Using Reflection to Call Generic Methods in C# .NET Core

One of the powerful features of C# is its ability to use generic methods and types. However, there may be times when you need to use reflection to invoke these generic methods at runtime. In this article, we will explore how to use reflection to call generic methods in C# .NET Core. We will go over examples of how to instantiate generic types, invoke generic methods, and pass in generic type arguments.

To begin, let's start with an example of a generic method:

public class GenericMethods
{
    public static T Add<T>(T a, T b)
    {
        return (dynamic)a + (dynamic)b;
    }
}

In this example, we have a simple generic method called "Add" that takes in two generic type arguments and returns the result of adding them together. To call this method using reflection, we first need to use the "MakeGenericMethod" method to instantiate the generic method with the desired type arguments.

Type[] typeArguments = { typeof(int) };
MethodInfo addMethod = typeof(GenericMethods).GetMethod("Add").MakeGenericMethod(typeArguments);

In this case, we are instantiating the "Add" method with the type argument of "int". We can then invoke the method using the "Invoke" method, passing in the necessary arguments.

object[] arguments = { 2, 3 };
var result = addMethod.Invoke(null, arguments);
Console.WriteLine(result); // Output: 5

It's worth noting that in this example we used the dynamic keyword to ensure that the operator '+' is applied to the parameters passed to the method.

In addition to instantiating and invoking generic methods, you can also use reflection to create new instances of generic types. This is done using the "MakeGenericType" method.

Type[] typeArguments = { typeof(int) };
Type genericType = typeof(List<>).MakeGenericType(typeArguments);
object list = Activator.CreateInstance(genericType);

In this example, we are instantiating a new instance of the "List" generic type with the type argument of "int". We then use the "Activator" class to create a new instance of the generic type.

Final Words

In conclusion, reflection provides a powerful way to call generic methods and create new instances of generic types in C# .NET Core. By understanding how to use the "MakeGenericMethod" and "MakeGenericType" methods, you can add even more flexibility and functionality to your code.