Is it possible to modify how message contracts are generated when adding a WCF service reference in Visual Studio 2010? Specifically I want the request and response objects to have properties instead of public fields.
I have no control over the WCF service itself, just the client.
You can't control the code in the generated proxy. If you want, you can do the proxy generation yourself, using the MetadataExchangeClient / ServiceContractGenerator classes. They'll give you a CodeDom object containing the code which you can modify (i.e., change fields into properties). There's an example of using the MEC/SCG classes in the MSDN forum post at http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/14100bbb-9a73-4bcc-b513-088bb2e5ec65.