Probem passing string type to web service method

I don't know if this is the correct forum to ask this question. But I have an asp.net web service with a method method GetCapital() as follows:

Code:

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        [WebMethod]
        public string GetCapital(  string inp  )
        {
            XmlTextReader reader = new XmlTextReader("c:\\Temp\\Sample.xml");
            string ret ="";
            reader.MoveToContent();
            while (reader.Read())
            {
                if (reader.NodeType == XmlNodeType.Element)
                {
                    // check if the element has any attributes
                    if (reader.HasAttributes)
                    {
                        // move to the first attribute
                        reader.MoveToFirstAttribute();
                        for (int i = 0; i < reader.AttributeCount; i++)
                        {
                            // read the current attribute
                            reader.MoveToAttribute(i);
                            if (reader.Value == inp)
                            {
                              ret = reader.GetAttribute(1);
                              return ret;
                             
                            }                           
                        }
                    }
                }
            }
            return ret;
        }
    }

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Forget the logic. I am calling this web service from a VC++ client using SOAP as follows:

Code:

---


        std::string csSoapString;       
        csSoapString =  "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
        csSoapString += "<soap:Envelope xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\"";
        csSoapString += " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance \"";
        csSoapString += " xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">";
        csSoapString += "<soap:Body>";
        csSoapString += "<GetCapital xmlns=\"http://tempuri.org/\"/>";
        csSoapString += "<inp xsi:type=\"xsd:string\">";
        csSoapString += "USA";
        csSoapString += "</inp>";
        csSoapString += "</soap:Body>";
        csSoapString += "</soap:Envelope>";



int nContentLength = csSoapString.length();
                                CString csLength;
                                csLength.Format( _T( "&#37;d" ),nContentLength );                               
                                char temp[10];
                          _itoa_s(csSoapString.size(), temp, 10,  10);
                                string csSoapAction;
                                csSoapAction = "Content-Type: text/xml; charset=utf-8";
                                csSoapAction += "Content-Length: ";
                                csSoapAction += temp;
                                csSoapAction += "\r\n\r\n";
                                csSoapAction += "SOAPAction: \"";
                                csSoapAction += "http://tempuri.org/GetCapital";
                                csSoapAction +=  "\"\0\r\n\r\n";

BOOL bSent = HttpSendRequestA(hRequest, csSoapAction.c_str(), csSoapAction.size(), (LPVOID )csSoapString.c_str(), csSoapString.size());

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But when I call the GetCapital method from the client <i get the follwing error in the response :

Code:

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Object reference not set to an instance of object.

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The problem is the paramater "USA" I am passing from the client is not received in the web service. In the web service the input argument inp is null. What is wrong with the SOAP request ? How should I correct the SOAP request?

Thanks in advance.

Hi!

By myself i never used .net Web services with C++ client, but may be this will be useful for you: http://www.codeguru.com/cpp/com-tech...icle.php/c3945