inheritance

问题 It should be possible to use generics here and pass the class-type of the Model. However this is not accepted by Visual Studio 2008: <%@ Page Inherits="System.Web.Mvc.ViewPage(of IEnumerable(of MyNamespace.MyClass))" %> I get the following validation-error (underlined in VS): 'Context' is not a member of 'ASP._views___home___index__asp' I get the following runtime error: BC30456: 'InitializeCulture' is not a member of 'ASP._views___home___index__asp'. Note, I am using Visual Basic.NET - but

问题 Consider the following code: struct A { virtual void f() = 0; }; struct B { void f(); }; struct C : public A, public B {}; int main() { A* a = new C(); B* b = new C(); C* c = new C(); // All these calls should result in B::f a->f(); b->f(); c->f(); } The compiler states that C is abstract. How can this situation be resolved? The issue seems similar to diamond inheritance, but I fail to see the solution. EDIT: Thanks, this is the working example: #include "stdio.h" struct A { virtual void f()

问题 I would like to force SubClasses to @Override method from SuperClass . Method in SuperClass can't be abstract , cause I wanna provide some basic implementation. Here is example of my code: public abstract class GenericModel<T extends GenericModel> { long id, counter; public String methodToBeOverridenInSubClass(String name) { // some basic implementation // rest details will be provided by subclass return name; } } public class SubClass extends GenericModel<SubClass> { @Override public String

问题 I want to inherit the DevExpress ComboBoxEdit control, and am wondering if naming my class the same as the DevExpress class is bad practice. Here's the derived class declaration: using System; using System.Collections.Generic; using System.Text; namespace MyApplication.Components { public class ComboBoxEdit : DevExpress.XtraEditors.ComboBoxEdit { } } Should I rename MyApplication.Components.ComboBoxEdit to something else like MyComboBoxEdit? 回答1: There's must be a reason why you're creating

问题 If I have a parent class and a child class, I want list of all the attributes which are defined in child class but not inherited from parent class. Note: I know I can get the list of all the attributes from parent class and get all the attributes from child class and take intersection, but this does not work in my scenario. 回答1: You can use the fact, that the address of the attribute is not the same (equal) to the one inherited. See example: from __future__ import print_function class A: def

问题 If I have a parent class and a child class, I want list of all the attributes which are defined in child class but not inherited from parent class. Note: I know I can get the list of all the attributes from parent class and get all the attributes from child class and take intersection, but this does not work in my scenario. 回答1: You can use the fact, that the address of the attribute is not the same (equal) to the one inherited. See example: from __future__ import print_function class A: def

问题 I understand that whenever you have a polymorphic base class, the base class should define a virtual destructor. So that when a base-class pointer to a derived-class object is deleted, it will call the destructor of the derived class first. Correct me if i am wrong here. also, if the base-class destructor were to be non-virtual, it would be undefined behavior to delete a baseclass pointer to a derived object. Correct me if i am wrong aswell. so my question is: Why is it exactly, that when the

问题 I understand that whenever you have a polymorphic base class, the base class should define a virtual destructor. So that when a base-class pointer to a derived-class object is deleted, it will call the destructor of the derived class first. Correct me if i am wrong here. also, if the base-class destructor were to be non-virtual, it would be undefined behavior to delete a baseclass pointer to a derived object. Correct me if i am wrong aswell. so my question is: Why is it exactly, that when the

问题 I understand that whenever you have a polymorphic base class, the base class should define a virtual destructor. So that when a base-class pointer to a derived-class object is deleted, it will call the destructor of the derived class first. Correct me if i am wrong here. also, if the base-class destructor were to be non-virtual, it would be undefined behavior to delete a baseclass pointer to a derived object. Correct me if i am wrong aswell. so my question is: Why is it exactly, that when the

问题 I'm a Python newbie, trying to understand the philosophy/logic behind the inheritance methods. Questions ultimately regards why and when one has to use the __init__ method in a subclass. Example: It seems a subclass inheriting from a superclass need not have its own constructor (__init__ ) method. Below, a dog inherits the attributes (name, age) and methods (makenoise) of a mammal. You can even add a method ( do_a_trick ) Everything works as it ``should", it seems. However, if I wanted to add