所以我正在创建一个弹球游戏。我希望背景图片出现在菜单系统后面。截至目前，我的菜单系统看起来像这样（没有任何背景图片）
及其代码：
public class Game extends Canvas implements Runnable {
JFrame frame;
public static final int WIDTH = 640, HEIGHT = WIDTH / 12 * 9;
private Thread thread;
private boolean running = false;
private Handler handler;
private Random r;
private HUD hud;
private Spawn spawner;
private Menu menu;
public enum STATE {
Menu,
Help,
Game
};
public STATE gameState = STATE.Menu;
public Game(){
//All game objects
handler = new Handler();
menu = new Menu(this, handler);
this.addKeyListener(new KeyInput(handler));
this.addMouseListener(menu);
AudioPlayer.load();
AudioPlayer.getMusic("music").loop();
new Window(WIDTH, HEIGHT, "Pinball", this);
hud = new HUD();
spawner = new Spawn(handler,hud);
r = new Random();
if(gameState == STATE.Game){
handler.addObject(new Player(WIDTH/2-32, HEIGHT/2-32, ID.Player, handler));
//for(int i = 0; i < 20; i++){
handler.addObject(new BasicEnemy(r.nextInt(WIDTH),r.nextInt(HEIGHT), ID.BasicEnemy,handler));
}
}
public synchronized void start(){
thread = new Thread(this); //"this" is where the thread is going to be ran
thread.start();
running = true;
}
//Killing of the thead
public synchronized void stop(){
try {
thread.join();
running = false;
}catch(Exception e){
e.printStackTrace();
}
}
public void run(){
//Setting up the game loop, every game needs a loop!
this.requestFocus(); //Don't need to click on window to activate key control
long lastTime = System.nanoTime();
double amountOfTicks = 60.0;
double ns = 1000000000 / amountOfTicks;
double delta = 0;
long timer = System.currentTimeMillis();
int frames = 0;
while(running){
long now = System.nanoTime();
delta += (now - lastTime) / ns;
lastTime = now;
while(delta >= 1){
tick();
delta--;
}
if(running)
try {
render();
} catch (IOException ex) {
Logger.getLogger(Game.class.getName()).log(Level.SEVERE, null, ex);
}
frames++;
if(System.currentTimeMillis() - timer > 1000){
timer += 1000;
//System.out.println("FPS: " + frames);
frames = 0;
}
}
stop();
}
private void tick(){
handler.tick();
if(gameState == STATE.Game){
hud.tick();
spawner.tick();
}else if(gameState == STATE.Menu){
menu.tick();
}
}
private void render() throws IOException{
BufferStrategy bs = this.getBufferStrategy();
if(bs == null){
this.createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
//-------------------------------------
//Background color
g.setColor(Color.black);
g.fillRect(0,0, WIDTH, HEIGHT);
//-------------------------------------
handler.render(g);
if(gameState == STATE.Game){
hud.render(g);
}else if(gameState == STATE.Menu){
menu.render(g);
}else if(gameState == STATE.Menu.Help || gameState == STATE.Help){
menu.render(g);
}
g.dispose();
bs.show();
}
public static int clamp(int var, int min, int max){
if(var >= max)
return var = max;
else if (var <= min)
return var = min;
else
return var;
}
public static void main(String[] args) {
new Game();
}
}
我还有另一个叫做Window.java的类
public class Window extends Canvas {
public Window(int width, int height, String title, Game game){
JFrame frame = new JFrame(title);
frame.setPreferredSize(new Dimension(width, height));
frame.setMaximumSize (new Dimension(width, height));
frame.setMinimumSize (new Dimension(width, height));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
//Adding game class into the frame
frame.add(game);
game.start();
}
}
因此，如果我尝试在Window类中放入显示背景图片的代码，则背景图片将出现在整个菜单系统的前面。
Window类中的“背景图片”代码如下：
public class Window extends Canvas {
public Window(int width, int height, String title, Game game){
JFrame frame = new JFrame(title);
try {
frame.setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("C:/res/pinball.png")))));
} catch (IOException e) {
e.printStackTrace();
}
frame.setPreferredSize(new Dimension(width, height));
frame.setMaximumSize (new Dimension(width, height));
frame.setMinimumSize (new Dimension(width, height));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
//Adding game class into the frame
frame.add(game);
game.start();
}
}
结果是这样的：
Background picture in the frame
如何使图片显示在实际菜单系统后面？
我的Menu（系统）类代码如下：
public class Menu extends MouseAdapter {
//JFrame frame;
private Game game;
private Handler handler;
private Random r = new Random();
public static final int WIDTH = 640, HEIGHT = WIDTH / 12 * 9;
public Menu(Game game, Handler handler){
this.game = game;
this.handler = handler;
}
//When you click play it takes you over to the game
public void mousePressed(MouseEvent e){
int mx = e.getX();
int my = e.getY();
if(game.gameState == STATE.Menu){
//Play button
if(mouseOver(mx, my, 210, 150, 200, 64)){
game.gameState = STATE.Game;
handler.addObject(new Player(Game.WIDTH/2-32, Game.HEIGHT/2-32, ID.Player, handler));
handler.addObject(new BasicEnemy(r.nextInt(WIDTH),r.nextInt(HEIGHT), ID.BasicEnemy,handler));
}
//Help button
if(mouseOver(mx, my, 210, 250,200,64)){
game.gameState = STATE.Help;
}
//Quit button
if(mouseOver(mx, my, 210, 350, 200, 63)){
System.exit(1);
}
}
//Back button for help
if(game.gameState == STATE.Help){
if(mouseOver(mx, my, 210, 350, 200, 64)){
game.gameState = STATE.Menu;
}
}
}
public void mouseReleased(MouseEvent e){
}
//Method for checking if mouse is over a button in the menu
private boolean mouseOver(int mx, int my, int x, int y, int width, int height){
if(mx > x && mx < x + width){
if(my > y && my < y + height){
return true;
}else return false;
}else return false;
public void tick() {
}
public void render(Graphics g){
if(game.gameState == STATE.Menu){
Font fnt = new Font("Arial", 1, 50);
Font fnt2 = new Font("Arial", 1, 30);
g.setFont(fnt);
g.setColor(Color.green);
g.drawString("Menu", 240, 70);
g.setFont(fnt);
g.setColor(Color.green);
g.drawRect(210,150, 200, 64);
g.drawString("Play", 265, 200);
g.setColor(Color.green);
g.drawRect(210,250, 200, 64);
g.drawString("Help", 265, 300);
g.setColor(Color.green);
g.drawRect(210,350, 200, 64);
g.drawString("Quit", 265, 400);
}else if(game.gameState == STATE.Help) {
Font fnt = new Font("Arial", 1, 50);
Font fnt2 = new Font("Arial", 1, 30);
Font fnt3 = new Font("Arial", 1, 20);
g.setFont(fnt);
g.setColor(Color.green);
g.drawString("Help", 240, 70);
g.setFont(fnt3);
g.drawString("Use WASD keys to move player and dodge enemies", 60,200);
g.drawRect(210,350, 200, 64);
g.drawString("Back", 265, 400);
}