我研究了其中一些样本，发现它们在某些情况下是缺乏的。这个版本适用于所有类型的泛型:类型、接口及其类型定义。

public static bool InheritsOrImplements(this Type child, Type parent)
{
    parent = ResolveGenericTypeDefinition(parent);

    var currentChild = child.IsGenericType
                           ? child.GetGenericTypeDefinition()
                           : child;

    while (currentChild != typeof (object))
    {
        if (parent == currentChild || HasAnyInterfaces(parent, currentChild))
            return true;

        currentChild = currentChild.BaseType != null
                       && currentChild.BaseType.IsGenericType
                           ? currentChild.BaseType.GetGenericTypeDefinition()
                           : currentChild.BaseType;

        if (currentChild == null)
            return false;
    }
    return false;
}

private static bool HasAnyInterfaces(Type parent, Type child)
{
    return child.GetInterfaces()
        .Any(childInterface =>
        {
            var currentInterface = childInterface.IsGenericType
                ? childInterface.GetGenericTypeDefinition()
                : childInterface;

            return currentInterface == parent;
        });
}

private static Type ResolveGenericTypeDefinition(Type parent)
{
    var shouldUseGenericType = true;
    if (parent.IsGenericType && parent.GetGenericTypeDefinition() != parent)
        shouldUseGenericType = false;

    if (parent.IsGenericType && shouldUseGenericType)
        parent = parent.GetGenericTypeDefinition();
    return parent;
}

下面是单元测试:

protected interface IFooInterface
{
}

protected interface IGenericFooInterface<T>
{
}

protected class FooBase
{
}

protected class FooImplementor
    : FooBase, IFooInterface
{
}

protected class GenericFooBase
    : FooImplementor, IGenericFooInterface<object>
{

}

protected class GenericFooImplementor<T>
    : FooImplementor, IGenericFooInterface<T>
{
}


[Test]
public void Should_inherit_or_implement_non_generic_interface()
{
    Assert.That(typeof(FooImplementor)
        .InheritsOrImplements(typeof(IFooInterface)), Is.True);
}

[Test]
public void Should_inherit_or_implement_generic_interface()
{
    Assert.That(typeof(GenericFooBase)
        .InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}

[Test]
public void Should_inherit_or_implement_generic_interface_by_generic_subclass()
{
    Assert.That(typeof(GenericFooImplementor<>)
        .InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}

[Test]
public void Should_inherit_or_implement_generic_interface_by_generic_subclass_not_caring_about_generic_type_parameter()
{
    Assert.That(new GenericFooImplementor<string>().GetType()
        .InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}

[Test]
public void Should_not_inherit_or_implement_generic_interface_by_generic_subclass_not_caring_about_generic_type_parameter()
{
    Assert.That(new GenericFooImplementor<string>().GetType()
        .InheritsOrImplements(typeof(IGenericFooInterface<int>)), Is.False);
}

[Test]
public void Should_inherit_or_implement_non_generic_class()
{
    Assert.That(typeof(FooImplementor)
        .InheritsOrImplements(typeof(FooBase)), Is.True);
}

[Test]
public void Should_inherit_or_implement_any_base_type()
{
    Assert.That(typeof(GenericFooImplementor<>)
        .InheritsOrImplements(typeof(FooBase)), Is.True);
}

试试这段代码

static bool IsSubclassOfRawGeneric(Type generic, Type toCheck) {
    while (toCheck != null && toCheck != typeof(object)) {
        var cur = toCheck.IsGenericType ? toCheck.GetGenericTypeDefinition() : toCheck;
        if (generic == cur) {
            return true;
        }
        toCheck = toCheck.BaseType;
    }
    return false;
}

这个游戏已经晚了…我对JarodPar的答案也有另一种排列。

下面是Type. issubclassof (Type)，由reflector提供:

    public virtual bool IsSubclassOf(Type c)
    {
        Type baseType = this;
        if (!(baseType == c))
        {
            while (baseType != null)
            {
                if (baseType == c)
                {
                    return true;
                }
                baseType = baseType.BaseType;
            }
            return false;
        }
        return false;
    }

由此，我们看到它并没有做任何过于疯狂的事情，并且类似于JaredPar的迭代方法。到目前为止，一切顺利。这是我的版本(免责声明:没有彻底测试，所以如果你发现问题，请告诉我)

    public static bool IsExtension(this Type thisType, Type potentialSuperType)
    {
        //
        // protect ya neck
        //
        if (thisType == null || potentialSuperType == null || thisType == potentialSuperType) return false;

        //
        // don't need to traverse inheritance for interface extension, so check/do these first
        //
        if (potentialSuperType.IsInterface)
        {
            foreach (var interfaceType in thisType.GetInterfaces())
            {
                var tempType = interfaceType.IsGenericType ? interfaceType.GetGenericTypeDefinition() : interfaceType;

                if (tempType == potentialSuperType)
                {
                    return true;
                }
            }
        }

        //
        // do the concrete type checks, iterating up the inheritance chain, as in orignal
        //
        while (thisType != null && thisType != typeof(object))
        {
            var cur = thisType.IsGenericType ? thisType.GetGenericTypeDefinition() : thisType;

            if (potentialSuperType == cur)
            {
                return true;
            }

            thisType = thisType.BaseType;
        }
        return false;
    }

基本上这只是System的一个扩展方法。类型-我这样做是为了故意将“thisType”类型限制为具体类型，因为我的直接用法是对类型对象的LINQ查询“where”谓词。我相信所有聪明的人都可以把它归结为一个有效的，通用的静态方法，如果你需要:)代码做了一些事情，答案的代码没有

open's it up to to general "extension" - i'm considering inheritance (think classes) as well as implementation (interfaces); method and parameter names are changed to better reflect this input null-validation (meah) input of same type (a class cannot extend itself) short-circuit execution if Type in question is an interface; because GetInterfaces() returns all implemented interfaces (even ones implemented in super-classes), you can simply loop through that collection not having to climb the inheritance tree

其余部分基本上与JaredPar的代码相同

下面是我创建的一个小方法，用于检查对象是否派生于特定类型。对我来说太棒了!

internal static bool IsDerivativeOf(this Type t, Type typeToCompare)
{
    if (t == null) throw new NullReferenceException();
    if (t.BaseType == null) return false;

    if (t.BaseType == typeToCompare) return true;
    else return t.BaseType.IsDerivativeOf(typeToCompare);
}

添加到@jaredpar的答案中，下面是我用来检查接口的方法:

public static bool IsImplementerOfRawGeneric(this Type type, Type toCheck)
{
    if (toCheck.GetTypeInfo().IsClass)
    {
        return false;
    }

    return type.GetInterfaces().Any(interfaceType =>
    {
        var current = interfaceType.GetTypeInfo().IsGenericType ?
                    interfaceType.GetGenericTypeDefinition() : interfaceType;
        return current == toCheck;
    });
}

public static bool IsSubTypeOfRawGeneric(this Type type, Type toCheck)
{
    return type.IsInterface ?
          IsImplementerOfRawGeneric(type, toCheck)
        : IsSubclassOfRawGeneric(type, toCheck);
}

Ex:

Console.WriteLine(typeof(IList<>).IsSubTypeOfRawGeneric(typeof(IList<int>))); // true

JaredPar的代码可以工作，但只适用于一个继承级别。要获得无限级别的继承，请使用以下代码

public bool IsTypeDerivedFromGenericType(Type typeToCheck, Type genericType)
{
    if (typeToCheck == typeof(object))
    {
        return false;
    }
    else if (typeToCheck == null)
    {
        return false;
    }
    else if (typeToCheck.IsGenericType && typeToCheck.GetGenericTypeDefinition() == genericType)
    {
        return true;
    }
    else
    {
        return IsTypeDerivedFromGenericType(typeToCheck.BaseType, genericType);
    }
}