好的，所以我已经在主要类中设置了这些关键事件：https://prnt.sc/jhbxz9。
我试图在这里完成的是使用我的主类中设置的这些关键事件，这样我就可以在我的子类（播放器）中使用peformAction下的if / else语句编写一个方法，以便在按下某个键时让玩家移动释放时停止移动。目前所有我可以做到的是始终向一个方向移动，直到它离开屏幕而不需要按任何键，但我想要它，以便在按下VK_LEFT时它改变velX但我知道如何引用我的子类中的键事件没有代码中断。最后一件事是我注意到每个关键事件都有setKey，这让我觉得我需要使用setKeys，但仍然没有。
Usfull屏幕截图，如果你不能被要求阅读所有代码。 玩家类（子类）：http://prntscr.com/jhbx58 + http://prntscr.com/jhbxim
GameManager类（主类）：http://prntscr.com/jhbxz9
GameManager类：
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.JFrame;
public class GameManager extends JFrame implements KeyListener {
private int canvasWidth;
private int canvasHeight;
private int borderLeft;
private int borderTop;
private BufferedImage canvas;
private Stage stage;
private Enemy[] enemies;
private Player player;
private Goal goal;
private Graphics gameGraphics;
private Graphics canvasGraphics;
private int numEnemies;
private boolean continueGame;
public static void main(String[] args) {
// During development, you can adjust the values provided in the brackets below
// as needed. However, your code must work with different/valid combinations
// of values.
GameManager managerObj = new GameManager(1920, 1280, 30);
}
public GameManager(int preferredWidth, int preferredHeight, int maxEnemies) {
this.borderLeft = getInsets().left;
this.borderTop = getInsets().top;
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
if (screenSize.width < preferredWidth) {
this.canvasWidth = screenSize.width - getInsets().left - getInsets().right;
} else {
this.canvasWidth = preferredWidth - getInsets().left - getInsets().right;
}
if (screenSize.height < preferredHeight) {
this.canvasHeight = screenSize.height - getInsets().top - getInsets().bottom;
} else {
this.canvasHeight = preferredHeight - getInsets().top - getInsets().bottom;
}
setSize(this.canvasWidth, this.canvasHeight);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
addKeyListener(this);
Random rng = new Random(2);
this.canvas = new BufferedImage(this.canvasWidth, this.canvasHeight, BufferedImage.TYPE_INT_RGB);
// Create a Stage object to hold the background images
this.stage = new Stage();
// Create a Goal object with its initial x and y coordinates
this.goal = new Goal(this.canvasWidth / 2, Math.abs(rng.nextInt()) % this.canvasHeight);
// Create a Player object with its initial x and y coordinates
this.player = new Player(this.canvasWidth - (Math.abs(rng.nextInt()) % (this.canvasWidth / 2)),
(Math.abs(rng.nextInt()) % this.canvasHeight));
// Create the Enemy objects, each with a reference to this (GameManager) object
// and their initial x and y coordinates.
this.numEnemies = maxEnemies;
this.enemies = new Enemy[this.numEnemies];
for (int i = 0; i < this.numEnemies; i++) {
this.enemies[i] = new Enemy(this, Math.abs(rng.nextInt()) % (this.canvasWidth / 4),
Math.abs(rng.nextInt()) % this.canvasHeight);
}
this.gameGraphics = getGraphics();
this.canvasGraphics = this.canvas.getGraphics();
this.continueGame = true;
while (this.continueGame) {
updateCanvas();
}
this.stage.setGameOverBackground();
updateCanvas();
}
public void updateCanvas() {
long start = System.nanoTime();
// If the player is alive, this should move the player in the direction of the
// key that has been pressed
// Note: See keyPressed and keyReleased methods in the GameManager class.
this.player.performAction();
// If the enemy is alive, the enemy must move towards the goal. The goal object
// is obtained
// via the GameManager object that is given at the time of creating an Enemy
// object.
// Note: The amount that the enemy moves by must be much smaller than that of
// the player above
// or else the game becomes too hard to play.
for (int i = 0; i < this.numEnemies; i++) {
this.enemies[i].performAction();
}
if ((Math.abs(this.goal.getX() - this.player.getX()) < (this.goal.getCurrentImage().getWidth() / 2))
&& (Math.abs(this.goal.getY() - this.player.getY()) < (this.goal.getCurrentImage().getWidth()
/ 2))) {
for (int i = 0; i < this.numEnemies; i++) {
// Sets the image of the enemy to the "dead" image and sets its status to
// indicate dead
this.enemies[i].die();
}
// Sets the image of the enemy to the "dead" image and sets its status to
// indicate dead
this.goal.die();
// Sets the background of the stage to the finished game background.
this.stage.setGameOverBackground();
this.continueGame = false;
}
// If an enemy is close to the goal, the player and goal die
int j = 0;
while (j < this.numEnemies) {
if ((Math.abs(this.goal.getX() - this.enemies[j].getX()) < (this.goal.getCurrentImage().getWidth() / 2))
&& (Math.abs(this.goal.getY() - this.enemies[j].getY())
< (this.goal.getCurrentImage().getWidth() / 2))) {
this.player.die();
this.goal.die();
this.stage.setGameOverBackground();
j = this.numEnemies;
this.continueGame = false;
}
j++;
}
try {
// Draw stage
this.canvasGraphics.drawImage(stage.getCurrentImage(), 0, 0, null);
// Draw player
this.canvasGraphics.drawImage(player.getCurrentImage(),
this.player.getX() - (this.player.getCurrentImage().getWidth() / 2),
this.player.getY() - (this.player.getCurrentImage().getHeight() / 2), null);
// Draw enemies
for (int i = 0; i < this.numEnemies; i++) {
this.canvasGraphics.drawImage(this.enemies[i].getCurrentImage(),
this.enemies[i].getX() - (this.enemies[i].getCurrentImage().getWidth() / 2),
this.enemies[i].getY() - (this.enemies[i].getCurrentImage().getHeight()
/ 2), null);
}
// Draw goal
this.canvasGraphics.drawImage(this.goal.getCurrentImage(),
this.goal.getX() - (this.goal.getCurrentImage().getWidth() / 2),
this.goal.getY() - (this.goal.getCurrentImage().getHeight() / 2), null);
} catch (Exception e) {
System.err.println(e.getMessage());
}
// Draw everything.
this.gameGraphics.drawImage(this.canvas, this.borderLeft, this.borderTop, this);
long end = System.nanoTime();
this.gameGraphics.drawString("FPS: " + String.format("%2d", (int) (1000000000.0 / (end - start))),
this.borderLeft + 50, this.borderTop + 50);
}
public Goal getGoal() {
return this.goal;
}
public void keyPressed(KeyEvent ke) {
// Below, the setKey method is used to tell the Player object which key is
// currently pressed.
// The Player object must keep track of the pressed key and use it for
// determining the direction
// to move.
if (ke.getKeyCode() == KeyEvent.VK_LEFT) {
this.player.setKey('L', true);
}
if (ke.getKeyCode() == KeyEvent.VK_RIGHT) {
this.player.setKey('R', true);
}
if (ke.getKeyCode() == KeyEvent.VK_UP) {
this.player.setKey('U', true);
}
if (ke.getKeyCode() == KeyEvent.VK_DOWN) {
this.player.setKey('D', true);
}
if (ke.getKeyCode() == KeyEvent.VK_ESCAPE) {
this.continueGame = false;
}
}
@Override
public void keyReleased(KeyEvent ke) {
// Below, the setKey method is used to tell the Player object which key is
// currently released.
// The Player object must keep track of the pressed key and use it for
// determining the direction
// to move.
if (ke.getKeyCode() == KeyEvent.VK_LEFT) {
this.player.setKey('L', false);
}
if (ke.getKeyCode() == KeyEvent.VK_RIGHT) {
this.player.setKey('R', false);
}
if (ke.getKeyCode() == KeyEvent.VK_UP) {
this.player.setKey('U', false);
}
if (ke.getKeyCode() == KeyEvent.VK_DOWN) {
this.player.setKey('D', false);
}
}
@Override
public void keyTyped(KeyEvent ke) {
}
}
我的播放器类（子类）：
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class Player {
private BufferedImage imageRunning;
private BufferedImage imageOver;
private BufferedImage imageCurrent;
int valx = 500;
int valy = 100;
public Player(int valx, int valy) {
try {
this.imageRunning = ImageIO.read(new File("C:/Users/HUS/Desktop/Assigment222/images/player-alive.png"));
this.imageOver = ImageIO.read(new File("C:/Users/HUS/Desktop/Assigment222/images/player-dead.png"));
} catch (IOException e) {
e.printStackTrace();
}
this.imageCurrent = this.imageRunning;
}
public BufferedImage getCurrentImage() {
return this.imageCurrent;
}
public void setGameOverBackground() {
this.imageCurrent = this.imageOver;
}
public void performAction() {
if(Player.setKey('D', true) == true) {
this.valx += 2;
}
else if(Player.setKey('D', false) == false) {
this.valx = 0;
}
return;
}
public int getX() {
return valx;
}
public int getY() {
return valy;
}
public void die() {
return;
}
public static boolean setKey(char c, boolean b) {
return b;
}
}
答案 0 :(得分：1)
因此，当调用keyPressed或keyReleased时，他们会调用Player.setKey。当调用它时，您将存储状态。
例如......
public class Player {
//...
// I really, really, really don't static been used this way, it
// has a bad code smell about it...
public static Set<Character> inputState = new TreeSet<Character>();
//...
public static void setKey(char c, boolean b) {
if (b) {
inputState.add(c);
} else {
inputState.remove(c);
}
}
}
所以，所有这一切都是将char添加到Set或删除它。由于Set保证了唯一性，因此我们不需要关心密钥是否已被按下。
然后在调用performAction时，检查输入是否在Set中，并采取适当的措施......
public void performAction() {
if (inputState.contains('U')) {
// Going up
} else if (inputState.contains('D')) {
// Going down
}
//... other inputs
}