Use the
Type.IsSubclassOf
method to test all types within
a given assembly, which determines whether each type is a subclass of
the type specified in the argument to
IsSubClassOf
:
public static ArrayList GetSubClasses(string asmPath, Type baseClassType) { Assembly asm = Assembly.LoadFrom(asmPath); ArrayList subClasses = new ArrayList( ); if (baseClassType != null) { foreach(Type type in asm.GetTypes( )) { if (type.IsSubclassOf(baseClassType)) { subClasses.Add(type); } } } else { throw (new Exception(baseClassType.FullName + " does not exist in assembly " + asmPath)); } return (subClasses);
The GetSubClasses
method accepts an assembly path
string and a second string containing a fully qualified base class
name. This method returns an ArrayList
of Types
representing the subclasses of the type passed to the
baseClass
parameter.
The IsSubclassOf
method on the
Type
class allows us to determine whether the
current type is a subclass of the type passed in to this method.
To use this method, you could use the following code:
public static void FindSubclassOfType( ) { Process current = Process.GetCurrentProcess( ); // get the path of the current module string asmPath = current.MainModule.FileName; Type type = Type.GetType("CSharpRecipes.Reflection+BaseOverrides"); ArrayList subClasses = GetSubClasses(asmPath,type); // write out the subclasses for this type if(subClasses.Count > 0) { Console.WriteLine("{0} is subclassed by:",type.FullName); foreach(Type t in subClasses) { Console.WriteLine(" {0}",t.FullName); } } }
First we get the assembly path from the current process, and then we
set up use of
CSharpRecipes.Reflection+BaseOverrides
as the type
to test for subclasses. We call GetSubClasses
, and
it returns an ArrayList
that we use to produce the
following output:
CSharpRecipes.Reflection+BaseOverrides is subclassed by: CSharpRecipes.Reflection+DerivedOverrides