Basetype的BaseType

Question

this is my first question here so I hope I can articulate it well and hopefully it won't be too mind-numbingly easy.

I have the following class SubSim which extends Sim , which is extending MainSim . In a completely separate class (and library as well) I need to check if an object being passed through is a type of MainSim . So the following is done to check;

Type t = GetType(sim);
//in this case, sim = SubSim
if (t != null)
{
  return t.BaseType == typeof(MainSim);
}

Obviously t.BaseType is going to return Sim since Type.BaseType gets the type from which the current Type directly inherits.

Short of having to do t.BaseType.BaseType to get MainSub , is there any other way to get the proper type using .NET libraries? Or are there overrides that can be redefined to return the main class?

Thank you in advance

Answer 1

There are 4 related standard ways:

sim is MainSim;
(sim as MainSim) != null;
sim.GetType().IsSubclassOf(typeof(MainSim));
typeof(MainSim).IsAssignableFrom(sim.GetType());

You can also create a recursive method:

bool IsMainSimType(Type t)
 { if (t == typeof(MainSim)) return true;   
   if (t == typeof(object) ) return false;
   return IsMainSimType(t.BaseType);
 }

Answer 2

if (sim is MainSim)

is all you need. "is" looks up the inheritance tree.

Answer 3

使用is关键字 ：

return t is MainSim;

Answer 4

How about "is"?

http://msdn.microsoft.com/en-us/library/scekt9xw(VS.71).aspx

Answer 5

The 'is' option didn't work for me. It gave me the warning; "The given expression is never of the provided ('MainSim') type", I do believe however, the warning had more to do with the framework we have in place. My solution ended up being:

return t.BaseType == typeof(MainSim) || t.BaseType.IsSubclassof(typeof(MainSim));

Not as clean as I'd hoped, or as straightforward as your answers seemed. Regardless, thank you everyone for your answers. The simplicity of them makes me realize I have much to learn.