Passing two parameters in action in Asp.net Core 1.1

Question

I'm trying to pass some json as string in an action but it only works for the first parameter.

Here is the action :

[HttpPost("testy")]
public string testyJson([FromBody] String json, [FromBody] String shortJson)
{
    dynamic o = MyModule.replaceInJson(json, shortJson);

    return "";
}

Here is the json I pass to both params :

"{\"id\":1}"

Here is the result

More informations :

I'm using swagger to test my api, here is what I entered

Answer 1

According to documentation

Binding formatted data from the request body

There can be at most one parameter per action decorated with [FromBody]. The ASP.NET Core MVC run-time delegates the responsibility of reading the request stream to the formatter. Once the request stream is read for a parameter, it's generally not possible to read the request stream again for binding other [FromBody] parameters.

(emphasis mine)

So the first parameter will get populated from the body but the second wont as the stream has already been read.

I would suggest creating a model to hold all the information to be passed to the action...

public class JsonModel {
    public string json { get; set;}
    public string shortJson { get; set;}
}

...and use that for the action parameter

[HttpPost("testy")]
public IActionResult testyJson([FromBody]JsonModel model) {
    var json = model.json;
    var shortJson = model.shortJson;
    dynamic o = MyModule.replaceInJson(json, shortJson);

    return Ok();
}

Answer 2

Answer found : It's blocks by the framework for performances reasons. So i'll use a list of string containing my jsons.