java - AWT fillOvalは新しいオブジェクトを描画しません

Question

私はウェブサイトから古いping-pong gameのサンプルコードを修正するために、2番目のボールを練習としてパネルに追加します。これまでのところ、私は最初のボールを生成する手順を複製しています。しかし、どういうわけか私は失敗しました。プログラムは実行可能ですが、追加した2番目のボールは表示されませんでした。私はどこに問題があるのか​​分からない。ボールメソッドはPanelPelotaクラスの下にあります。これまでは変数といくつかの関数を単純に複製しています。それならば、私はEclipse IDEを使用しています（私が作成したもの）

メインクラス

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 

public class Main extends JFrame { 

private static final long serialVersionUID = 1L; // Eclipse added this automatically 

private JPanel jContentPane = null; 

private PanelPelota panel = null; // This is the panel of the game class 

private PanelPelota getPanel() { 
    if (panel == null) { 
     panel = new PanelPelota(); // The panel is created 
    } 
    return panel; 
} 

/** 
* This is the default constructor 
*/ 
public Main() { 
    super(); 
    initialize(); 
    // Listeners for the keyboard 
    this.addKeyListener(new KeyAdapter() { 
     // Method for the key pressed 
     public void keyPressed(KeyEvent evt) { 
      formKeyPressed(evt); 
     } 

     // Method for the key released 
     public void keyReleased(KeyEvent evt) { 
      formKeyReleased(evt); 
     } 
    }); 

} 

// Here i'm stating the method that will send the key pressed to the game class 
private void formKeyPressed(KeyEvent evt) { 
    panel.keyPressed(evt); 
} 

// Here i'm stating the method that will send the key released to the game class 
private void formKeyReleased(KeyEvent evt) { 
    panel.keyReleased(evt); 
} 

/** 
* This method initializes this 
* 
* @return void 
*/ 
private void initialize() { 
    this.setResizable(false); 
    this.setBounds(new Rectangle(312, 184, 250, 250)); // Position on the desktop 
    this.setMinimumSize(new Dimension(250, 250)); 
    this.setMaximumSize(new Dimension(250, 250)); 
    this.setContentPane(getJContentPane()); 
    this.setTitle("Pong"); 
} 

/** 
* This method initializes jContentPane 
* 
* @return javax.swing.JPanel 
*/ 
private JPanel getJContentPane() { 
    if (jContentPane == null) { 
     jContentPane = new JPanel(); 
     jContentPane.setLayout(new BorderLayout()); 
     jContentPane.add(getPanel(), BorderLayout.CENTER); 
    } 
    return jContentPane; 
} 

public static void main(String[] args) { 
    // TODO Auto-generated method stub 
    SwingUtilities.invokeLater(new Runnable() { 
     public void run() { 
      Main thisClass = new Main(); 
      thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
      thisClass.setVisible(true); 
     } 
    }); 
} 
} 

PanelPelotaクラス

import java.awt.*; 
import java.awt.event.KeyEvent; 
import javax.swing.*; 

public class PanelPelota extends JPanel implements Runnable { 

private static final long serialVersionUID = 1L; 
// Positions on X and Y for the ball, player 1 and player 2 
private int pelotaX = 10, pelotaY = 100, pelota2X = 230, pelota2Y = 100, jug1X = 10, jug1Y = 100, jug2X = 230, jug2Y = 100; 
Thread hilo; 
int derecha = 5;// to the right 
int izquierda = -5; // to the left 
int arriba = 5; // upward 
int abajo = -5; // down 
int ancho, alto; // Width and height of the ball 
int ancho2, alto2; 
// Scores 
int contPlay1 = 0, contPlay2 = 0; 
boolean player1FlagArr, player1FlagAba, player2FlagArr, player2FlagAba; 
boolean juego, gameOver; 

public PanelPelota() { 
    juego = true; 
    hilo = new Thread(this); 
    hilo.start(); 
} 

// Draw ball and ships 
public void paintComponent(Graphics gc) { 
    setOpaque(false); 
    super.paintComponent(gc); 

    // Draw ball 
    gc.setColor(Color.black); 
    gc.fillOval(pelotaX, pelotaY, 8, 8); 
    gc.fillOval(pelota2X, pelota2Y, 8, 8); 

    // Draw ships 
    gc.fillRect(jug1X, jug1Y, 10, 25); 
    gc.fillRect(jug2X, jug2Y, 10, 25); 

    // Draw scores 
    gc.drawString("Jugador1: " + contPlay1, 25, 10); 
    gc.drawString("Jugador2: " + contPlay2, 150, 10); 

    if (gameOver) { 
     //gc.drawString("Game Over", 100, 125); 
     Restart replay = new Restart(); 
     JPanel midPanel = new JPanel(); 
     replay.setVisible(true); 
     if(contPlay1 == 6) 
      midPanel.add(new JLabel("Player1 wins!")); 
     if(contPlay2 == 6) 
      midPanel.add(new JLabel("Player2 wins!")); 
     replay.setTitle("Game Over!"); 
     replay.setSize(300, 100); 
     replay.setLocationRelativeTo(null); 

     midPanel.add(new JLabel("")); 
     replay.add(midPanel, BorderLayout.CENTER); 
     replay.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    } 
} 

// Positions on X and Y for the ball 
public void dibujarPelota(int nx, int ny) { 
    pelotaX = nx; 
    pelotaY = ny; 
    this.ancho = this.getWidth(); 
    this.alto = this.getHeight(); 
    repaint(); 
} 

public void dibujarPelota2(int nx, int ny) { 
    pelotaX = nx; 
    pelotaY = ny; 
    this.ancho2 = this.getWidth(); 
    this.alto2 = this.getHeight(); 
    repaint(); 
} 

// Here we receive from the game container class the key pressed 
public void keyPressed(KeyEvent evt) { 
    switch (evt.getKeyCode()) { 
    // Move ship 1 
    case KeyEvent.VK_W: 
     player1FlagArr = true; 
     break; 
    case KeyEvent.VK_S: 
     player1FlagAba = true; 
     break; 

    // Move ship 2 
    case KeyEvent.VK_UP: 
     player2FlagArr = true; 
     break; 
    case KeyEvent.VK_DOWN: 
     player2FlagAba = true; 
     break; 
    } 
} 

// Here we receive from the game container class the key released 
public void keyReleased(KeyEvent evt) { 
    switch (evt.getKeyCode()) { 
    // Mover Nave1 
    case KeyEvent.VK_W: 
     player1FlagArr = false; 
     break; 
    case KeyEvent.VK_S: 
     player1FlagAba = false; 
     break; 

    // Mover nave 2 
    case KeyEvent.VK_UP: 
     player2FlagArr = false; 
     break; 
    case KeyEvent.VK_DOWN: 
     player2FlagAba = false; 
     break; 
    } 
} 

// Move player 1 
public void moverPlayer1() { 
    if (player1FlagArr == true && jug1Y >= 0) 
     jug1Y += abajo; 
    if (player1FlagAba == true && jug1Y <= (this.getHeight() - 25)) 
     jug1Y += arriba; 
    dibujarPlayer1(jug1X, jug1Y); 
} 

// Move player 2 
public void moverPlayer2() { 
    if (player2FlagArr == true && jug2Y >= 0) 
     jug2Y += abajo; 
    if (player2FlagAba == true && jug2Y <= (this.getHeight() - 25)) 
     jug2Y += arriba; 
    dibujarPlayer2(jug2X, jug2Y); 
} 

// Position on Y for the player 1 
public void dibujarPlayer1(int x, int y) { 
    this.jug1X = x; 
    this.jug1Y = y; 
    repaint(); 
} 

// Position on Y for the player 2 
public void dibujarPlayer2(int x, int y) { 
    this.jug2X = x; 
    this.jug2Y = y; 
    repaint(); 
} 

public void run() { 
    // TODO Auto-generated method stub 
    boolean izqDer = false; 
    boolean arrAba = false; 
    boolean izqDer2 = false; 
    boolean arrAba2 = false; 

    while (true) { 

     if (juego) { 

      // The ball move from left to right 
      if (izqDer) { 
       // a la derecha 
       pelotaX += derecha; 
       if (pelotaX >= (ancho - 8)) 
        izqDer = false; 
      } else { 
       // a la izquierda 
       pelotaX += izquierda; 
       if (pelotaX <= 0) 
        izqDer = true; 
      } 

      // The ball moves from up to down 
      if (arrAba) { 
       // hacia arriba 
       pelotaY += arriba; 
       if (pelotaY >= (alto - 8)) 
        arrAba = false; 

      } else { 
       // hacia abajo 
       pelotaY += abajo; 
       if (pelotaY <= 0) 
        arrAba = true; 
      } 
      dibujarPelota(pelotaX, pelotaY); 

      // The second ball move from left to right 
      if (izqDer2) { 
       // a la derecha 
       pelota2X += derecha; 
       if (pelota2X >= (ancho - 8)) 
        izqDer2 = false; 
      } else { 
       // a la izquierda 
       pelota2X += izquierda; 
       if (pelota2X <= 0) 
        izqDer2 = true; 
      } 

      // The ball moves from up to down 
      if (arrAba2) { 
       // hacia arriba 
       pelota2Y += arriba; 
       if (pelota2Y >= (alto - 8)) 
        arrAba2 = false; 

      } else { 
       // hacia abajo 
       pelota2Y += abajo; 
       if (pelota2Y <= 0) 
        arrAba2 = true; 
      } 
      dibujarPelota2(pelota2X, pelota2Y); 

      // Delay 
      try { 
       Thread.sleep(50); 
      } catch (InterruptedException ex) { 

      } 

      // Move player 1 
      moverPlayer1(); 

      // Move player 2 
      moverPlayer2(); 

      // The score of the player 1 increase 
      if (pelotaX >= (ancho - 8)) 
       contPlay1++; 

      // The score of the player 2 increase 
      if (pelotaX == 0) 
       contPlay2++; 

      // Game over. Here you can change 6 to any value 
      // When the score reach to the value, the game will end 
      if (contPlay1 == 6 || contPlay2 == 6) { 
       juego = false; 
       gameOver = true; 
      } 

      // The ball stroke with the player 1 
      if (pelotaX == jug1X + 10 && pelotaY >= jug1Y && pelotaY <= (jug1Y + 25)) 
       izqDer = true; 

      // The ball stroke with the player 2 
      if (pelotaX == (jug2X - 5) && pelotaY >= jug2Y && pelotaY <= (jug2Y + 25)) 
       izqDer = false; 

      // The ball2 stroke with the player 1 
      if (pelota2X == jug1X + 10 && pelota2Y >= jug1Y && pelota2Y <= (jug1Y + 25)) 
       izqDer2 = true; 

      // The ball2 stroke with the player 2 
      if (pelota2X == (jug2X - 5) && pelota2Y >= jug2Y && pelota2Y <= (jug2Y + 25)) 
       izqDer2 = false; 
     } 
    } 
} 
} 

再起動クラス

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 

public class Restart extends JFrame{ 
private static final long serialVersionUID = 1L; 

public JButton restart = new JButton("Restart"); 

public Restart() { 
    Container cp = getContentPane(); 
    cp.setLayout(new BorderLayout()); 

    JPanel bottomPanel = new JPanel(); 
    bottomPanel.add(restart); 
    cp.add(bottomPanel, BorderLayout.SOUTH); 

    restart.addActionListener(new ActionListener() { 

      public void actionPerformed(ActionEvent e) { 
      //Creating the window with all its awesome snaky features 
      Main thisClass= new Main(); 
      thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
      thisClass.setVisible(true); 

      //Close Menu once select 
      String cmd = e.getActionCommand(); 
      if(cmd.equals("Restart")) 
      { 
       dispose(); 
      } 
      }; 
     }); 
} 
} 

：ここでは、コードです問題。

ありがとうございます。

Answer 1

dibujarPelotaおよびdibujarPelota2は同じインスタンスフィールドに値を割り当て、効果的にオーバーライドします。

public void dibujarPelota(int nx, int ny) { 
    pelotaX = nx; 
    pelotaY = ny; 
    this.ancho = this.getWidth(); 
    this.alto = this.getHeight(); 
    repaint(); 
} 

public void dibujarPelota2(int nx, int ny) { 
    pelotaX = nx; 
    pelotaY = ny; 
    this.ancho2 = this.getWidth(); 
    this.alto2 = this.getHeight(); 
    repaint(); 
} 

はい、あなたの2番目のボールは更新され、ペイントされましたが、最初のボールと同じ場所にあります。

変更dibujarPelota2それはUIが依存している状態情報を更新していますので、あなたが使用している例は、最良の例ではないことに注意して、nxpelota2Xとnyにも

public void dibujarPelota2(int nx, int ny) { 
    pelota2X = nx; 
    pelota2Y = ny; 
    this.ancho2 = this.getWidth(); 
    this.alto2 = this.getHeight(); 
    repaint(); 
} 

pelota2Yを割り当てますEDTの文脈の外に出て、それは軽微な問題でしかないかもしれませんが、それはすぐにエスカレートすることができます