創建額外的菜單選項去其他選項

Question

所以，我有一個命令的菜單：「按Enter鍵」將玩遊戲。我希望有一些額外的選項來調整我的菜單屏幕。換句話說，我希望有一個按鍵可以進入指令「頁面」，它將指導如何玩遊戲。 我當前的菜單代碼：

package menupackagev1; 

import java.awt.Canvas; 
import java.awt.Color; 
import java.awt.Font; 
import java.awt.Graphics2D; 
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener; 

import displaypackagev1.Sea_InvadersDisplay; 
import statepackagev1.Sea_InvadersStateMachine; 
import statepackagev1.StateMachineInterface; 

public class MenuScreen extends StateMachineInterface implements KeyListener { 

private Font titleFont = new Font("Arial", Font.PLAIN, 64); 
private Font startFont = new Font("Arial", Font.PLAIN, 32); 
private String title = "Space Invaders"; 
private String start = "Press Enter"; 
private String instruct = " Press H for Instructions"; 

public MenuScreen(Sea_InvadersStateMachine stateMachine) { 
    super(stateMachine); 
} 

@Override 
public void update(double delta) { 

} 

@Override 
public void draw(Graphics2D g) { 
    g.setFont(titleFont); 
    int tittleWidth = g.getFontMetrics().stringWidth(title); 
    g.setColor(Color.yellow); 
    g.drawString(title, ((Sea_InvadersDisplay.WIDTH/2)-(tittleWidth/2))-2, (Sea_InvadersDisplay.HEIGHT/2)-123); 
    g.setColor(Color.green); 
    g.drawString(title, (Sea_InvadersDisplay.WIDTH/2)-(tittleWidth/2), (Sea_InvadersDisplay.HEIGHT/2)-125); 

    g.setFont(startFont); 
    g.setColor(Color.white); 
    int startWidth = g.getFontMetrics().stringWidth(start); 
    g.drawString(start, (Sea_InvadersDisplay.WIDTH/2)-(startWidth/2), (Sea_InvadersDisplay.HEIGHT/2)+75); 
} 

@Override 
public void init(Canvas canvas) { 
    canvas.addKeyListener(this); 
} 

@Override 
public void keyPressed(KeyEvent e) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void keyReleased(KeyEvent e) { 
    if (e.getKeyCode() == KeyEvent.VK_ENTER) { 
     getStateMachine().setState((byte) 1); 
    } 
} 

@Override 
public void keyTyped(KeyEvent e) { 
    // TODO Auto-generated method stub 

    } 

} 

顯示：

package displaypackagev1; 

import java.awt.Canvas; 
import java.awt.Color; 
import java.awt.Graphics2D; 
import java.awt.image.BufferStrategy; 

import javax.swing.JFrame; 

import statepackagev1.Sea_InvadersStateMachine; 

public class Sea_InvadersDisplay extends Canvas implements Runnable { 

private static final long serialVersionUID = 1L; 

public static void main(String[] args) { 
    Sea_InvadersDisplay display = new Sea_InvadersDisplay(); 
    JFrame frame = new JFrame(); 
    frame.add(display); 
    frame.pack(); 
    frame.setTitle("Space Invaders"); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    frame.setResizable(false); 
    frame.setVisible(true); 
    display.start(); 
} 

private boolean running = false; 
private Thread thread; 

public synchronized void start() { 
    if (running) 
     return; 

    running = true; 

    thread = new Thread(this); 
    thread.start(); 
} 

public synchronized void stop() { 
    if (!running) 
     return; 

    running = false; 

    try { 
     thread.join(); 
    } catch (InterruptedException e) { 
     e.printStackTrace(); 
    } 
} 

public static int WIDTH = 800, HEIGHT = 600; 
public int FPS; 

public static Sea_InvadersStateMachine state; 

public Sea_InvadersDisplay() { 
    this.setSize(WIDTH, HEIGHT); 
    this.setFocusable(true); 

    state = new Sea_InvadersStateMachine(this); 
    state.setState((byte) 0); 
} 

@Override 
public void run() { 
    long timer = System.currentTimeMillis(); 
    long lastLoopTime = System.nanoTime(); 
    final int TARGET_FPS = 60; 
    final long OPTIMAL_TIME = 1000000000/TARGET_FPS; 
    int frames = 0; 

    this.createBufferStrategy(3); 
    BufferStrategy bs = this.getBufferStrategy(); 
    while (running) { 
     long now = System.nanoTime(); 
     long updateLength = now - lastLoopTime; 
     lastLoopTime = now; 
     double delta = updateLength/((double) OPTIMAL_TIME); 

     frames++; 

     if (System.currentTimeMillis() - timer > 1000) { 
      timer += 1000; 
      FPS = frames; 
      frames = 0; 
      System.out.println(FPS); 
     } 

     draw(bs); 
     update(delta); 

     try { 
      Thread.sleep(((lastLoopTime - System.nanoTime()) + OPTIMAL_TIME)/1000000); 
     } catch (Exception e) { 
     } 
     ; 
    } 
} 

public void draw(BufferStrategy bs) { 
    do { 
     do { 
      Graphics2D g = (Graphics2D) bs.getDrawGraphics(); 
      g.setColor(Color.BLUE); 
      g.fillRect(0, 0, WIDTH + 50, HEIGHT + 50); 

      state.draw(g); 

      g.dispose(); 
     } while (bs.contentsRestored()); 
     bs.show(); 
    } while (bs.contentsLost()); 
} 

public void update(double delta) { 
    state.update(delta); 
    } 

} 

狀態機：

package statepackagev1; 

import java.awt.Canvas; 
import java.awt.Graphics2D; 
import java.util.ArrayList; 

import menupackagev1.MenuScreen; 
import gamescreenpackagev1.GameScreen; 

public class Sea_InvadersStateMachine { 
private ArrayList<StateMachineInterface> states = new ArrayList<StateMachineInterface>(); 
private Canvas canvas; 
private byte selectState = 0; 

public Sea_InvadersStateMachine(Canvas canvas){ 
    StateMachineInterface game = new GameScreen(this); 
    StateMachineInterface menu = new MenuScreen(this); 
    states.add(menu); 
    states.add(game); 

    this.canvas = canvas; 
} 

public void draw(Graphics2D g){ 
    states.get(selectState).draw(g); //Depending on which State is selected, that state that has been selected will be drawn. 
} 

public void update(double delta){ 
    states.get(selectState).update(delta); 
} 

public void setState(byte i){ 
    for(int r =0; r < canvas.getKeyListeners().length; r++) 
     canvas.removeKeyListener(canvas.getKeyListeners()[r]); 
    selectState = i; 
    states.get(selectState).init(canvas); 
} 

public byte getStates() { 
    return selectState; 
    } 
} 

SM接口：

package statepackagev1; 

import java.awt.Canvas; 
import java.awt.Graphics2D; 

public abstract class StateMachineInterface { 

private Sea_InvadersStateMachine stateMachine; 

public StateMachineInterface(Sea_InvadersStateMachine stateMachine) { 
    this.stateMachine = stateMachine; 
} 

public abstract void update(double delta); 
public abstract void draw(Graphics2D g); 
public abstract void init(Canvas canvas); 

public Sea_InvadersStateMachine getStateMachine() { 
    return stateMachine; 
    } 
} 

Answer 1

在你MenuScreen類：

@Override 
public void keyReleased(KeyEvent e) { 
    if (e.getKeyCode() == KeyEvent.VK_ENTER) { 
     getStateMachine().setState((byte) 1); 
    } else if (e.getKeyCode() == KeyEvent.SOME_OTHER_KEY) { 
     // Do some other stuff here... 
    } 
}