Question

如何识别（.NET 2 ）泛型类？

Class A(Of T)
End Class

' not work '
If TypeOf myObject Is A Then

Answer 1

如果是c＃就是这样：

public class A<T>
{
}

A<int> a = new A<int>();

if (a.GetType().IsGenericType && 
    a.GetType().GetGenericTypeDefinition() == typeof(A<>))
{
}

<强>已更新：

看起来这就是你真正需要的东西：

public static bool IsSubclassOf(Type childType, Type parentType)
{
    bool isParentGeneric = parentType.IsGenericType;

    return IsSubclassOf(childType, parentType, isParentGeneric);
}

private static bool IsSubclassOf(Type childType, Type parentType, bool isParentGeneric)
{
    if (childType == null)
    {
        return false;
    }

    childType = isParentGeneric && childType.IsGenericType ? childType.GetGenericTypeDefinition() : childType;

    if (childType == parentType)
    {
        return true;
    }

    return IsSubclassOf(childType.BaseType, parentType, isParentGeneric);
}

可以像这样使用：

public class A<T>
{
}

public class B : A<int>
{

}

B b = new B();
bool isSubclass = IsSubclassOf(b.GetType(), typeof (A<>)); // returns true;

Answer 2

  Public Function IsSubclassOf(ByVal childType As Type, ByVal parentType As Type) As Boolean
    Dim isParentGeneric As Boolean = parentType.IsGenericType

    Return IsSubclassOf(childType, parentType, isParentGeneric)
  End Function

  Private Function IsSubclassOf(ByVal childType As Type, ByVal parentType As Type, ByVal isParentGeneric As Boolean) As Boolean
    If childType Is Nothing Then
      Return False
    End If

    If isParentGeneric AndAlso childType.IsGenericType Then
      childType = childType.GetGenericTypeDefinition()
    End If

    If childType Is parentType Then
      Return True
    End If

    Return IsSubclassOf(childType.BaseType, parentType, isParentGeneric)
  End Function

我如何识别泛型类？

2 个答案: