Calling Generic Methods with Dynamic Type Arguments

Problem

In your scenario, you want to iterate through a collection of interfaces in a specific namespace and dynamically invoke a generic method for each interface. However, you encounter compile-time errors due to the unknown type arguments at compile time.

Solution

To dynamically call generic methods with runtime-known type arguments, you can use reflection as follows:

1. Get the generic method information: Use the Type.GetMethod method to retrieve the generic method definition.
2. Generate the generic method instance: Call the MakeGenericMethod method on the generic method definition to generate the specific method instance for the desired type argument.
3. Invoke the generic method instance: Use the Invoke method to invoke the generated generic method instance with the required arguments.

Example Code

using System;
using System.Linq;
using System.Reflection;

public class TestClass
{
    public static void CallGeneric()
    {
        Console.WriteLine($"Generic type: {typeof(T)}");
    }

    public static void Main()
    {
        var assembly = Assembly.GetExecutingAssembly();

        var interfaces = assembly.GetTypes()
            .Where(t => t.Namespace == "MyNamespace.Interfaces");

        var genericMethod = typeof(TestClass).GetMethod("CallGeneric");

        foreach (var interfaceType in interfaces)
        {
            var genericMethodInstance = genericMethod.MakeGenericMethod(interfaceType);
            genericMethodInstance.Invoke(null, null); // No target or arguments needed
        }
    }
}

In this example:

• The CallGeneric method is defined as a generic method that prints the generic type argument.
• We fetch all types from a specific namespace that inherit from MyNamespace.Interfaces.
• We use reflection to obtain the generic method CallGeneric and create a generic method instance for each interface type.
• We invoke the generic method instance without any target or arguments since it's a static method without any parameters.