WCF: Is the order of elements in an XML that is posted to a Rest service important?

I have been debugging a Rest Service for a while and I 开发者_StackOverflowhave realized that if I post (via POST method) this file

<RegionDTO xmlns="http://www.mysite.com/api">
 <id>4</id> 
 <country_id>1</country_id>
 <name>This is the name</name>
</RegionDTO>

I get this RegionDTO object populated:

RegionDTO.id --> 4

RegionDTO.name --> "This is the name"

RegionDTO.country_id --> null

And If I re-order the elements of this xml to this:

<RegionDTO xmlns="http://www.mysite.com/api">
<country_id>1</country_id>
<id>4</id> 
<name>This is the name</name>
</RegionDTO>

I get this RegionDTO object correctly populated:

RegionDTO.id --> 4

RegionDTO.name --> "This is the name"

RegionDTO.country_id --> 1

Technical specification? .NET 4, self hosted

Finally I found the answer:

The default serializer used by WCF is "DataContractSerializer". By default, Local elements are mapped in alphabetical order

Ref: http://www.pluralsight-training.net/microsoft/olt/Course/Toc.aspx?n=wcf-design-concepts (in "[DataContract] mapping" chapter)