Determine the classes that overridden a specific method

Question

Suppose that I have this class :

 public class TestBase
 {
     public virtual bool TestMe() {  }
 }

and I have these classes that inherits from TestBase

Class A

public class TestA : TestBase
{
    public override bool TestMe() { return false; }
}

Class B

public class TestB : TestBase
{
    public override bool TestMe() { return true; }
}

Class C:

public class TestC : TestBase
{
    // this will not override the method
}

I would like to return only Class A and B because they override the Method TestMe() , How can I achieve that by creating a method in the Main class ?

  public List<string> GetClasses(object Method)
   {
     // return the list of classes A and B .
   }

Answer 1

Test for types that:

1. Extends TestBase
2. Declares a TestMe() method that's:
   • Virtual
   • Non-abstract

var baseType = typeof(TestBase);

foreach(var type in baseType.Assembly.GetTypes())
{
    if(type.IsSubclassOf(baseType))
    {
        var testMethod = type.GetMethod("TestMe");
        if(null != testMethod && testMethod.DeclaringType == type && !testMethod.IsAbstract)
        {
            if(testMethod.IsVirtual)
            {
                // `type` overrides `TestBase.TestM()`
                Console.WriteLine(type.Name + " overrides TestMe()");
            }
            else
            {
                // `type` hides `TestBase.TestM()` behind a new implementation
                Console.WriteLine(type.Name + " hides TestMe()");
            }
        }
    }
}

Given that we search types returned by baseType.Assembly.GetTypes(), this only works for subclasses defined in the same assembly/project.

To search all loaded assemblies at runtime, use AppDomain.CurrentDomain to enumerate them all first:

foreach(var type in AppDomain.CurrentDomain.GetAssemblies().SelectMany(asm => asm.GetTypes()))