inheritance

问题 So, here is a problem: I want to define an abstract class, let's say AbstractA , which does not require subclasses to implement any of its methods, but rather to extend its functionality. In terms of Java that would be interface class. Moreover, I want to be able to create an abstract subclass, let's say AbstractB , of the AbstractA with the same properties, but some methods redefining or extending base class methods. I don't want though to make class ( AbstractA ) abstract e.g. through the

问题 One of my WCF endpoints has this method: GetData(DataTable dt) I tried to create a class on the client that inherits from the DataTable class public class ExtendedDataTable : DataTable{ //...implementation } and pass it along with the endpoint call: GetData(new ExtendedDataTable()); Then I got the SerializationException . Accordingly to the error, it suggests that I use either DataContractResolver or the KnownType attribute. I don't want to use the KnownType, because I shouldn't have to

问题 I am confused with the static binding example below. I reckon that S2.x and S2.y shows static binding as they prints out the fields according to s2 's static type. And S2.foo() makes s2 call the foo method in the super class, as foo is not over ridden in the subclass. However with S2.goo() , isn't it supposed to call the goo() method in the Test1 subclass? Like it's polymorphism? How come it's static binding? It looks like S2.goo() calls the Super Class goo() method and prints out =13 . Many

问题 I'm having a combination of "backend" together with a "type". Backends: Cloudant, ElasticSearch, File, ZODB Types: News, (potentially others) So I'm now defining classes like: Plugin PluginCloudant (which inherits from Plugin) PluginNews (which inherits from Plugin) The combined class is then: class PluginCloudantNews(PluginCloudant, PluginNews) Now, I'd like to dynamically allow people to define a Service (which takes a Plugin as an argument). The service's implementation will only rely on

问题 So I am looking at these respective classes (and subclasses)... public class Control{ public Control(){} public Control(String name, String type, ContainerControl owner){ //do stuff here } } public class ContainerControl extends Control{ public ContainerControl() { super(); } public ContainerControl(String name, String type, ContainerControl owner) { super(name, type, owner); controls = new Controls(); //exists somewhere else } } public class SSTab extends ContainerControl{ public SSTab(){

问题 I've got a peculiar request, hopefully it's not too far fetched and can be done. I've got a template class template<class T> class Packable { public: // Packs a <class T> into a Packet (Packet << T) virtual sf::Packet& operator <<(sf::Packet& p) const = 0; friend sf::Packet& operator <<(sf::Packet& p, const T &t); friend sf::Packet& operator <<(sf::Packet& p, const T *t); // Packs a Packet into a <class T> (T << Packet) virtual T operator <<(sf::Packet& p) const = 0; friend T& operator <<(T

问题 hey i saw this topic here: Can I call methods in constructor in Java? My Question is smilar, but a little bit different. I want to know whats happening, if i call from a constructor from class A something outside of that from class B with this from A. In my example below A is JobImpl , and B is that queue in Scheduler. class JobImpl implements Job { public JobImpl(Scheduler s, JobHandler runJob, boolean advancedWaitOnCancel, boolean oneShot) { this.s = s; this.runJob = runJob; this

问题 In one project I have an Editor Class: namespace TestXamlInherit234 { public class CustomerEditor : BaseEditor { public CustomerEditor() { TheMessage.Text = "changed222"; } } } which inherits from a WPF User Control in another project : using System.Windows.Controls; namespace Core { public partial class BaseEditor : UserControl { public TextBlock TheMessage { get { return TheMessage2; } } public BaseEditor() { InitializeComponent(); } } } <UserControl x:Class="Core.BaseEditor" xmlns="http:/

问题 What is the best aproach to develop a TPH based entity with Entity Framework, for example, if I have common fields in an Ads website, and specific ones: public class Ad { // Primary properties public int Id { get; set; } public string Title { get; set; } public string TitleStandard { get; set; } public string Version { get; set; } public string VersionStandard { get; set; } public int Year { get; set; } public decimal Price { get; set; } // Navigation properties public Color Color { get; set;

问题 I would like to allow the implicit conversion when summing two complex numbers std::complex<double> a; std::complex<long double> b; auto c = a+b; I tried to implement what was suggested here C++ implicit type conversion with template I defined a derived class of std::complex and I added the friend function that should allow the implicit conversion. Here is my code: template <typename T> class Complex : private std::complex<T> { friend Complex operator+ (Complex const &lhs, Complex const &rhs)