如何找到从特定类型 C # 继承的程序集中的所有类型

Something like:

public IEnumerable<Type> FindDerivedTypes(Assembly assembly, Type baseType)
{
return assembly.GetTypes().Where(t => baseType.IsAssignableFrom(t));
}

If you need to handle generics, that gets somewhat trickier (e.g. passing in the open List<> type but expecting to get back a type which derived from List<int>). Otherwise it's simple though :)

If you want to exclude the type itself, you can do so easily enough:

public IEnumerable<Type> FindDerivedTypes(Assembly assembly, Type baseType)
{
return assembly.GetTypes().Where(t => t != baseType &&
baseType.IsAssignableFrom(t));
}

Note that this will also allow you to specify an interface and find all the types which implement it, rather than just working with classes as Type.IsSubclassOf does.

You have to enumerate all types and check for each if it inherits the one you're looking for.

Some code like the one in this question may be useful for you.

The following method will get a collection of types that inherit a type.

C#

public IEnumerable<Type> FindSubClassesOf<TBaseType>()
{
var baseType = typeof(TBaseType);
var assembly = baseType.Assembly;


return assembly.GetTypes().Where(t => t.IsSubclassOf(baseType));
}

VB.NET

Public Function FindSubClasses(Of TBaseType)() As IEnumerable(Of Type)


Dim baseType = GetType(TBaseType)
Dim assembly = baseType.Assembly


Return From t In assembly.GetTypes()
Where t.IsSubClassOf(baseType)
Select t


End Function

If you need to include types that implement an interface see @Jon Skeet's answer.

Consider using this method (written for a PCL):

public IEnumerable<Type> FindDerivedTypes( Assembly assembly, Type baseType )
{
TypeInfo baseTypeInfo = baseType.GetTypeInfo();
bool isClass = baseTypeInfo.IsClass, isInterface = baseTypeInfo.IsInterface;


return
from type in assembly.DefinedTypes
where isClass ? type.IsSubclassOf( baseType ) :
isInterface ? type.ImplementedInterfaces.Contains( baseTypeInfo.AsType() ) : false
select type.AsType();
}