如何使DataContractJsonSerializer将对象序列化为字符串?

I have a struct in C# that wraps a guid. I'm using DataContractJsonSerializer to serialize an object containing an instance of that class. When I was using a guid directly, it was serialized as a plain string, but now it's serialized as a name/value pair. Here's an NUnit test and supporting code that demonstrates the problem:I have a struct in C# that wraps a guid. I'm us