Generating a list of child classes with reflection in .NET 3.5

问题

At runtime, I would like to specify a parent class, and then the program would generate a list of all children classes (of however many generations). For example, if I had Entity as a parent, and Item:Entity and Actor:Entity, there would be two strings, "Actor" and "Item".

I see that System.Reflection.TypeInfo is exactly what I am looking for. However, it appears this is exclusive to .NET 4.5, and my environment is unfortunately stuck at 3.5.

Is there an alternative way to do this in .NET 3.5, or should I consider an upgrade?

回答1:

var pType = typeof(Entity);
IEnumerable<string> children = Enumerable.Range(1, iterations)
   .SelectMany(i => Assembly.GetExecutingAssembly().GetTypes()
                    .Where(t => t.IsClass && t != pType
                            && pType.IsAssignableFrom(t))
                    .Select(t => t.Name));

Demo

回答2:

One possible way would utilize the Type.IsAssignableFrom method. You would loop over all types, and select those for which it is true.

Basically, it would be something like

Type parent = Type.GetType("Entity");
Type[] types = Assembly.GetExecutingAssembly().GetTypes(); // Maybe select some other assembly here, depending on what you need
Type[] inheritingTypes = types.Where(t => parent.IsAssignableFrom(t));

I don't have a compiler available at this time, so I can't verify it, but it should be mostly correct

来源：https://stackoverflow.com/questions/13896716/generating-a-list-of-child-classes-with-reflection-in-net-3-5