multiple-inheritance

问题 Is there a better way of having a class inherit prototype methods from another class and still be able to define new prototype methods on the class that inherits than this: var ParentConstructor = function(){ }; ParentConstructor.prototype = { test: function () { console.log("Child"); } }; var ChildConstructor = function(){ ParentConstructor.call(this) }; ChildConstructor.prototype = { test2: "child proto" }; var TempConstructor = function(){}; TempConstructor.prototype = ParentConstructor

问题 Perhaps a rather silly and newbie question but I have been struggling with keeping my QSerialPort serial; being used within the entirety of the application I am making. (Ughh this is frustrating to explain) To be more clear I have the aforementioned QSerialPort serial; established in my MainWindow.cpp , but as I transition to another form which has a different class (for example operations.cpp ) I am unsure on how to keep and use my serial.* functions. My mainwindow.cpp form is just a

问题 Edit: I'm using Python 3 (some people asked). I think this is just a syntax question, but I want to be sure there's nothing I'm missing. Notice the syntax difference in how Foo and Bar are implemented. They achieve the same thing and I want to make sure they're really doing the same thing. The output suggests that there are just two ways to do the same thing. Is that the case? Code: class X: def some_method(self): print("X.some_method called") class Y: def some_method(self): print("Y.some

问题 I have the following code: public class MyClass { public void MyMethod() { Action<Child> aFoo = a => a.Foo(); } } interface Parent1 { void Foo(); } interface Parent2 { void Foo(); } interface Child : Parent1, Parent2 { } However, the compiler tells me that I have an ambiguous call on aFoo . I tried to do Action<Child> aFoo = (A a) => a.Foo(); but it tells me that I cannot convert lambda expression to delegate type System.Action<Child> How do I resolve the error of ambiguity? 回答1: By casting

问题 I have multiple user models .. all inheriting a Base model with a custom manager models.py class BaseUser(models.Model): [...] objects = UserManager() class StaffUser(BaseUser): [...] class Customer(BaseUser): [...] managers.py from model_utils.managers import InheritanceManager class UserManager(..., InheritanceManager): [...] By inheriting the InheritanceManager from django-model-utils, I can do automatic downcasting for inherited models. So for example, if I have 3 objects, one of each

问题 Consider the following code: class A(object): def __init__(self): print("A.__init__") super(A, self).__init__() # 1 print("A.__init__ finished") class B(A): def __init__(self): print("B.__init__") super(B, self).__init__() # 2 print("B.__init__ finished") class C(A): def __init__(self): print("C.__init__") super(C, self).__init__() print("C.__init__ finished") class D(B, C): def __init__(self): print("D.__init__") print("Initializing B") B.__init__(self) # 3 print("B initialized") print(

问题 I have a model like this: class Person(models.Model,Subject): name = .. The class Subject is not supposed to be in the Database so, it doesn't extends from models.Model: class Subject: def __init__(self,**kargs): _observers = [] my problem is that the constructor of Subject is never called , so i've tried adding this to the class Person: def __init__(self): super(Person,self).__init__() but now i have an error saying that init takes 1 arguments but 7 are given, and the only thing i'm doing is

问题 I a project of mine, written in Qt, I have a QWidget Widget that should display either a MyTreeWidget (inheriting from QTreeWidget ) or a MyTableWidget (inheriting from QTableWidget ) Constraints Widget shouldn't know who it is talking to. Therefore it must (??) own a class inherited by the My(Tree|Table)Widget MyTreeWidget and MyTableWidget share a lot of code and I don't want to copy paste this code. So I thought of making them inherit from a MyGenericView which inherit from

问题 Suppose I need to inherit from two classes in C#. This is not allowed, so I can do the following: inherit from one of the classes and include the other class as a member variable, inherit from its interfaces and reimplement all methods of those interfaces by redirecting them onto that member variable: interface SecondBaseInterface { void FirstMethod(); void SecondMethod(); }; class MyClass : FirstBaseClass, SecondBaseInterface { public void FirstMethod() { secondBase.FirstMethod(); } public

问题 UPDATE: So pretty much everyone here has told me that I just need to start all over again on how I designed my classes (thank you folks for your excellent answers by the way!). Taking the hint, I started doing extensive reading on the strategy pattern. I want to create behavior classes (or strategy classes) that inherit from an abstract base class or classes. The Candidate class would then have properties w/ the different abstract base class/classes as the Type for the behaviors or strategies