SimplePostVariableParameterBindingExtended

Why do we need it?

Consider this code :

[HttpPost]
[MultiParameterSupport]
public HttpResponseMessage Login(int MasterEntity, string username, string password, string userAgent)
{
	//...logics...
}

This method gets its parameters from the body via POST.

In WebAPI you can't(!) get (nativly) multiple form parameters via [frombody]. Rick started doing it : http://weblog.west-wind.com/posts/2012/Sep/11/Passing-multiple-simple-POST-Values-to-ASPNET-Web-API

But it didn't support nullables types. So you couldn't do :

public HttpResponseMessage Login(int? MyInt,int A)
{ 
	//...logics...
}

Also, it didn't support a situation where a person sends JSON. there was no code for this situation:

// only read if there's content and it's form data
if (contentType == null || contentType.MediaType != "application/x-www-form-urlencoded")
{
    // Nope no data
    result = null;
}
else
{
    // parsing the string like firstname=Hongmei&lastname=ASDASD            
    result = request.Content.ReadAsFormDataAsync().Result;
}  

So now you can(!) send JSON to the controller both via application/x-form-urlencoded (a=1&b=2&c=) and also via application/json {"a":1,"b":2} or {"a":1,"b":2,"c":null}

NB webAPI can work with JSON (obviously) , but you need:

Login(NyLoginParams mlp)
{
	//...logics...
}

Assuming you need to expose Many existsing services which doesnt has MyMethodParams class - you'll need this code .