HttpWebResponse Header construction

[Hughng]

I am trying to create an POST method using HttpWebResponse from VB.NET.

 

The original code is in C++ with the following setup:

==================================

CInternetSession sess("CAutoTestComm", 1, INTERNET_OPEN_TYPE_DIRECT);

 

pHC=sess.GetHttpConnection(server, 0, port);

 

pHF=pHC->OpenRequest("POST", "/boundxml");

==================================

 

This code will generate the header below. How to I translate this code into VB.NET using HTTPWebresponse.

 

<!---------READ HEADER-------->

POST /boundxml HTTP/1.1

User-Agent: CAutoTestComm

Host: 198.xxx.yyy.zzz:8080

Content-Length: 212

Cache-Control: no-cache

 

Thank you very much for your help.

[Derek Stone]

You'll want to use HttpWebRequest, not HttpWebResponse. Use WebRequest.Create() to initialize an instance of HttpWebRequest.

[Hughng]

Thank you for your answer. Here what I did but it does not work. I keep having the exception "connection closed ..." right at the line create the streamwritter.

 

=======================

Private Function PostResult(ByVal resultmsg As String) As Boolean

Dim sw As StreamWriter

Dim sr As StreamReader

Dim myresponse As Net.HttpWebResponse

Dim myrequest As Net.HttpWebRequest = CType(Net.WebRequest.Create(m_server), Net.HttpWebRequest)

 

Try

myrequest.Method = "POST"

myrequest.ContentType = "/boundxml"

myrequest.ContentLength = resultmsg.Length

 

sw = New StreamWriter(myrequest.GetRequestStream())

sw.Write(resultmsg)

sw.Close()

 

myresponse = myrequest.GetResponse

 

If myresponse.StatusCode <> HttpStatusCode.OK Then

MsgBox("Server return: " & myresponse.StatusDescription)

sr = New StreamReader(myresponse.GetResponseStream())

m_lastStatus = sr.ReadToEnd()

Return False

End If

'End If

 

Catch Exp As Exception

MsgBox("Exception: " & Exp.Message)

m_lastStatus = "Can not connect to server"

Return False

End Try

 

Return True

 

End Function

=========================

[Hughng]

Same question:

How do I specify a target script on the http server. For example, I want to runt he script that parse my post request. It is under it is call "boundxml".

Should I put "/boundxml" into the contenttype or something where should I put it in to get the rigth response from the server?

Thank you

[Derek Stone]

You need to pass an absolute URI to the WebRequest.Create() method, not just the host's domain or IP.

 

Dim request As HttpWebRequest = WebRequest.Create("http://127.0.0.1:8080/boundxml")

 

Also, you should leave the ContentType property blank and set the UserAgent property.

[Hughng]

Thank you very much for the info. I am just wondering another thing about the Webclient class. Instead using Httpwebrequest, can I just use the Webclient and upload method to achieve the samething?

How is it difference between Httpwebrequest and Webclient classes?

[Derek Stone]

HttpWebRequest allows the developer to create specific requests. WebClient is far more generic and may just work for you.

[Hughng]

Thank you very much. Webclient work fine for me in this case. Thank you very much for all of your help Derek Stone.