If I understand well, you have to wait for the C# 8 that will have this is called https://github.com/dotnet/csharplang/blob/master/proposals/default-interface-methods.md . If you can't wait, you'll have to implement the methods in the classes.What you can do if it's all the same implementation is to create a static class with the methods implemented, there in each class in the implementation of the method you just call the static method, passing through the parameters received, in this way is delegating the execution is no need to repeat the code, in addition to what the static method reflects in the execution of all classes. This is the same solution I had to do in Java until version 7.

I wouldn't know why they chose to do this, maybe they don't know and question the decision, but their assumption is the most obvious explanation. She has a name, her name https://pt.stackoverflow.com/q/76511/101 and it serves only to inform that certain classes can do something, but the implementation of this is not in class. It's almost always a mistake has a better choice.Particularly I prefer a custom attribute annotation, something like @Serializable. any code or external tool can "look" to the class and know that it can or won't do something, just use creativity. And precisely because it shows that it has a capacity and not having the capacity inside it should not be an interface.

You can use:container.destroy()

One fragment fragment fragment should be implemented in a way that is self-sufficient, should be able to work/follow its purpose by itself.Following this principle the fragment fragment fragment can be used by any activity. This is one of the main benefits of using fragments. For this, the call of methods of activity by fragment fragment fragment, should be made only in order to inform the activity that something has happened, and for this purpose a interface that activity should implement. O fragment fragment fragment can then check if the activity that created it implements or not interface, deciding whether or not to be created.In the first case, it does not call any of the interface methods.In the second, it makes an exception. In my fragments never use getActivity(). If I need one Context, getting it in the method onAttach(), if I need to communicate with Activity, I will implement a interface. My approach is as follows: I declare interface and two attributes in the derived class of Fragment public interface Container{ //Métodos que as actividades devem implementar } private Container container; private Context context; Method onAttach() these attributes are used to save the context and a reference to interface implemented in activity who created the fragment fragment fragment @Override public void onAttach(Activity activity) { if(activity instanceof Container){ container = (Container) activity; //Guarda uma referência à actividade(interface) } else{ throw new ClassCastException(activity.toString() + " A actividade deve implementar a interface Container"); } context = activity; //Guarda context. super.onAttach(activity); } When I need one context context use the attribute context.When I need to call a method of activity use container.nomeMetodo(); See the documentation android with regard to http://developer.android.com/guide/components/fragments.html#Design

I found it interesting and decided to write the way it would solve this issue._ and lacks some adjustments, even because some methods that seemed more obvious to me were not written, but the logica thick is here.Come on.Create a pointer variable, qte_sequence and an array to save sequencesglobal.Create a Handler that receives the messages to change the colors of the buttons:private Handler myHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case 0: volta_a_cor_normal; if ( ponteiro < qte_sequencia ) { ponteiro++; AcendeCor(ponteiro); } break; case 5: seta_a_cor_vermelha; break; case 10: seta_a_cor_amarela; break; case 15: seta_a_cor_azul; break; case 20: seta_a_cor_verde; break; default: break; } } }; Initializes objects, assigning to each the click event to light up when the player touches the button. I'm using the DebouncedOnClickListener class to avoid the double click, but you can use the one that suits you most. btn_vermelho = (Button) findViewById(R.id.btnVermelho); btn.setOnClickListener(new DebouncedOnClickListener() { @Override public void onDebouncedClick(View v) throws UnsupportedEncodingException { } myHandler.sendEmptyMessage(5); new Handler().postDelayed(new Runnable() { @Override public void run() { myHandler.sendEmptyMessage(0); } ,1000); } }); ... repeats to all others by changing what has to be changed.Create the procedure that will turn on the buttons automatically.private void AcendeCor(Integer ponteiro) { Integer botao = sequencia[ ponteiro ]; switch (botão} { 1 : { SetaBotaoAmarelo; break; } 2 : { SetaBotaoVermelho; break; } 3 : { SetaBotaoVerde; break; } 4 : { SetaBotaoAzul; break; } } new Handler().postDelayed(new Runnable() { @Override public void run() { myHandler.sendEmptyMessage(0); } ,1000); } } Let's say I'll generate a 5-color sequence for the repeat userThe sequence generated randomly was this: 1.2.2,4,3Zera the pointer and arrow variable qte_sequencia = 5I call the method AcendeCor( ponteiro )The method receives the pointer, check which button to light according with the sequence. Access and initialize the Handler. This in turn waits for 1 second and calls the myHandler that erases the button, increases the pointer and repeats the process.

That's what the error message is saying, you didn't implement the interface https://docs.oracle.com/javase/10/docs/api/java/lang/Comparable.html in its class Produto. For an object to be placed in a collection SortedSet this type needs to be able to deliver if an object of it is larger or smaller or equal to another object, after all this collection needs to be classified ( https://pt.stackoverflow.com/q/168531/101 ) and the classification requires knowing this characteristic.Then the mistake is in class Produto and not in this excerpt of code, or with the data used, should be something like (usually):class Produto implements Comparable<Produto> { ... @Override public int compareTo(Produto outro) { return String.compare(this.nome, outro.nome); } } https://github.com/maniero/SOpt/blob/master/Java/Interface/ImplmentsComparable.java .I invented a criterion, generally alphabetical of his general name will not be very good, but it may be what he wants.

It is not exactly possible, even in the newest versions of the language. It is possible in TypeScript, and https://pt.stackoverflow.com/a/308357/101 , precisely because it is more robust and complete.What you can do in JS is just adopt certain standards. You can create a class with non-implementation methods. It's far from ideal, it's not going to do what's most important in the interface that is to do a contract, but it's something similar. Have some https://hackernoon.com/implementing-interfaces-in-javascript-with-implement-js-8746838f8caa , but it's ugly. You have other ways to do this, but honestly if you really need it is time to go to TS.Apart from that I can only say that it is not part of the philosophy of language having this kind of verification. JavaScript is a dynamic, flexible typing language, never compromised with contracts.

At first there was not much change. Interfaces are usually preferred when there is no state or implementation, which is your case. And this is the most important thing to watch. This case does not demand classes. If the problem was another I would think differently. Therefore it is important never to go after good practices and analyze the specific problem. Understand what you want. For this it is important to understand the difference between the two.You could even have a future limitation using an abstract class because Java only allows "truth" inheritance of only one class. And any class that inherits from the abstract class Funcionario you cannot inherit from another class, you can only implement other interfaces.In practice I doubt that this really is a problem in most cases. If you just implement Funcionario in the described classes will allow in the future that you can inherit from some class (abstract or not) since you had only implemented interfaces and no class. But will you modify these existing classes to inherit from another class? It will hurt http://en.wikipedia.org/wiki/Open/closed_principle ? And he's usually important in these cases. I do not say that there is no situation where this can be interesting, but in general it is not.Is there any reason to prefer the abstract class? If I don't find one, I'd have the interface. In general the reason is that you need state. Even if you need implementations, I don't know if it would be justifiable, even more in Java 8 with the http://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html . Unless you need to implement "implementation details", that is, private methods.The way Funcionario is described to me seems to be declaring some characteristics that an element that is an employee of some kind should have. What is different from saying that Funcionario contains important definitions for who are employees. It's the famous difference being and have. Use classes when the derived classes will be that in this case, are employees. Or use interfaces when derived class only they have those characteristics, defined behaviors (but not implemented).By name it can be tempting to think Geek or Analista are employees and not only have characteristics of an employee. But the code shows something different. Therefore the correct specification is important to make the correct choice. Maybe you know something we don't know.About this can learn more about in https://pt.stackoverflow.com/q/53468/101 (in English, as always, is better) ( https://pt.stackoverflow.com/q/53468/101 ).Remember that in thesis it is easier to turn an interface into abstract class if one day this is necessary than the other. In fact, they're both going to work and bring risks.Really performance and other technical issues are little important near the engineering problem you will have. In general it is easier to add interfaces. You could have advantages in the abstract class if you want implement or modify existing implementations in it and this is automatically reflected in the descending classes. But this needs to be done so carefully that it is always necessary to question whether it is worth it.

With the help of @GuilhermeCostamilam I found the answer, nn gets so beautiful but the to use, so the code:Interface: import {Agenda} from "../model/agenda"; import {Observable} from "rxjs/index"; export interface AgendaCommandRepository { insert(agenda: Agenda): Observable<Agenda>; update(agenda: Agenda): Observable<Agenda>; deleteAgenda(id: number): Observable<number>; } Class that implements the interface:import { Injectable } from '@angular/core'; import { AgendaService } from '../service/agenda-command.service'; import { AgendaCommandValidator } from '../validator/agenda-command-validator'; import { Agenda } from '../../model/agenda'; import { Observable } from 'rxjs/index'; @Injectable({ providedIn: 'root' }) export class AgendaCommandRepositoryImpl implements AgendaCommandRepository { private service: AgendaService; private validator: AgendaCommandValidator; constructor(serviceImpl: AgendaServiceImpl, validatorImpl: AgendaCommandValidatorImpl) { this.service = serviceImpl; this.validator = validatorImpl; } insert(agenda: Agenda): Observable<Agenda> { if (this.validator.validaInsert(agenda)) { return this.service.insert(agenda); } return null; } update(agenda: Agenda): Observable<Agenda> { if (this.validator.validaUpdate(agenda)) { return this.service.update(agenda); } return null; } deleteAgenda(id: number): Observable<number> { if (this.validator.validaDelete(id)) { return this.service.deleteAgenda(id); } return null; } } Component:import {Component, Inject, OnInit} from '@angular/core'; import { AgendaCommandRepositoryImpl } from "../../repository/agenda-command-repository-impl"; import { Agenda } from "../../../model/agenda"; import { AgendaQueryRepository } from "../../../query/repository/agenda-query-repository"; import { ActivatedRoute } from '@angular/router'; import { AgendaCommandRepository } from "../../agenda-command-repository"; @Component({ selector: 'app-agenda', templateUrl: './agenda-command.component.html', styleUrls: ['./agenda-command.component.css'] }) export class AgendaCommandComponent implements OnInit { agenda: Agenda; id: number; titulo: string; // para teste private repository: AgendaCommandRepository; private queryRepository: AgendaQueryRepository; constructor(repositoryImpl: AgendaCommandRepositoryImpl, queryRepositoryImpl: AgendaQueryRepositoryImpl, private route: ActivatedRoute) { this.repository = repositoryImpl; this.queryRepository = queryRepositoryImpl; } ngOnInit() { this.id = +this.route.snapshot.paramMap.get('id'); if (this.id) { this.queryRepository.findById(this.id).subscribe(agenda =&gt; this.agenda = agenda); this.titulo = "Edição"; } else { this.agenda = new Agenda(); this.titulo = "Cadastro"; } } salvar() { if (this.id) { this.repository.update(this.agenda).subscribe(); } else { this.repository.insert(this.agenda).subscribe(); } } } As Angular 6 already makes the class injection for me I just needed to make Angular inject Impl(q is the code) and make the interface receive Impl, that's vlw flw!

You need declares two interfaces and use one inside the other: export interface Compra { event: string; timestamp: number; custom_data: CustomData[]; } export interface CustomData{ value: string; key: number; }

In PHP? It really doesn't have much advantage, but it's changing with language metamorphosis.If you are programming how PHP has been designed really doesn't make sense because interface is a contract mechanism where you say that methods a type of have and there you create types that conform to it, and in your code you can say that somewhere accepts an interface and there any object that implements the interface can be used there because it meets the requirement of it.It is a way for you to give a name for an operation that an object can do, and then it can say that it accepts objects that know how to do the operation. So it's a mechanism to ensure robustness, give type security.But PHP is a dynamic typing language, and it doesn't make sense to ask for type security in such a language. PHP is a language of script and should not have to deal with this kind of complexity.It is true that PHP has realized that this is not very good and is changing philosophy, but it can't arrange everything for compatibility issues, so it gets a hybrid thing and has the worst of both worlds (part of the best too, of course, but partial does not help so much).You want security guys? Great, use in a static typing language that forces this to occur in all cases. Do you like PHP? Use https://pt.stackoverflow.com/q/143708/101 . If you don't think about Java, C#, that stuff.You don't mind guys' safety? Okay, if really what you do is script it is not so necessary, but then it becomes strange to use interface.If you understand everything you're doing in the code you'll see that much of what you're preaching today in PHP doesn't make sense. People use without questioning. I'm glad you asked.See more at: https://pt.stackoverflow.com/q/136404/101 https://pt.stackoverflow.com/q/107524/101 https://pt.stackoverflow.com/q/35317/101 https://pt.stackoverflow.com/q/86484/101 https://pt.stackoverflow.com/q/166530/101 https://pt.stackoverflow.com/q/47925/101

Once MemberNames is a string[] and you want to recover the first value of the same you can explicitly use the index 0, provided that you check if in fact the array was booted. Another option is the method FirstOrDefault(), adding the reference of System.Linq.var _obj = ""; var memberNames = error.MemberNames; //Pelo índice _obj = (memberNames != null) ? memberNames[0] : ""; //Usando Linq _obj = memberNames?.FirstOrDefault() ?? ""; After you edit your question, with your code is the class that is validating, I edit the question with a more complete answer.

In PHP it is implemented in the same way as in Java. https://refactoring.guru/pt-br/design-patterns/strategy/php/example#example-0 provides a clear and didactic concept example as well as a practical example on how to use the pattern.And https://refactoring.guru/pt-br/design-patterns/strategy you will find more details.I hope I helped.

Yes, it would actually work analogously. Suppose the method List Selecionar(IEnumerable operadores), requested as an example:public override List<MeuObjeto> Selecionar(IEnumerable<Operadores.Operador> operadores) { using (SqlConnection con = new SqlConnection(ConnectionString)) { SqlCommand cmd = new SqlCommand("spMinhaSpDeSelecao", con); cmd.CommandType = System.Data.CommandType.StoredProcedure; foreach (var operador in operadores) { cmd.Parameters.AddWithValue("@" + operador.Nome, operador.Valor); } SqlParameter valorSaida = new SqlParameter(); valorSaida.ParameterName = "@ValorSaida"; valorSaida.SqlDbType = System.Data.SqlDbType.Int; valorSaida.Direction = System.Data.ParameterDirection.Output; cmd.Parameters.Add(valorSaida); con.Open(); var reader = cmd.ExecuteReader(); while (reader.Read()) { yield return new MeuObjeto { Campo1 = reader["Campo1"].ToString(), Campo2 = reader["Campo2"].ToString(), Campo3 = reader["Campo3"].ToString(), ... }; } reader.Close(); } }

I've been there too, very recently.Whenever I dragged a new component to the activity the android studio I stopped, I realized that this was happening because that element was not "off-line" and the android studio he immediately began to search for dependencies and add in the project, but stopped for lack of memory, processing or faith.To solve this, I:I closed everything that was open, left only the android studio.I closed my project and opened a new blank, with only one empty activity.I started dragging all the components into that empty activity, one to one, and every time I dragged I expected the IDE to finish process and download what needed the internet, even if it took a few minutes.After doing this with all the elements, and leaving all available offline, I deleted this test project and returned to mine, the problem stopped happening.Footnote: You should probably have an option to download all dependencies in some menu or option of gradle, but it must be very well hidden because I didn't find it in my IDE, so I made that gambiarra manually.

Creating for creating without a reason has no advantage. In everything you do, everything even, until you put a blank space in the code you need to find a motivation.That's why I always talk to people to give up this good practice thing. In practice they serve people followed cake recipes without thinking about what they are doing.Can you find a reason?I can say one: have an abstraction to be able to accept a generic type and the concrete is different in each situation. It's called https://pt.stackoverflow.com/q/86484/101 .Do you need to have that abstraction?If you don't have that generality, I don't see why.There is a case that people say to do even if their domain does not need, which is the one of the test. Without this it becomes a little more complicated to test other things without being able to exchange the implementation. It is questionable if it is worth complicating the design concrete only facilitate the test.Still, will you need to change the implementation so you can do a better test?I still don't think you need it.It's not what to do that matters, it's knowing why to do it.

Today, this is not possible in the language, however, in version 8 of C#, it will be possible to have the default implementation of methods in interfaces, anyway, one of the interfaces should be implemented explicitly.

An interface contains settings for a group of related features that a class or a struct can implement.And below in the link:The interface does not provide any functionality that a class or a struct can inherit in the way it can inherit the functionality of the base classObviously that definition will change. This is normal in revisions even of the language specification.Everything that was said about C# interfaces becomes obsolete in C# 8. As already occurred in Java. That's why I talk to people to take care of what they read. That may have been posted with the best of intentions, being correct when posted, being from someone who knows the subject, but time makes it even wrong, without her knowing (or remember).Not in general. But nothing prevents a language from determining it can. It would be weird, but you can. It would probably stop being exactly an interface, even if it kept the name.In fact the interface becomes a https://pt.stackoverflow.com/q/279252/101 or almost. It's just a matter of keeping the name so as not to introduce a new keyword. He was https://pt.stackoverflow.com/q/156913/101 .In object-oriented programming, the interface of an object consists of a set of methods that an object must support.Wikipedia in Portuguese is not very good and because it is a source that is expected canonical, it should be more careful. It's almost that, but not 100%. It has a lot of licking in several articles about OOP, even in English, but in Portuguese, it is terrible.Why not use an abstract class instead of a Default Method to implement code in methods?Only an abstract class can be inherited. Interfaces can many. This is the main reason to have a new mechanism.What scenario would be useful to implement in the interface and that cannot be done with an abstract class?This one I just quoted. It also helps to give a slightly better semantic of intention.What will open useful, and that the abstract class already allowed, but with the limitation of being only an inherited, is that it can add a new method in the contract and not break the application because now all types that implement that interface do not have implementation of that method. The new way to use interface allows you to provide the implementation and there all types of implementers of it already gain the "free" behavior, and can overlay it, of course. It will also facilitate some design patterns, such as Adapter, for example.

This apostille is shaky today https://pt.stackoverflow.com/q/90168/101 .Type inheritance is to take on the contracts a guy offers, i.e. to have guaranteed all https://pt.stackoverflow.com/q/39870/101 a guy in a new guy. The guy inherits what's already been declared in another guy.Implementing inheritance receives the algorithm, the code that runs in the methods, and can even receive implementation details like the type fields. https://pt.stackoverflow.com/q/279252/101 .The implementation inheritance has to do with object orientation. The type inheritance has to do with static typing, or at least safe typing. https://pt.stackoverflow.com/q/263289/101 .

Yes, you can. As it is a language that accesses the operating system natively can do everything and more.Note that it's not the language that provides this capability, it's the operating system and the language library provides easy access.But it is quite different than what is done for web. Even the UX should be different. You as designer from UX should know that everything needs to be adapted to the user who will effectively use that and specific activity. What is good for a media is not good for another, what serves for an activity is a complicator to another, which pleases a disgraced audience another. Do not try to play what you did on the web, look for the right path for desktop or mobile.UX has nothing to do with animations, most of the time, at least not directly, it has to do with the experience, as the name itself says. It is common animation to make something funny and worsen the experience, that is not doing UX and entertainment. Animation can be used to improve the experience, and this does not occur in any situation.Sincerely when I see this kind of question, I'm a little apprehensive because it's probably better for the person not to do this. When the work to be done is complex, it depends on deep technical knowledge and experience to perform it properly, such a basic question connects the alert signal. The least of your problems is knowing what was asked. You have a long journey ahead.For example, you will have to decide that framework you will. Unless they've already decided for you, then the question would lose its sense. Can use the most traditional style of desktop applications ( https://en.wikipedia.org/wiki/Visual_Component_Library ), or the way it is considered more modern, which allows more visual and action customization, and is programmed in a more web-like manner ( https://en.wikipedia.org/wiki/FireMonkey ), but that does not mean that it does not have its disadvantages.It should not be new to you, but https://pt.stackoverflow.com/q/182537/101 .