GetAnyElementType

TypeExtension.cs

public static class TypeExtension
{
    /// <summary>
    /// 
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    public static Type GetAnyElementType(this Type type)
    {
        // Type is Array
        // short-circuit if you expect lots of arrays
        if (type.IsArray)
            return type.GetElementType();

        // type is IEnumerable<T>;
        if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IEnumerable<>))
            return type.GetGenericArguments()[0];

        // type implements/extends IEnumerable<T>;
        var enumType = type.GetInterfaces()
            .Where(t => t.IsGenericType && t.GetGenericTypeDefinition() == typeof(IEnumerable<>))
            .Select(t => t.GenericTypeArguments[0])
            .FirstOrDefault();

        return enumType ?? type;
    }
}