Question

I’m currently working on an integration between systems and I’ve decided to use WebApi for it, but I’m running into an issue…

Let’s say I have a model:

public class TestModel
{
    public string Output { get; set; }
}

and the POST method is:

public string Post(TestModel model)
{
    return model.Output;
}

I create a request from Fiddler with the header:

User-Agent: Fiddler
Content-Type: "application/xml"
Accept: "application/xml"
Host: localhost:8616
Content-Length: 57

and body:

<TestModel><Output>Sito</Output></TestModel>

The model parameter in the method Post is always null and I have no idea why.
Does anyone have a clue?

Answer 1

Two things:

1. You don’t need quotes "" around the content type and accept header values in Fiddler:

   User-Agent: Fiddler
   Content-Type: application/xml
   Accept: application/xml
   

2. Web API uses the DataContractSerializer by default for xml serialization. So you need to include your type’s namespace in your xml:

   <TestModel 
   xmlns="http://schemas.datacontract.org/2004/07/YourMvcApp.YourNameSpace"> 
       <Output>Sito</Output>
   </TestModel> 
   

   Or you can configure Web API to use XmlSerializer in your WebApiConfig.Register:

   config.Formatters.XmlFormatter.UseXmlSerializer = true;
   

   Then you don’t need the namespace in your XML data:

    <TestModel><Output>Sito</Output></TestModel>