C# Stream Reader convert reader to Json

To fix the issue you can do what's better , I'd say reader.GetString(0)

will be helpful for those in need You want to deserialize the returned xml into an object. This is a basic example:

//m is the string based xml representation of your object. Make sure there's something there
if (!string.IsNullOrWhiteSpace(m))
    {
        //Make a new XMLSerializer for the type of object being created
        var ser = new XmlSerializer(typeof(yourtype));

        //Deserialize and cast to your type of object
        var obj = (yourtype)ser.Deserialize(new StringReader(m));

        return obj ;
    }

may help you . Your JSON is invalid or your server responding with invalid JSON.
It should be like this

{
   "name":"rezepte",   
      "id":"1",
      "name":null,
      "alter":"Ab 6.Monat",
      "kategorie":null,
      "tageszeit":"Mittags",
      "portionen":"1 baby- und 1 Erwachsenenportion",
      "bild":"\u0000\u0000\u0000\u0000\u0000",
      "vorrat":"2",
      "zubereitungszeit":"45",
      "zubereitung0":null,
      "zubereitung1":null,
      "zubereitung2":null,
      "info":null
 }

To fix this issue In general, you can’t. #lang languages are strictly more powerful than module languages, and in fact they are a superset of module languages. A language defined with #lang simply provides a “reader” function, which accepts the body of a module as input and produces a (module ...) form as output.
For some languages in the Racket ecosystem, like #lang racket/base and #lang racket, this transformation from source to module is extremely simple. In the case of those languages, there is no difference between #lang racket/base and (module m racket/base ...). However, for some other languages, the syntax is completely different—it might not even be s-expression based! For example, consider Scribble and its LaTeX-inspired syntax.