C# Integration Request from CRM on demand

Question

I am trying to query the CRM just to see what kind contacts it holds. But no matter what I do I keep on getting HTTP server error 500. Now I have read here that it usually means that I am using the wrong URL. However I am using the same URL I use to obtain the session. I am successful at obtaining jsessionid.
Here is how my code looks like:
_strSOAPURL += ";jsessionid=" + strJsessionId;
String xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\"?><soap:Envelope xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\"xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:wsse=\"http://schemas.xmlsoap.org/ws/2002/xx/secext\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"><soap:Body><ContactWS_ContactQueryPage_Input xmlns=\"urn:crmondemand/ws/contact/\"><PageSize>10</PageSize><ListOfContact xmlns=\"urn:/crmondemand/xml/contact\"><Contact><ContactFirstName /></Contact></ListOfContact></ContactWS_ContactQueryPage_Input></soap:Body></soap:Envelope>";
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] bytesToWrite = encoding.GetBytes( xmlString );
HttpWebRequest req = (HttpWebRequest)WebRequest.Create( _strSOAPURL );
req.Method = "post";
req.ContentLength = bytesToWrite.Length;
req.Headers.Add( "SOAPAction", "\"\"" );
req.ContentType = "text/xml; charset=utf-8";
Stream newStream = req.GetRequestStream();
newStream.Write( bytesToWrite, 0, bytesToWrite.Length );
newStream.Close();
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
I am wondering is there anything on the CRM side of things I need to make sure is happening in order for me to use the service to run an integration query or am I missing any steps in my C# code?

Answer 1

I'm no expert, but you might find this suggestion helpful.
You appear to be sending a SOAPAction header with only a pair of quotation marks. From your code, it looks like you are attempting a Contact QueryPage using the generic WSDL. In that case, you should probably set the SOAPAction header to "document/urn:crmondemand/ws/contact/:ContactQueryPage".
In your code, you might change this line
req.Headers.Add( "SOAPAction", "\"\"" );
to this
req.Headers.Add( "SOAPAction", "\"document/urn:crmondemand/ws/contact/:ContactQueryPage\"" );
When you're having trouble with web services, it can be helpful to catch the response as well as the error message. The response body following an error sometimes includes helpful information.
For example:
try
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
catch (System.Net.WebException webex)
System.Net.WebResponse exresp = webex.Response;
System.IO.Stream stream = exresp.GetResponseStream();
System.IO.TextReader tr = new System.IO.StreamReader(stream);
System.Diagnostics.Debug.WriteLine("Error\r\n" + webex.ToString() + "\r\n" + tr.ReadToEnd());
With your original code, you should get an Error Message: The HTTP request did not contain a valid SOAPAction header. The value of the header was ""
I hope this helps.