Reflection - from Type to Class (not instance of class)

[devvvy]

hello guys, How do I write something like this?

        string json = null;
        Type\[\] types = Assembly.GetExecutingAssembly().GetTypes();
        var carTypes = (from type in types
                         where type.IsClass && type == typeof(Car)
                         select type);
        foreach(var carType in carTypes )
        {
            string typeName = carType .Name;
            string jsonFile = typeName + ".json";
            json = File.ReadAllText(jsonFile);

            // How can I not hardcode "Porche" here and instead use "carType"? 
            IList cars = Newtonsoft.Json.JsonConvert.DeserializeObject\>(json);
        }

Here, Porche is a sub class of Car - Both "Porche" and "Car" are Class. In additional to Porche, we have Toyata, BMW, Tesla... I want to dynamically retrieve them via Reflection (avoid hardcoding) "cars" is a list of instances of cars. "carType" is Type. How can I use "carType" in JsonConvert.DerserializeObject which take List<$CLASS$> as argument? IList<someReflectionAPI(carType)> cars = Newtonsoft.Json.JsonConvert.DeserializeObjectsomeReflectionAPI(carType)>>(json); Thanks

dev

[OriginalGriff]

Why? Why not just return a List<Car> - the base type for the derived classes? All you have to do is tell Newtonsoft what you are doing:

    public abstract class Car
        {
        public int InCar { get; set; }
        }
    public class Porche : Car
        {
        public string InPorche { get; set; }
        }
    public class Toyota: Car
        {
        public int InToyota { get; set; }
        }

        Porche p = new Porche();
        p.InCar = 111;
        p.InPorche = "ppp";
        Toyota t = new Toyota();
        t.InCar = 222;
        t.InToyota = 666;
        List cars = new List() { p, t };
        JsonSerializerSettings settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All };
        string json = JsonConvert.SerializeObject(cars, settings);
        List result =JsonConvert.DeserializeObject\>(json, settings);

And it will sort it all out.

Sent from my Amstrad PC 1640 Never throw anything away, Griff Bad command or file name. Bad, bad command! Sit! Stay! Staaaay... AntiTwitter: @DalekDave is now a follower!

[F ES Sitecore]

As said, it's generally best to work with the base class if possible, but to answer your specific question you can use reflection to create and call generic methods. c# - How do I use reflection to call a generic method? - Stack Overflow[^] Other examples out there if you google.

[Richard Deeming]

devvvy wrote:

var carTypes = (from type in types
where type.IsClass && type == typeof(Car)
select type);

That's not going to do what you want. You're trying to find all sub-classes of the Car type, but your query is looking for types which are exactly the Car type. I suspect you want to use Type.IsAssignableFrom(Type)[^] :

var carTypes = (from type in types
where type.IsClass && !type.IsAbstract && type.IsAssignableFrom(typeof(Car))
select type);

JsonConvert provides a non-generic method[^] you can use to deserialize your data. To access the result, you need to use a covariant interface[^] combined with the base type. For example:

var listType = typeof(List<>).MakeGenericType(carType);
var cars = (IReadOnlyList<Car>)Newtonsoft.Json.JsonConvert.DeserializeObject(json, listType);

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