使用反射发现派生类型

Question

使用反射,是否可以发现从给定类型派生的所有类型？

据推测,范围将限于单个组件内.

Answer 1

和Darin几乎一样但是你走了..

    public static List<Type> FindAllDerivedTypes<T>()
    {
        return FindAllDerivedTypes<T>(Assembly.GetAssembly(typeof(T)));
    }

    public static List<Type> FindAllDerivedTypes<T>(Assembly assembly)
    {
        var derivedType = typeof(T);
        return assembly
            .GetTypes()
            .Where(t =>
                t != derivedType &&
                derivedType.IsAssignableFrom(t)
                ).ToList();

    } 

用过:

var output = FindAllDerivedTypes<System.IO.Stream>();
            foreach (var type in output)
            {
                Console.WriteLine(type.Name);
            }

输出:

NullStream
SyncStream
__ConsoleStream
BufferedStream
FileStream
MemoryStream
UnmanagedMemoryStream
PinnedBufferMemoryStream
UnmanagedMemoryStreamWrapper
IsolatedStorageFileStream
CryptoStream
TailStream

Answer 2

var derivedTypes = from t in Assembly.GetExecutingAssembly().GetTypes()
                   where t.IsSubclassOf(typeof(A))
                   select t;

Answer 3

var types = Assembly
    .GetExecutingAssembly()
    .GetTypes()
    .Where(t => typeof(SomeBaseType).IsAssignableFrom(t) && 
                t != typeof(SomeBaseType))
    .ToArray();

Answer 4

我重写了 @Hath 的优秀答案作为扩展方法：

public static class TypeExtensions
{
    public static List<Type> GetAllDerivedTypes(this Type type)
    {
        return Assembly.GetAssembly(type).GetAllDerivedTypes(type);
    }

    public static List<Type> GetAllDerivedTypes(this Assembly assembly, Type type)
    {
        return assembly
            .GetTypes()
            .Where(t => t != type && type.IsAssignableFrom(t))
            .ToList();
    }
}

用法：

var listOfDerived = typeof(MyClass).GetAllDerivedTypes();