implements

问题 In java when an interface extends another interface: Why does it implement its methods? How can it implement its methods when an interface can't contain a method body How can it implement the methods when it extends the other interface and not implement it? What is the purpose of an interface implementing another interface? This has major concepts in Java! EDIT: public interface FiresDragEvents { void addDragHandler(DragHandler handler); void removeDragHandler(DragHandler handler); } public

问题 I'm trying to add dependency injection to a plain Typescript project, found an npm package called inversify. So looking at the examples I came across this code: import { Container, injectable, inject } from "inversify"; @injectable() class Katana { public hit() { return "cut!"; } } @injectable() class Shuriken { public throw() { return "hit!"; } } @injectable() class Ninja implements Ninja { private _katana: Katana; private _shuriken: Shuriken; public constructor(katana: Katana, shuriken:

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 4 years ago . I would like to create a programme based on a robot scenario, that includes abstract classes, interface types and array lists. Can anyone give me some advice on how to create this scenario (via a UML diagram to show how everything links). This scenario needs to include some complex methods, but I

问题 In my program, I write my own LinkedList class. And an instance, llist. To use it in foreach loop as following, LinkedList needs to implement Iterable? for(Node node : llist) { System.out.print(node.getData() + " "); } Here following is my LinkedList class. Please let me know how can I make it Iterable? public class LinkedList implements Iterable { private Node head = null; private int length = 0; public LinkedList() { this.head = null; this.length = 0; } LinkedList (Node head) { this.head =

问题 I have public class MainFrame extends JFrame implements ActionListener { and then later on: public void keyPressed(KeyEvent e) { if (e.getKeyCode() == e.VK_LEFT) { int x = ball.getX() + 1; ball.setX(x); } } however it does not seem to respond when I believe it should. If I add keylistener instead of actionlister I cannot compile which I can't understand. I'm new to java however i'm used to C# 回答1: You need to implement java.awt.event.KeyListener not a ActionListener to listen for key events.

问题 Here is the code I'm having problems with: The interface: public interface anInterface { void printSomething(); } Class that implements the interface: public class aClass implements anInterface { public aClass() { } public void printSomethingElse() { System.out.println("Something else"); } @Override public void printSomething() { System.out.println("Something"); } } And the main function: public static void main(String[] args) { anInterface object = new aClass(); object.printSomething(); //

问题 I am using Xamarin and I am wanting to create a CustomWindowAdapter that implements a GoogleMap.InfoWindowAdapter interface. I have tried this so far: public class CustomWindowAdapter : InfoWindowAdapter { } I am getting this error: Error CS0246: The type or namespace name 'InfoWindowAdapter' could not be found (are you missing a using directive or an assembly reference?) Here is the documentation for the interface: https://developers.google.com/maps/documentation/android/reference/com/google

问题 import javax.swing.*; import java.awt.*; import java.awt.event.ActionListener; import java.awt.event.*; import java.io.*; import java.util.*; public class WetBulbByLocationFrame2 extends JFrame { public JLabel countryLabel = new JLabel("Country"); public JPanel countryPanel = new JPanel(); public JComboBox countryBox; public String [] northAmericanCountries = {"Antigua", "Aruba", "Bahamas", "Barbados", "Bermuda", "Canada", "Costa Rica", "Cuba", "Dominican Republic", "Grenada", "Guadalupe",

问题 I need to have a variable in a class which is an instance of class "ClassA" but which also implements interface "InterfaceI". Obviously this can be done for one or the other easily: private ClassA mVariable; private InterfaceI mVaraible; but how can I enforce the object both extends ClassA and implements InterfaceB? Something like: private <? extends ClassA & InterfaceI> mVaraible; is what I need but I have no idea of the syntax or if it is even possible. I will also need a get and set method

问题 I got a simple question: Why does Eclipse scream about implementing these two interfaces? public abstract class Gateway implements IPlayerity, IItemity { public interface IPlayerity { ... } public interface IItemity { ... } // I...ity } I get this error message: IPlayerity cannot be resolved to a type 回答1: You have a cyclic dependency that can't be resolved given the way the JLS works (although I'm not sure where in the JLS this is documented). The interfaces IPlayerity and IItemity are not