multiple-inheritance

问题 I think that there's a solution to my inheritance problem but I can't find it. I'm developing an Android application (target is Android 2.1) which reuses a SlidingDrawer (for my menu) on most of the pages. In order to avoid to initialize it on all the Activity I created a DefaultActivity to do so. It worked well until I had to extends TabActivity because Java doesn't support multiple inheritance. Basically I have the following Default activity public class DefaultActivity extends Activity{ //

问题 I'm looking at this data model I've come up with and not feeling comfortable. I've changed the entity names so it (hopefully) makes more sense. In any event, how would you model the following? I have 3 entities. GovernmentCustomer, PrivateCustomer, PublicCustomer. Private and Public Customer are both CorporateCustomers. Corporate and Government Customers are Accounts. All Accounts share the same key space (So if PrivateCustomer has a PK of 1 it shouldn't be possible for Public or

问题 I show an example of what I mean which, is easier. Imagine the generic type C means Color type: So for visual simplification assume C is C extends Color interface Screen { <C> Background<C> render(Plane<C> plane); } interface MonochromeScreen<C> extends Screen{ @Override Background<C> render(Plane<C> plane); } This would throw a name clash compilation error explaining that both have the same type erasure but are not overridable. But I cannot understand why we could not simply allow overriding

问题 I am trying to do something I haven't really done before. I basically have 3 classes. Class A is an abstract class with pure virtual methods, Class B is a class on it's own that contains methods with the same name as the virtual methods in Class A. I'm trying to tie everything together in Class C. I'd like to inherit class B and A in C (multiple inheritance), and use the methods from Class B to implement those in class A. This way I create a modular approach. The example below is a very

问题 I have used faking of multiple inheritance as given in Can I extend a class using more than 1 class in PHP? Notice that class A actually extends class B and faking is done for extending from class C. It was working fine until I needed an attribute set in a function of class C to be available in class A. Consider a little edited version of that code where I call a function of class C from inside a function of class A :- //Class A class A extends B { private $c; public function __construct() {

问题 I have a class Journey which I want to make a superclass and another class plannedjourney. The plannedjourney class extends JFrame since it contains forms..However I also want this class to extends Journey.. Is there a possible way to do this? 回答1: Don't mix models and views. If you keep both domains clearly separated, then you won't be in need of multiple inheritance (this time). You have one model class for journeys and a viewer for such journeys. The viewer should subclass Component and be

问题 I know the diamond problem and method to solve it using virtual base class. I tried to solve diamond problem in a different way but did not succeed. I don't know why. #include <iostream> using namespace std; class A { public: void display() { cout << "successfully printed"; } }; class B: public A { }; class C: private A // display() of A will become private member of C { }; class D: public B, public C // private member display() of C should not be inherited { }; int main() { D d; d.display();

问题 I have to create a Course Management System with course categories: Cooking, sewing and writing courses cooking and writing each have 2 courses (Italian, seafood, creative write and business write). This creates derived abstract: abstract course -> abstract cooking -> concrete seafood The abstract cooking and writing have common fields and some common methods, however they also have abstract methods that are abstract in the base class. Can this be done in C#? If I make the derived abstract

问题 I was looking into Python's super method and multiple inheritance. I read along something like when we use super to call a base method which has implementation in all base classes, only one class' method will be called even with variety of arguments. For example, class Base1(object): def __init__(self, a): print "In Base 1" class Base2(object): def __init__(self): print "In Base 2" class Child(Base1, Base2): def __init__(self): super(Child, self).__init__('Intended for base 1') super(Child,

问题 I'm facing a problem regarding multiple inheritance in VB.net: As far as I know VB.net does not support multiple inheritance in general but you can reach a kind of multiple inheritance by working with interfaces (using “Implements” instead of “Inherits”): Public Class ClassName Implements BaseInterface1, BaseInterface2 End Class That works fine for classes but I’d like to have an interface inheriting some base interfaces. Something like that: Public Interface InterfaceName Implements