How Can I Determine if a Type Inherits from a Generic Base Class in C#?

Detect whether a type in C# inherits from a generic base class

In programming, it is often necessary to determine the relationships between classes (especially when inheritance is involved). However, when dealing with generic classes with type parameters, validating inheritance via standard methods can be difficult.

Question:

Suppose you have the following generic and derived classes:

public class GenericClass<T> : GenericInterface<T>
{
}

public class Test : GenericClass<SomeType>
{
}

You want to check whether a given Type object (e.g., typeof(Test)) represents a type inherited from GenericClass. However, using typeof(Test).IsSubclassOf(typeof(GenericClass)) fails because it doesn't take the generic type parameters into account.

Solution:

To solve this problem, you can use the following code to determine whether the type is derived from the generic base class:

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;
}

This method determines whether toCheck directly or indirectly inherits from generic by walking the inheritance chain and comparing the base types. It handles non-generic and generic types by checking for the presence of the IsGenericType attribute and retrieving the definition of the generic type.

With this approach you can accurately determine whether a type is derived from a generic base class, regardless of the type parameters specified.

Usage example:

bool result = IsSubclassOfRawGeneric(typeof(GenericClass<>), typeof(Test)); // result will be true

The above is the detailed content of How Can I Determine if a Type Inherits from a Generic Base Class in C#?. For more information, please follow other related articles on the PHP Chinese website!