我有这3个课程，它们可以共同创造一个游戏。但我在其中一个地方遇到错误，它要我添加未实现的方法。创建错误的类称为Game，看起来像这样。
package org.game.main;
import java.awt.Graphics2D;
public class Game extends Window {
public static void main(String[] args) {
Window window = new Game();
window.run(1.0 / 60.0);
System.exit(0);
}
public Game() {
// call game constructor
super("Test Game", 640, 480);
}
public void gameStartup() {
}
public void gameUpdate(double delta) {
}
public void gameDraw(Graphics2D g) {
}
public void gameShutdown() {
}
}
它希望我从Update()类实现名为Window的方法。 Window类看起来像这样。
package org.game.main;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics2D;
import java.awt.image.BufferStrategy;
import org.game.input.*;
/**
* Game that creates a window and handles input.
* @author Eric
*/
public abstract class Window extends GameLoop {
private Frame frame;
private Canvas canvas;
private BufferStrategy buffer;
private Keyboard keyboard;
private Mouse mouse;
private MouseWheel mouseWheel;
/**
* Creates a new game window.
*
* @param title title of the window.
* @param width width of the window.
* @param height height of the window.
*/
public Window(String title, int width, int height) {
/*Log.debug("Game", "Creating game " +
title + " (" + width + ", " + height + ")");*/
// create frame and canvas
frame = new Frame(title);
frame.setResizable(false);
canvas = new Canvas();
canvas.setIgnoreRepaint(true);
frame.add(canvas);
// resize canvas and make the window visible
canvas.setSize(width, height);
frame.pack();
frame.setVisible(true);
// create buffer strategy
canvas.createBufferStrategy(2);
buffer = canvas.getBufferStrategy();
// create our input classess and add them to the canvas
keyboard = new Keyboard();
mouse = new Mouse();
mouseWheel = new MouseWheel();
canvas.addKeyListener(keyboard);
canvas.addMouseListener(mouse);
canvas.addMouseMotionListener(mouse);
canvas.addMouseWheelListener(mouseWheel);
canvas.requestFocus();
}
/**
* Get the width of the window.
*
* @return the width of the window.
*/
public int getWidth()
{
return canvas.getWidth();
}
/**
* Get the height of the window.
*
* @return the height of the window.
*/
public int getHeight()
{
return canvas.getHeight();
}
/**
* Returns the title of the window.
*
* @return the title of the window.
*/
public String getTitle()
{
return frame.getTitle();
}
/**
* Returns the keyboard input manager.
* @return the keyboard.
*/
public Keyboard getKeyboard()
{
return keyboard;
}
/**
* Returns the mouse input manager.
* @return the mouse.
*/
public Mouse getMouse()
{
return mouse;
}
/**
* Returns the mouse wheel input manager.
* @return the mouse wheel.
*/
public MouseWheel getMouseWheel() {
return mouseWheel;
}
/**
* Calls gameStartup()
*/
public void startup() {
gameStartup();
}
/**
* Updates the input classes then calls gameUpdate(double).
* @param delta time difference between the last two updates.
*/
public void update(double delta) {
// call the input updates first
keyboard.update();
mouse.update();
mouseWheel.update();
// call the abstract update
gameUpdate(delta);
}
/**
* Calls gameDraw(Graphics2D) using the current Graphics2D.
*/
public void draw() {
// get the current graphics object
Graphics2D g = (Graphics2D)buffer.getDrawGraphics();
// clear the window
g.setColor(Color.BLACK);
g.fillRect(0, 0, canvas.getWidth(), canvas.getHeight());
// send the graphics object to gameDraw() for our main drawing
gameDraw(g);
// show our changes on the canvas
buffer.show();
// release the graphics resources
g.dispose();
}
/**
* Calls gameShutdown()
*/
public void shutdown() {
gameShutdown();
}
public abstract void gameStartup();
public abstract void gameUpdate(double delta);
public abstract void gameDraw(Graphics2D g);
public abstract void gameShutdown();
}
最后一个类名为Gameloop，看起来像这样。
package org.game.main;
public abstract class GameLoop {
private boolean runFlag = false;
/**
* Begin the game loop
* @param delta time between logic updates (in seconds)
*/
public void run (double delta) {
runFlag = true;
startup();
// convert the time to seconds
double nextTime = (double) System.nanoTime() / 1000000000.0;
double maxTimeDiff = 0.5;
int skippedFrames = 1;
int maxSkippedFrames = 5;
while (runFlag) {
// convert the time to seconds
double currTime = (double) System.nanoTime() / 1000000000.0;
if ((currTime - nextTime) > maxTimeDiff) nextTime = currTime;
if (currTime >= nextTime) {
// assign the time for the next update
nextTime += delta;
update();
if ((currTime < nextTime) || (skippedFrames > maxSkippedFrames)) {
draw();
skippedFrames = 1;
}
else {
skippedFrames++;
}
} else {
// calculate the time to sleep
int sleepTime = (int)(1000.0 * (nextTime - currTime));
// sanity check
if (sleepTime > 0) {
// sleep until the next update
try {
Thread.sleep(sleepTime);
}
catch(InterruptedException e) {
// do nothing
}
}
}
}
shutdown();
}
public void stop() {
runFlag = false;
}
public abstract void startup();
public abstract void shutdown();
public abstract void update();
public abstract void draw();
}
运行主类时我在控制台中遇到的错误就像这样。
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The type Game must implement the inherited abstract method GameLoop.update()
at org.game.main.Game.update(Game.java:5)
at org.game.main.GameLoop.run(GameLoop.java:26)
at org.game.main.Game.main(Game.java:8)
我希望你能帮助我。我对java很新。
答案 0 :(得分：2)
如果符合您的意图，更新方法的签名不会覆盖界面。
public void update(double delta)
您需要它来匹配界面
public abstract void update();
所以听起来这个简单的改变应该会有所帮助：
public abstract void update(double delta);
答案 1 :(得分：0)
在GameLoop已定义
public abstract void update();
此方法必须在其中一个子类Window或Game中使用相同的签名实现。
答案 2 :(得分：0)
您已经实现了Game Window和GameLoop类的未实现方法
实施抽象方法。 Window类的抽象方法如下：
public abstract void gameStartup();
public abstract void gameUpdate(double delta);
public abstract void gameDraw(Graphics2D g);
public abstract void gameShutdown();
同时实现GameLoop类的以下方法
public abstract void startup();
public abstract void shutdown();
public abstract void update();
public abstract void draw();
答案 3 :(得分：0)
好的，我发现了你提出的一些帮助。这是因为我没有在GameLoop中将Update（）定义为。
public abstract void update(double delta);
Insted of
public abstract void update();
因此该方法未在Window中调用。所以它必须在游戏中调用。感谢您的帮助，现在一切正常。