WebService SOAP Encoding UTF-16 instead of UTF-8

Question

Is it possible to force a WebService in C# .NET to use encoding UTF-16 instead of UTF-8?

I have created a simple WebService which receives a XML Document.

WebService.asmx

public class WebApplication1 : WebService
{
    [WebMethod(Description = "Test")]
    public string Test(XmlDocument xmlDocument)
    {
        return "Test";
    }
}

Output

POST /WebService.asmx HTTP/1.1
Host: localhost
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://tempuri.org/Test"

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <Test xmlns="http://tempuri.org/">
      <xmlDocument>xml</xmlDocument>
    </Test>
  </soap:Body>
</soap:Envelope>

If I try an pass an XML Document that is UTF-16 encoded, I get the following error:

XML Content:
<?xml version="1.0" encoding="utf-16"?> <Affiliate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" leadinnumber="ABCDABCD" xmlns:xsd="http://www.w3.org/2001/XMLSchema" mediaid="30000">
  <Details>
    <Amount>5000</Amount>
    <FirstName>Delivery</FirstName>
    <Surname>Testing</Surname>
    <Tel>02034056978</Tel>
    <Email>[email protected]</Email>
  </Details>
</Affiliate>

Post Response
<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <soap:Body>
    <soap:Fault>
      <soap:Code>
        <soap:Value>soap:Receiver</soap:Value>
      </soap:Code>
      <soap:Reason>
        <soap:Text xml:lang="en">System.Web.Services.Protocols.SoapException: Server was unable to process request. ---&gt; System.Xml.XmlException: There is no Unicode byte order mark. Cannot switch to Unicode. at System.Xml.XmlTextReaderImpl.Throw(Exception e) at System.Xml.XmlTextReaderImpl.ThrowWithoutLineInfo(String res) at System.Xml.XmlTextReaderImpl.CheckEncoding(String newEncodingName) at System.Xml.XmlTextReaderImpl.ParseXmlDeclaration(Boolean isTextDecl) at System.Xml.XmlTextReaderImpl.Read() at System.Web.Services.Protocols.SoapServerProtocol.SoapEnvelopeReader.Read() at System.Xml.XmlReader.MoveToContent() at System.Web.Services.Protocols.SoapServerProtocol.SoapEnvelopeReader.MoveToContent() at System.Web.Services.Protocols.SoapServerProtocolHelper.GetRequestElement() at System.Web.Services.Protocols.Soap12ServerProtocolHelper.RouteRequest() at System.Web.Services.Protocols.SoapServerProtocol.RouteRequest(SoapServerMessage message) at System.Web.Services.Protocols.SoapServerProtocol.Initialize() at System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean&amp; abortProcessing) --- End of inner exception stack trace ---</soap:Text>
      </soap:Reason>
      <soap:Detail />
    </soap:Fault>
  </soap:Body>
</soap:Envelope>

Any help would be much appreciated :-)

Solution

You have to configure your web service. Go to globalization section of Web.config and make UTF-16 instead of UTF-8. The requestEncoding and responseEncoding attributes of the globalization tag should be set to UTF-16.

<globalization requestEncoding="utf-8" responseEncoding="utf-8"/>

must be converted to

<globalization requestEncoding="utf-16" responseEncoding="utf-16"/>

This change will allow the web service to accept request and send response in UTF-16.

EDIT

For setting the encoding manually through code you can use following code:

        // Set the path of the config file.
        string configPath = "";            
        Configuration config = WebConfigurationManager.OpenWebConfiguration(configPath);
        GlobalizationSection configSection = (GlobalizationSection)config.GetSection("system.web/globalization");            
        configSection.RequestEncoding = Encoding.Unicode;
        configSection.ResponseEncoding = Encoding.Unicode;