我有一个泛型类在我的项目与派生类。
public class GenericClass<T> : GenericInterface<T>
{
}
public class Test : GenericClass<SomeType>
{
}
是否有任何方法可以查明Type对象是否派生自GenericClass?
t.IsSubclassOf(typeof(GenericClass<>))
不管用。
当前回答
在fir3rpho3nixx和David Schmitt的出色回答的基础上，我修改了他们的代码，并添加了ShouldInheritOrImplementTypedGenericInterface测试(最后一个)。
/// <summary>
/// Find out if a child type implements or inherits from the parent type.
/// The parent type can be an interface or a concrete class, generic or non-generic.
/// </summary>
/// <param name="child"></param>
/// <param name="parent"></param>
/// <returns></returns>
public static bool InheritsOrImplements(this Type child, Type parent)
{
var currentChild = parent.IsGenericTypeDefinition && child.IsGenericType ? child.GetGenericTypeDefinition() : child;
while (currentChild != typeof(object))
{
if (parent == currentChild || HasAnyInterfaces(parent, currentChild))
return true;
currentChild = currentChild.BaseType != null && parent.IsGenericTypeDefinition && 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 = parent.IsGenericTypeDefinition && childInterface.IsGenericType
? childInterface.GetGenericTypeDefinition()
: childInterface;
return currentInterface == parent;
});
}
[Test]
public void ShouldInheritOrImplementNonGenericInterface()
{
Assert.That(typeof(FooImplementor)
.InheritsOrImplements(typeof(IFooInterface)), Is.True);
}
[Test]
public void ShouldInheritOrImplementGenericInterface()
{
Assert.That(typeof(GenericFooBase)
.InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}
[Test]
public void ShouldInheritOrImplementGenericInterfaceByGenericSubclass()
{
Assert.That(typeof(GenericFooImplementor<>)
.InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}
[Test]
public void ShouldInheritOrImplementGenericInterfaceByGenericSubclassNotCaringAboutGenericTypeParameter()
{
Assert.That(new GenericFooImplementor<string>().GetType()
.InheritsOrImplements(typeof(IGenericFooInterface<>)), Is.True);
}
[Test]
public void ShouldNotInheritOrImplementGenericInterfaceByGenericSubclassNotCaringAboutGenericTypeParameter()
{
Assert.That(new GenericFooImplementor<string>().GetType()
.InheritsOrImplements(typeof(IGenericFooInterface<int>)), Is.False);
}
[Test]
public void ShouldInheritOrImplementNonGenericClass()
{
Assert.That(typeof(FooImplementor)
.InheritsOrImplements(typeof(FooBase)), Is.True);
}
[Test]
public void ShouldInheritOrImplementAnyBaseType()
{
Assert.That(typeof(GenericFooImplementor<>)
.InheritsOrImplements(typeof(FooBase)), Is.True);
}
[Test]
public void ShouldInheritOrImplementTypedGenericInterface()
{
GenericFooImplementor<int> obj = new GenericFooImplementor<int>();
Type t = obj.GetType();
Assert.IsTrue(t.InheritsOrImplements(typeof(IGenericFooInterface<int>)));
Assert.IsFalse(t.InheritsOrImplements(typeof(IGenericFooInterface<String>)));
}
其他回答
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
在我看来，这个实现在更多的情况下工作(泛型类和接口有或没有初始参数，不管子和参数的数量):
public static class ReflexionExtension
{
public static bool IsSubClassOfGeneric(this Type child, Type parent)
{
if (child == parent)
return false;
if (child.IsSubclassOf(parent))
return true;
var parameters = parent.GetGenericArguments();
var isParameterLessGeneric = !(parameters != null && parameters.Length > 0 &&
((parameters[0].Attributes & TypeAttributes.BeforeFieldInit) == TypeAttributes.BeforeFieldInit));
while (child != null && child != typeof(object))
{
var cur = GetFullTypeDefinition(child);
if (parent == cur || (isParameterLessGeneric && cur.GetInterfaces().Select(i => GetFullTypeDefinition(i)).Contains(GetFullTypeDefinition(parent))))
return true;
else if (!isParameterLessGeneric)
if (GetFullTypeDefinition(parent) == cur && !cur.IsInterface)
{
if (VerifyGenericArguments(GetFullTypeDefinition(parent), cur))
if (VerifyGenericArguments(parent, child))
return true;
}
else
foreach (var item in child.GetInterfaces().Where(i => GetFullTypeDefinition(parent) == GetFullTypeDefinition(i)))
if (VerifyGenericArguments(parent, item))
return true;
child = child.BaseType;
}
return false;
}
private static Type GetFullTypeDefinition(Type type)
{
return type.IsGenericType ? type.GetGenericTypeDefinition() : type;
}
private static bool VerifyGenericArguments(Type parent, Type child)
{
Type[] childArguments = child.GetGenericArguments();
Type[] parentArguments = parent.GetGenericArguments();
if (childArguments.Length == parentArguments.Length)
for (int i = 0; i < childArguments.Length; i++)
if (childArguments[i].Assembly != parentArguments[i].Assembly || childArguments[i].Name != parentArguments[i].Name || childArguments[i].Namespace != parentArguments[i].Namespace)
if (!childArguments[i].IsSubclassOf(parentArguments[i]))
return false;
return true;
}
}
以下是我的7076个测试用例:
[TestMethod]
public void IsSubClassOfGenericTest()
{
Assert.IsTrue(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(BaseGeneric<>)), " 1");
Assert.IsFalse(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(WrongBaseGeneric<>)), " 2");
Assert.IsTrue(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), " 3");
Assert.IsFalse(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(IWrongBaseGeneric<>)), " 4");
Assert.IsTrue(typeof(IChildGeneric).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), " 5");
Assert.IsFalse(typeof(IWrongBaseGeneric<>).IsSubClassOfGeneric(typeof(ChildGeneric2<>)), " 6");
Assert.IsTrue(typeof(ChildGeneric2<>).IsSubClassOfGeneric(typeof(BaseGeneric<>)), " 7");
Assert.IsTrue(typeof(ChildGeneric2<Class1>).IsSubClassOfGeneric(typeof(BaseGeneric<>)), " 8");
Assert.IsTrue(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(BaseGeneric<Class1>)), " 9");
Assert.IsFalse(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(WrongBaseGeneric<Class1>)), "10");
Assert.IsTrue(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "11");
Assert.IsFalse(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(IWrongBaseGeneric<Class1>)), "12");
Assert.IsTrue(typeof(IChildGeneric).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "13");
Assert.IsFalse(typeof(BaseGeneric<Class1>).IsSubClassOfGeneric(typeof(ChildGeneric2<Class1>)), "14");
Assert.IsTrue(typeof(ChildGeneric2<Class1>).IsSubClassOfGeneric(typeof(BaseGeneric<Class1>)), "15");
Assert.IsFalse(typeof(ChildGeneric).IsSubClassOfGeneric(typeof(ChildGeneric)), "16");
Assert.IsFalse(typeof(IChildGeneric).IsSubClassOfGeneric(typeof(IChildGeneric)), "17");
Assert.IsFalse(typeof(IBaseGeneric<>).IsSubClassOfGeneric(typeof(IChildGeneric2<>)), "18");
Assert.IsTrue(typeof(IChildGeneric2<>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "19");
Assert.IsTrue(typeof(IChildGeneric2<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "20");
Assert.IsFalse(typeof(IBaseGeneric<Class1>).IsSubClassOfGeneric(typeof(IChildGeneric2<Class1>)), "21");
Assert.IsTrue(typeof(IChildGeneric2<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "22");
Assert.IsFalse(typeof(IBaseGeneric<Class1>).IsSubClassOfGeneric(typeof(BaseGeneric<Class1>)), "23");
Assert.IsTrue(typeof(BaseGeneric<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "24");
Assert.IsFalse(typeof(IBaseGeneric<>).IsSubClassOfGeneric(typeof(BaseGeneric<>)), "25");
Assert.IsTrue(typeof(BaseGeneric<>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "26");
Assert.IsTrue(typeof(BaseGeneric<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "27");
Assert.IsFalse(typeof(IBaseGeneric<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "28");
Assert.IsTrue(typeof(BaseGeneric2<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<Class1>)), "29");
Assert.IsFalse(typeof(IBaseGeneric<>).IsSubClassOfGeneric(typeof(BaseGeneric2<>)), "30");
Assert.IsTrue(typeof(BaseGeneric2<>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "31");
Assert.IsTrue(typeof(BaseGeneric2<Class1>).IsSubClassOfGeneric(typeof(IBaseGeneric<>)), "32");
Assert.IsTrue(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(BaseGenericA<,>)), "33");
Assert.IsFalse(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(WrongBaseGenericA<,>)), "34");
Assert.IsTrue(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "35");
Assert.IsFalse(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(IWrongBaseGenericA<,>)), "36");
Assert.IsTrue(typeof(IChildGenericA).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "37");
Assert.IsFalse(typeof(IWrongBaseGenericA<,>).IsSubClassOfGeneric(typeof(ChildGenericA2<,>)), "38");
Assert.IsTrue(typeof(ChildGenericA2<,>).IsSubClassOfGeneric(typeof(BaseGenericA<,>)), "39");
Assert.IsTrue(typeof(ChildGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(BaseGenericA<,>)), "40");
Assert.IsTrue(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(BaseGenericA<ClassA, ClassB>)), "41");
Assert.IsFalse(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(WrongBaseGenericA<ClassA, ClassB>)), "42");
Assert.IsTrue(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "43");
Assert.IsFalse(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(IWrongBaseGenericA<ClassA, ClassB>)), "44");
Assert.IsTrue(typeof(IChildGenericA).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "45");
Assert.IsFalse(typeof(BaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(ChildGenericA2<ClassA, ClassB>)), "46");
Assert.IsTrue(typeof(ChildGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(BaseGenericA<ClassA, ClassB>)), "47");
Assert.IsFalse(typeof(ChildGenericA).IsSubClassOfGeneric(typeof(ChildGenericA)), "48");
Assert.IsFalse(typeof(IChildGenericA).IsSubClassOfGeneric(typeof(IChildGenericA)), "49");
Assert.IsFalse(typeof(IBaseGenericA<,>).IsSubClassOfGeneric(typeof(IChildGenericA2<,>)), "50");
Assert.IsTrue(typeof(IChildGenericA2<,>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "51");
Assert.IsTrue(typeof(IChildGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "52");
Assert.IsFalse(typeof(IBaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IChildGenericA2<ClassA, ClassB>)), "53");
Assert.IsTrue(typeof(IChildGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "54");
Assert.IsFalse(typeof(IBaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(BaseGenericA<ClassA, ClassB>)), "55");
Assert.IsTrue(typeof(BaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "56");
Assert.IsFalse(typeof(IBaseGenericA<,>).IsSubClassOfGeneric(typeof(BaseGenericA<,>)), "57");
Assert.IsTrue(typeof(BaseGenericA<,>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "58");
Assert.IsTrue(typeof(BaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "59");
Assert.IsFalse(typeof(IBaseGenericA<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "60");
Assert.IsTrue(typeof(BaseGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "61");
Assert.IsFalse(typeof(IBaseGenericA<,>).IsSubClassOfGeneric(typeof(BaseGenericA2<,>)), "62");
Assert.IsTrue(typeof(BaseGenericA2<,>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "63");
Assert.IsTrue(typeof(BaseGenericA2<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericA<,>)), "64");
Assert.IsFalse(typeof(BaseGenericA2<ClassB, ClassA>).IsSubClassOfGeneric(typeof(IBaseGenericA<ClassA, ClassB>)), "65");
Assert.IsFalse(typeof(BaseGenericA<ClassB, ClassA>).IsSubClassOfGeneric(typeof(ChildGenericA2<ClassA, ClassB>)), "66");
Assert.IsFalse(typeof(BaseGenericA2<ClassB, ClassA>).IsSubClassOfGeneric(typeof(BaseGenericA<ClassA, ClassB>)), "67");
Assert.IsTrue(typeof(ChildGenericA3<ClassA, ClassB>).IsSubClassOfGeneric(typeof(BaseGenericB<ClassA, ClassB, ClassC>)), "68");
Assert.IsTrue(typeof(ChildGenericA4<ClassA, ClassB>).IsSubClassOfGeneric(typeof(IBaseGenericB<ClassA, ClassB, ClassC>)), "69");
Assert.IsFalse(typeof(ChildGenericA3<ClassB, ClassA>).IsSubClassOfGeneric(typeof(BaseGenericB<ClassA, ClassB, ClassC>)), "68-2");
Assert.IsTrue(typeof(ChildGenericA3<ClassA, ClassB2>).IsSubClassOfGeneric(typeof(BaseGenericB<ClassA, ClassB, ClassC>)), "68-3");
Assert.IsFalse(typeof(ChildGenericA3<ClassB2, ClassA>).IsSubClassOfGeneric(typeof(BaseGenericB<ClassA, ClassB, ClassC>)), "68-4");
Assert.IsFalse(typeof(ChildGenericA4<ClassB, ClassA>).IsSubClassOfGeneric(typeof(IBaseGenericB<ClassA, ClassB, ClassC>)), "69-2");
Assert.IsTrue(typeof(ChildGenericA4<ClassA, ClassB2>).IsSubClassOfGeneric(typeof(IBaseGenericB<ClassA, ClassB, ClassC>)), "69-3");
Assert.IsFalse(typeof(ChildGenericA4<ClassB2, ClassA>).IsSubClassOfGeneric(typeof(IBaseGenericB<ClassA, ClassB, ClassC>)), "69-4");
Assert.IsFalse(typeof(bool).IsSubClassOfGeneric(typeof(IBaseGenericB<ClassA, ClassB, ClassC>)), "70");
}
用于测试的类和接口:
public class Class1 { }
public class BaseGeneric<T> : IBaseGeneric<T> { }
public class BaseGeneric2<T> : IBaseGeneric<T>, IInterfaceBidon { }
public interface IBaseGeneric<T> { }
public class ChildGeneric : BaseGeneric<Class1> { }
public interface IChildGeneric : IBaseGeneric<Class1> { }
public class ChildGeneric2<Class1> : BaseGeneric<Class1> { }
public interface IChildGeneric2<Class1> : IBaseGeneric<Class1> { }
public class WrongBaseGeneric<T> { }
public interface IWrongBaseGeneric<T> { }
public interface IInterfaceBidon { }
public class ClassA { }
public class ClassB { }
public class ClassC { }
public class ClassB2 : ClassB { }
public class BaseGenericA<T, U> : IBaseGenericA<T, U> { }
public class BaseGenericB<T, U, V> { }
public interface IBaseGenericB<ClassA, ClassB, ClassC> { }
public class BaseGenericA2<T, U> : IBaseGenericA<T, U>, IInterfaceBidonA { }
public interface IBaseGenericA<T, U> { }
public class ChildGenericA : BaseGenericA<ClassA, ClassB> { }
public interface IChildGenericA : IBaseGenericA<ClassA, ClassB> { }
public class ChildGenericA2<ClassA, ClassB> : BaseGenericA<ClassA, ClassB> { }
public class ChildGenericA3<ClassA, ClassB> : BaseGenericB<ClassA, ClassB, ClassC> { }
public class ChildGenericA4<ClassA, ClassB> : IBaseGenericB<ClassA, ClassB, ClassC> { }
public interface IChildGenericA2<ClassA, ClassB> : IBaseGenericA<ClassA, ClassB> { }
public class WrongBaseGenericA<T, U> { }
public interface IWrongBaseGenericA<T, U> { }
public interface IInterfaceBidonA { }
这些都可以用linq轻松完成。这将找到泛型基类GenericBaseType的子类的任何类型。
IEnumerable<Type> allTypes = Assembly.GetExecutingAssembly().GetTypes();
IEnumerable<Type> mySubclasses = allTypes.Where(t => t.BaseType != null
&& t.BaseType.IsGenericType
&& t.BaseType.GetGenericTypeDefinition() == typeof(GenericBaseType<,>));
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;
}
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
