JPanel和彈出窗口的，在哪裏插入彈出的實例

Question

我正在做一個遊戲，我想有一個彈出窗口的選項，一旦採取了某些行動。我不知道在哪裏把彈出式jpanel的實例放在我的代碼中。我不希望它在主遊戲板的主JPanel的構造函數中，我試圖在主方法中添加它，但似乎沒有工作。建議嗎？

public class GameBoard extends JPanel { 

    public final int EARTH_ORBIT_RADIUS = 200; 
    public final int BOARD_WIDTH = 800; 
    public final int BOARD_HEIGHT = 600; 
    public final int INITIAL_EARTH_X = 700; 
    public final int INITIAL_EARTH_Y = 300; 
    public final int INITIAL_DELAY = 100; 
    public final int PERIOD_DELAY = 30; 
    public final static int SUN_COORDINATE_X = 500; 
    public final static int SUN_COORDINATE_Y = 300; 
    public final int INITIAL_ASTEROID_X = 500; 
    public final int INITIAL_ASTEROID_Y = 100; 
    public final int INITIAL_SHIP_X = 500; 
    public final int INITIAL_SHIP_Y = 500; 

    public static int earth_x, earth_y; 
    public static int asteroid_x, asteroid_y; 
    public static int ship_x, ship_y; 
    public int t = 0; 
    public int ship_t = 0; 
    public int keyheard = 0; 
    public int[] earthcoordinates; 
    public int[] asteroidcoordinates; 
    public int[] shipcoordinates; 

    public static boolean isCollision = false; 

    Image earth; 
    Image sun; 
    Image asteroid; 
    Image background; 
    Image ship, shipL, shipR, shipU, shipD; 

    Timer timer; 

    GameBoard() { 

     initGameBoard(); 

     loadImage(); 

     earth_x = INITIAL_EARTH_X; 
     earth_y = INITIAL_EARTH_Y; 

     asteroid_x = INITIAL_ASTEROID_X; 
     asteroid_y = INITIAL_ASTEROID_Y; 

     ship_x = INITIAL_SHIP_X; 
     ship_y = INITIAL_SHIP_Y; 

     timer = new Timer(); 
     timer.scheduleAtFixedRate(new ScheduledTask(), INITIAL_DELAY, 
       PERIOD_DELAY); 
    } 

    void initGameBoard(){ 

     setBackground(Color.BLACK); 
     setPreferredSize(new Dimension(BOARD_WIDTH, BOARD_HEIGHT)); 
     setDoubleBuffered(true); 
     addKeyListener(new KeyListen()); 
     setFocusable(true); 

    } 

    void loadImage() { 
     ImageIcon earth_image_icon = new ImageIcon("earth2.png"); 
     earth = earth_image_icon.getImage(); 

     ImageIcon sun_image_icon = new ImageIcon("sun.png"); 
     sun = sun_image_icon.getImage(); 

     ImageIcon asteroid_image_icon = new ImageIcon("asteroid.png"); 
     asteroid = asteroid_image_icon.getImage(); 

     ImageIcon bg_image_icon = new ImageIcon("bg_pr.png"); 
     background = bg_image_icon.getImage(); 

     ImageIcon ship_image_icon = new ImageIcon("ship.png"); 
     ship = ship_image_icon.getImage(); 

     ImageIcon shipL_image_icon = new ImageIcon("shipL.png"); 
     shipL = shipL_image_icon.getImage(); 

     ImageIcon shipR_image_icon = new ImageIcon("shipR.png"); 
     shipR = shipR_image_icon.getImage(); 

     ImageIcon shipU_image_icon = new ImageIcon("shipU.png"); 
     shipU = shipU_image_icon.getImage(); 

     ImageIcon shipD_image_icon = new ImageIcon("shipD.png"); 
     shipD = shipD_image_icon.getImage(); 


    } 

    public void paintComponent(Graphics g) { 
     super.paintComponent(g); 

     drawBackground(g); 
     drawEarth(g); 
     drawSun(g); 
     drawAsteroid(g); 
     drawShip(g); 

    } 

    void drawEarth(Graphics g) { 

     g.drawImage(earth, earth_x, earth_y, this); 
     Toolkit.getDefaultToolkit().sync(); 
    } 

    void drawSun(Graphics g) { 
     g.drawImage(sun, SUN_COORDINATE_X, SUN_COORDINATE_Y, this); 
     Toolkit.getDefaultToolkit().sync(); 
    } 

    void drawAsteroid(Graphics g) { 
     g.drawImage(asteroid, asteroid_x, asteroid_y, this); 
     Toolkit.getDefaultToolkit().sync(); 
    } 

    void drawBackground(Graphics g) { 
     g.drawImage(background, 0, 0, null); 
    } 

    void drawShip(Graphics g){ 
     if(keyheard == 0 || isCollision == true){g.drawImage(ship,ship_x, ship_y, this);} 
     else if(keyheard == 1){g.drawImage(shipL,ship_x, ship_y, this);} 
     else if(keyheard == 2){g.drawImage(shipR,ship_x, ship_y, this);} 
     else if(keyheard == 3){g.drawImage(shipU,ship_x, ship_y, this);} 
     else if(keyheard == 4){g.drawImage(shipD,ship_x, ship_y, this);} 

    } 
    public class ScheduledTask extends TimerTask { 

     @Override 
     public void run() { 

      OrbitCalculation oe = new OrbitCalculation(); 
      earthcoordinates = oe.earthOrbitCalculation(t); 
      earth_x = earthcoordinates[0]; 
      earth_y = earthcoordinates[1]; 

      OrbitCalculation oa = new OrbitCalculation(); 
      asteroidcoordinates = oa.asteroidOrbitCalculation(t); 
      asteroid_x = asteroidcoordinates[0]; 
      asteroid_y = asteroidcoordinates[1]; 

      OrbitCalculation os = new OrbitCalculation(); 
      shipcoordinates = os.shipOrbitCalculation(ship_t,keyheard, ship_x, ship_y); 
      ship_x = shipcoordinates[0]; 
      ship_y = shipcoordinates[1]; 

      CollisionDetector c = new CollisionDetector(); 

      if(c.whoCollision() == "asteroid"){ 
       ship_x = asteroid_x; 
       ship_y = asteroid_y; 

       isCollision = true; 


      } 
      else if(c.whoCollision() == "earth"){ 
       ship_x = earth_x; 
       ship_y = earth_y; 

       isCollision = true; 
      } 
      else{ isCollision = false;} 

      //if(GameBo 

      t = t + 1; 
      ship_t = ship_t + 1; 


      repaint(); 
     } 
    } 

    public class KeyListen extends KeyAdapter { 

     @Override 
     public void keyPressed(KeyEvent e){ 
      int key = e.getKeyCode(); 

      if(key == KeyEvent.VK_LEFT){ 
       keyheard = 1; 
      } 

      if(key == KeyEvent.VK_RIGHT){ 
       keyheard = 2; 
      } 
      if(key == KeyEvent.VK_UP){ 
       keyheard = 3; 
      } 
      if(key == KeyEvent.VK_DOWN){ 
       keyheard = 4; 
      } 
     } 
     /**public int[] lastTwoKeys(KeyEvent e){ 
      last_two_keys[1] = last_two_keys[0]; 
      last_two_keys[0] = keyheard; 

      return last_two_keys; 

     }*/ 

    } 
} 

Answer 1

您可以使用JOptionPane創建彈出窗口。請參閱：http://docs.oracle.com/javase/7/docs/api/javax/swing/JOptionPane.html
無需在構造函數中聲明此組件。