Given a C# Type, Get its Base Classes and Implemented Interfaces

Question

I\'m working on a game engine in C#. The class I\'m working on is called CEntityRegistry, and its job is to keep track of the many instances of CEntity

Answer 1

Use this code:

Func<Type, List<Type>> f = ty =>
{
    var tysReturn = new List<Type>();
    if (ty.BaseType != null)
    {
        tysReturn.Add(ty.BaseType);
    }
    tysReturn.AddRange(ty.GetInterfaces());
    return tysReturn;
};

The function f will take a Type and return a list of its base type plus interfaces.

Hope it helps.

Answer 2

More refined answer based on one from SLaks would be:

public static IEnumerable<Type> GetBaseClassesAndInterfaces(this Type type)
{
    return type.BaseType == typeof(object) 
        ? type.GetInterfaces()
        : Enumerable
            .Repeat(type.BaseType, 1)
            .Concat(type.GetInterfaces())
            .Concat(type.BaseType.GetBaseClassesAndInterfaces())
            .Distinct();
}

Answer 3

You could write an extension method like this:

public static IEnumerable<Type> GetBaseTypes(this Type type) {
    if(type.BaseType == null) return type.GetInterfaces();

    return Enumerable.Repeat(type.BaseType, 1)
                     .Concat(type.GetInterfaces())
                     .Concat(type.GetInterfaces().SelectMany<Type, Type>(GetBaseTypes))
                     .Concat(type.BaseType.GetBaseTypes());
}

Answer 4

Here. The previous answers have problems. Also, this answer doesn't need "Distinct". The values are already distinct. And this one is more efficient.

    public static IEnumerable<Type> GetBaseTypes(this Type type, bool bIncludeInterfaces = false)
    {
        if (type == null)
            yield break;

        for (var nextType = type.BaseType; nextType != null; nextType = nextType.BaseType)
            yield return nextType;

        if (!bIncludeInterfaces)
            yield break;

        foreach (var i in type.GetInterfaces())
            yield return i;
    }

Answer 5

Type has a property BaseType and a method FindInterfaces.

https://msdn.microsoft.com/en-us/library/system.type.aspx

So actually, it almost does have Type.GetAllBaseClassesAndInterfaces, but you have to make two calls instead of one.