c# - Extract SOAP body from a SOAP message

Question

I want to extract SOAP body from a SOAP message, I have some data in SOAP body that I have to parse in date base, so this is the code:

public string Load_XML(string SoapMessage)
{
    //check soap message
    if (SoapMessage == null || SoapMessage.Length <= 0)
        throw new Exception("Soap message not valid");

    //declare some local variable
    int iSoapBodyStartIndex = 0;
    int iSoapBodyEndIndex = 0;

    //load the Soap Message
    //U?itaj string XML-a i pretvori ga u XML
    XmlDocument doc = new XmlDocument();

    try
    {
        doc.Load(SoapMessage);
    }

    catch (XmlException ex)
    {
        WriteErrors.WriteToLogFile("WS.LOAD_DOK_LoadXML", ex.ToString());

        throw ex;
    }

    //search for the "http://schemas.xmlsoap.org/soap/envelope/" URI prefix
    string prefix = string.Empty;
    for (int i = 0; i < doc.ChildNodes.Count; i++)
    {
        System.Xml.XmlNode soapNode = doc.ChildNodes[i];
        prefix = soapNode.GetPrefixOfNamespace("http://schemas.xmlsoap.org  /soap/envelope/");

        if (prefix != null && prefix.Length > 0)
            break;
    }

    //prefix not founded. 
    if (prefix == null || prefix.Length <= 0)
        throw new Exception("Can't found the soap envelope prefix");

    //find soap body start index
    int iSoapBodyElementStartFrom = SoapMessage.IndexOf("<" + prefix + ":Body");
    int iSoapBodyElementStartEnd = SoapMessage.IndexOf(">", iSoapBodyElementStartFrom);    -> HERE I HAVE AN ERROR!!!!   
    iSoapBodyStartIndex = iSoapBodyElementStartEnd + 1;

    //find soap body end index
    iSoapBodyEndIndex = SoapMessage.IndexOf("</" + prefix + ":Body>") - 1;

    //get soap body (xml data)
    return SoapMessage.Substring(iSoapBodyStartIndex, iSoapBodyEndIndex - iSoapBodyStartIndex + 1);
}

I got an error here:

int iSoapBodyElementStartEnd = SoapMessage.IndexOf(">", iSoapBodyElementStartFrom); 

The error:

Index was out of range. Must be non-negative and less than the size of the collection.

If anyone knows how to solve this?

Answer 1

For a request like this:

String request = @"<?xml version=""1.0"" encoding=""UTF-8""?>
    <soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""
    xmlns:soapenc=""http://schemas.xmlsoap.org/soap/encoding/""
    xmlns:xsd=""http://www.w3.org/2001/XMLSchema""
    xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"">
    <soap:Body>
    <ResponseData xmlns=""urn:Custom"">some data</ResponseData>
    </soap:Body>
    </soap:Envelope>";

The following code did the work to unwrap the data and get only the <ReponseData> xml content:

XDocument xDoc = XDocument.Load(new StringReader(request));

var unwrappedResponse = xDoc.Descendants((XNamespace)"http://schemas.xmlsoap.org/soap/envelope/" + "Body")
    .First()
    .FirstNode