inheritance

问题 i have a struct in user package called account type Account struct { Tp string `json:"type"bson:"type"` AccountId string `json:"account_id"bson:"account_id"` Credentials map[string]interface{} `json:"credentials,omitempty"bson:"credentials,omitempty"` ProfilePicture string `json:"profile_picture,omitempty"` Username string `json:"username"bson:"username"` AccessToken map[string]interface{}`bson:"access_token,omitempty"` } and in user/accounts im trying to embed this account struct into

问题 hoping a grandmaster can shed some light. Very high overview is that I am no beginner to coding, but still new to OOP. This set of message classes is at the heart of a large simulation application we're writing, and I don't want to do it stupidly--this interface cuts the application in half, from sequencer to executer and vice-versa. My question is whether or not it's a bad idea to have an inheritance hierarchy this deep (image is not yet fleshed out, might go 5 or 6 deep in the end). This is

问题 The select field can be found here: in the Material-UI demo It's methods appear to be inherited from the menu / popover classes but I haven't been able to figure out how to fire 'open' when onFocus event fires for example. This would solve my keyboard related usability issues! 回答1: You could do it by accessing the DOM node of the down arrow button, and manually triggering a click event on it. Example that works on Mac Chrome on the demo website, via the console, after adding a 'mySelect' id

问题 Can anyone tell me how the implicit inheritance works in java internally? What I mean is if I create a class how exactly it extends the Object class in the JVM? Thanks in advance. 回答1: Java forces inheritance on every class. If you do not explicitly inherit from a class, then by default Java assumes that you are inheriting from the class called Object, which does not do much, but does have several useful methods : it implies that every class is descended from Object, since whatever class you

问题 What is the difference (if any) between these two F# type signatures? UseTheStream<'a when 'a :> Stream> : 'a -> unit and UseTheStream : (stream : Stream) -> unit Do they mean the same thing in this case? msdn says the following about the (:>) Type Constraint type-parameter :> type -- The provided type must be equal to or derived from the type specified, or, if the type is an interface, the provided type must implement the interface. This would indicate that the two signatures are saying the

问题 I recently came across this question. import Object class Visitor(Object): def __init__(self): super(Visitor,self).__init__() def visit(self, obj): pass def getIsDone(self): return False isDone = property(fget =lambda self:self.getIsDone()) I get this error: TypeError: module.__init__() takes at most 2 arguments (3 given) and its answer: class A:pass print(A) #outputs <class '__main__.A'> import urllib print(urllib) #outputs <module 'urllib' from '/usr/lib/python3.2/urllib/__init__.py'> Your

问题 I'm creating a UserControl that's a specialized ListBox/View (type not relevant). Now I'm faced with the option to either keep the type as UserControl or Inherit the List control. 1) If I keep it as a UserControl I have a List control inside it and then I have to create a DP for ItemsSource and so on. 2) Let it inherit List control and thus it automatically exposes ItemsSource property. Is either way acceptable or will it become some Code Horror. What is expected. Is there maybe a option 3 I

问题 Is it possible to specify alignment of parent class? for example something like (which does not compiled): template<size_t n> class Vector : public boost::array<double,n> __attribute__ ((aligned(16))) { thanks well, from comments I gather this is no good way to go. I think I will just stick to composition/alignment of private array 回答1: We don't need to request alignment on the derived class neither we can. The reason why we don't need is that it is enough to request alignment for the derived

问题 Is it possible to specify alignment of parent class? for example something like (which does not compiled): template<size_t n> class Vector : public boost::array<double,n> __attribute__ ((aligned(16))) { thanks well, from comments I gather this is no good way to go. I think I will just stick to composition/alignment of private array 回答1: We don't need to request alignment on the derived class neither we can. The reason why we don't need is that it is enough to request alignment for the derived

问题 I have a service returning an array of type Party. Party has two subtypes, Person and Organization. I’m consuming this service in my WPF application (Prism, MVVM) from a view model. In the constructor of this view model I populate an observable collection of type Party: public PhoneBookViewModel(IPhoneBookService phoneBookProxy) { _phoneBookProxy = phoneBookProxy; var parties = _phoneBookProxy.GetAllParties(); _parties = new ObservableCollection<Party>(parties.ToList()); } So far so good. In