End Using

        Dim response = req.GetResponse().GetResponseStream()

        Dim reader As New StreamReader(response)
        Dim res = reader.ReadToEnd()
        reader.Close()
        response.Close()
        Return res
    End Function

End Class

Module1.vb

Imports mattermost_webhook_connector.net

Module Module1

    Sub Main()
        Dim res As String = mattermost._post2Mattermost(New Uri("https://<your webhook URL goes here>"), _
                                    "Hey dude", "god of dotnet", "")
        Debug.WriteLine("Response: " + res)
    End Sub

End Module