inheritance

问题 In ObjC, how do I hide implementation a superclass's methods in a subclass? I'm not sure if @private would do the trick, as it appears to only apply to ivars. 回答1: There are no actually "private" methods in Obj-C; since any message can be sent to any object at runtime, there's no way to prevent someone from sending the message you care about. That said, you can intercept that message in the subclass and not handle it. The simplest way to make a superclass's method inaccessible is to override

问题 ObjectPropertyBase skips value invalidation when newValue == oldValue : /** * {@inheritDoc} */ @Override public void set(T newValue) { if (isBound()) { throw new java.lang.RuntimeException((getBean() != null && getName() != null ? getBean().getClass().getSimpleName() + "." + getName() + " : ": "") + "A bound value cannot be set."); } if (value != newValue) { value = newValue; markInvalid(); } } Problem: markInvalid() and value are private , therefore I cannot override set(newValue) properly.

问题 This is a follow-up question to a previous question. From what I understand, one @Controller -annotated class with @RequestMapping -annotated methods cannot successfully inherit from another because Spring can't recognize they're both mapping to the same method(s). Even if Spring recognized they were the same instance, it would have no way to decide which instance of the two controller beans to use to invoke the method. But static methods are invoked independent of any instances of a class,

问题 I am using the Entity Framework and have an inheritance structure with a base Entity (let's call it Customer) and a derived Entity, let's call it AccountCustomer. The difference is that an AccountCustomer has extra details (such as payment terms etc.) stored in a separate table in the database and therefore extra properties in the Entity. I want to allow users to 'promote' a specific Customer to be an AccountCustomer. I need to keep the same primary key (a composite key visible to users and

问题 ORIGINAL POST When compiled, the following code produces error C2436: '__ctor' : member function or nested class in constructor initializer list in Child.h #include Parent.h class Child : public Parent { public: Child (List* pList) : Parent::Parent(pList) { } }; Here the parent class: in Parent.h class __declspec(dllimport) Parent : public GrandParent { public: Parent (List* pList = NULL); } in Parent.cpp Parent::Parent (List* pList) : m_a(1) ,m_b(1) ,GrandParent(pList) { } Isn't it right the

问题 I'm so lost. I know how to use caller to get the caller method, but what do you use the get the caller class? For example: class Testing def return_caller_class return caller_class end end class Parent attr_accessor :test_me def initialize self.test_me = Testing.new end end class Child < Parent end class GrandChild < Child end test_Parent = Parent.new test_Child = Child.new test_GrandChild = GrandChild.new puts test_Parent.test_me.return_caller_class => Parent puts test_Child.test_me.return

问题 I want to add some functionality to ITask/TTask. I wrapped the new methods in a new Interface (IMyTask) which inherits from ITask: type IMyTask = interface(ITask) procedure MyNewMethod; end; TMyTask = class(TTask, ITask, IMyTask) private FSomeList: TList<integer>; public procedure MyNewMethod; constructor Create(const AProc: TProc; AThreadPool: TThreadPool = nil); overload; constructor Create(Sender: TObject; Event: TNotifyEvent); overload; constructor Create(const Proc: TProc); overload;

问题 This question already has answers here : typescript - cloning object (19 answers) Closed 3 years ago . I want to create new instance of Child class from Base class method. It's a little bit complicated, but i will try to explain. Here's an example: class Base(){ constructor(){} clone(){ //Here i want to create new instance } } class Child extends Base(){} var bar = new Child(); var cloned = bar.clone(); clone instanceof Child //should be true! So. From this example i want to clone my bar

问题 This question already has answers here : typescript - cloning object (19 answers) Closed 3 years ago . I want to create new instance of Child class from Base class method. It's a little bit complicated, but i will try to explain. Here's an example: class Base(){ constructor(){} clone(){ //Here i want to create new instance } } class Child extends Base(){} var bar = new Child(); var cloned = bar.clone(); clone instanceof Child //should be true! So. From this example i want to clone my bar

问题 I have the following situation: value = 4 class Foo(object): def __init__(self): self.d = value # I want all childs to have this attribute class Bar(Foo): def __init__(self): super(Bar, self).__init__() # instances of Bar simply inherit from Foo self.d = 12 # and have their values set at will class FaBoo(Foo): def __init__(self): super(FaBoo, self).__init__() # FaBoo does as well @property # but for FaBoo it is better to calculate d def d(self): return 2 * value C = FaBoo() # raises