c# - Model always null on XML POST

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>