这是我的实现：
FindAssignableWith、FindBaseClassWith 和 FindInterfaceWith 实现
// provide common base class or implemented interface
public static Type FindAssignableWith(this Type typeLeft, Type typeRight)
{
if(typeLeft == null || typeRight == null) return null;
var commonBaseClass = typeLeft.FindBaseClassWith(typeRight) ?? typeof(object);
return commonBaseClass.Equals(typeof(object))
? typeLeft.FindInterfaceWith(typeRight)
: commonBaseClass;
}
// searching for common base class (either concrete or abstract)
public static Type FindBaseClassWith(this Type typeLeft, Type typeRight)
{
if(typeLeft == null || typeRight == null) return null;
return typeLeft
.GetClassHierarchy()
.Intersect(typeRight.GetClassHierarchy())
.FirstOrDefault(type => !type.IsInterface);
}
// searching for common implemented interface
// it's possible for one class to implement multiple interfaces,
// in this case return first common based interface
public static Type FindInterfaceWith(this Type typeLeft, Type typeRight)
{
if(typeLeft == null || typeRight == null) return null;
return typeLeft
.GetInterfaceHierarchy()
.Intersect(typeRight.GetInterfaceHierarchy())
.FirstOrDefault();
}
// iterate on interface hierarhy
public static IEnumerable<Type> GetInterfaceHierarchy(this Type type)
{
if(type.IsInterface) return new [] { type }.AsEnumerable();
return type
.GetInterfaces()
.OrderByDescending(current => current.GetInterfaces().Count())
.AsEnumerable();
}
// interate on class hierarhy
public static IEnumerable<Type> GetClassHierarchy(this Type type)
{
if(type == null) yield break;
Type typeInHierarchy = type;
do
{
yield return typeInHierarchy;
typeInHierarchy = typeInHierarchy.BaseType;
}
while(typeInHierarchy != null && !typeInHierarchy.IsInterface);
}
关于FindInterfaceWith实现的备注
任何实现IEnumerable 或IEnumerable<T> 的接口都会在其他接口之前被选中，我认为不正确
FindInterfaceWith 的开放式问题
c# 允许在一个类中实现多个接口，在这种情况下，FindInterfaceWith 将返回第一个接口，因为无法知道IA 或@ 哪个接口987654336@ 在下面的示例中通常更可取
接口和类层次结构
public interface IBase {}
public interface ISomething {}
public interface IDerivied: IBase {}
public interface IDeriviedRight: IDerivied {}
public interface IDeriviedLeft: IDerivied, IDisposable {}
public class AnotherDisposable: IDisposable {
public void Dispose() {
}
}
public class DeriviedLeft: IDeriviedLeft {
public void Dispose() {
}
}
public class SubDeriviedLeft: DeriviedLeft {}
public class SecondSubDeriviedLeft: DeriviedLeft {}
public class ThirdSubDeriviedLeft: DeriviedLeft, ISomething {}
public class Another {}
public class DeriviedRight: IDeriviedRight {}
测试用例
以及使用NUnit断言的一组测试用例：
FindBaseClassWith 断言示例
// FindBaseClassWith returns null if one of parameters was an interface.
// FindBaseClassWith return null if any of parameter was null.
Assert.That(typeof(DeriviedLeft).FindBaseClassWith(typeof(DeriviedLeft)), Is.EqualTo(typeof(DeriviedLeft)));
FindInterfaceWith 断言示例
// FindInterfaceWith returns null if they don't have common implemented interface.
// FindBaseClassWith return null if any of parameter was null.
Assert.That(typeof(DeriviedLeft).FindInterfaceWith(typeof(DeriviedLeft)), Is.EqualTo(typeof(IDeriviedLeft)));
FinAssignableWith 断言示例
Assert.That(typeof(DeriviedLeft).FindAssignableWith(typeof(DeriviedLeft)), Is.SameAs(typeof(DeriviedLeft)));
CodeReview 讨论
Review of this answer at codereview.stackexchange.com
ps：
提供完整资源 [here]