WCF client forgets XML declaration

I have written a WCF client for the SharePoint QueryService.

In a word, it writes a correctly-formed SOAP query. But when it is executed, the http request "forgets" the XML D开发者_JAVA技巧eclaration before the SOAP Envelope. The QueryService does not like that.

How can I force the WCF client to start the request with:

<?xml version="1.0">

This is a duplicate (although some other web service) to WCF client does not include XML declaration in HTTP POST message .

It seems that you need to implement a custom encoder. See link above for more information.