从JPanel中添加/删除

Question

我正在尝试制作一个基本地图，其中按下按钮可移动一个字符。 我正在使用Netbeans，并且到目前为止它进展顺利！除了试图从JPanel中删除JLabel，然后添加一个新的JLabel。

这里是我的全码：

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

public class startMap extends JFrame { 

public int locX = 1; 
public int locY = 1; 
ImageIcon tile = new ImageIcon("src/tile.png"); 
JLabel tileLabel = new JLabel(tile); 
ImageIcon berry = new ImageIcon("src/berry.png"); 
JLabel berryLabel = new JLabel(berry); 
ImageIcon blank = new ImageIcon("src/blank.png"); 
JLabel blankLabel = new JLabel(blank); 
JLabel testL = new JLabel("LOL"); 
JPanel[][] map = new JPanel[7][7]; 

public startMap() { 
    setBackground(Color.BLACK); 
    setFocusable(true); 
    keyHandler kh = new keyHandler(); 
    addKeyListener(kh); 
    mapGUI(); 
} 

public void mapGUI() { 
    JPanel mainP = new JPanel(); 
    mainP.setBackground(Color.BLACK); 
    mainP.setLayout(new FlowLayout()); 
    for (int x = 0; x < 7; x++) { 
     for (int i = 0; i < 7; i++) { 
      map[x][i] = new JPanel(); 
      System.out.println("1"); 
      blankLabel = new JLabel(blank); 
      map[x][i].setBorder(BorderFactory.createLineBorder(Color.BLACK, 2)); 
      map[x][i].add(blankLabel); 
     } 
    } 
    for (int x = 1; x < 6; x++) { 
     for (int i = 1; i < 6; i++) { 
      System.out.println("2"); 
      map[x][i].removeAll(); 
      revalidate(); 
      repaint(); 
      tileLabel = new JLabel(tile); 
      map[x][i].add(tileLabel); 
      revalidate(); 
      repaint(); 
     } 
    } 
    System.out.println("3"); 
    map[locX][locY].removeAll(); 
    revalidate(); 
    repaint(); 
    map[locX][locY].add(berryLabel); 
    revalidate(); 
    repaint(); 
    for (int x = 0; x < 7; x++) { 
     for (int i = 0; i < 7; i++) { 
      mainP.add(map[x][i]); 
     } 
    } 

    add(mainP); 
} 

@Override 
public void paint(Graphics g) { 
    super.paint(g); 

} 

private class keyHandler extends KeyAdapter { 

    @Override 
    public void keyPressed(KeyEvent e) { 
     if (e.getKeyCode() == KeyEvent.VK_RIGHT) { 
      locY+=1; 
      map[locX][locY].removeAll(); 
      revalidate(); 
      repaint(); 
      map[locX][locY].add(berryLabel); 
      revalidate(); 
      repaint(); 


     } 

    } 
} 

}

这里是当用户点击右键有什么变化的平方。

这里是KeyAdapter代码：

private class keyHandler extends KeyAdapter { 

    @Override 
    public void keyPressed(KeyEvent e) { 
     if (e.getKeyCode() == KeyEvent.VK_RIGHT) { 
      locY+=1; 
      map[locX][locY].removeAll(); 
      revalidate(); 
      repaint(); 
      map[locX][locY].add(berryLabel); 
      revalidate(); 
      repaint(); 



     } 

    }} 

注：系统出刚刚调试方法，我用它来检查什么被称为时。

所以，当我运行它看起来像这样

向右移动并重新验证$重绘：

为什么位于1,1箱子去是灰色的？

帮助搞清楚如何使箱子保持白色正方形而不是变回灰色。

---------------------------- SSCCE ----------------- -----------------

使用完整的代码上面 ，这是主类：

import javax.swing.*; 

public class TestGame extends JFrame { 

public static void main(String[] args) { 
    startMap sm = new startMap(); 
    sm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    sm.setVisible(true); 
    sm.setSize(380,415); 
    sm.setResizable(false); 
} 
} 

修正版本：

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

public class startMap extends JFrame { 

public int locX = 1; 
public int locY = 1; 
ImageIcon tile = new ImageIcon("src/tile.png"); 
JLabel tileLabel = new JLabel(tile); 
ImageIcon berry = new ImageIcon("src/berry.png"); 
JLabel berryLabel = new JLabel(berry); 
ImageIcon blank = new ImageIcon("src/blank.png"); 
JLabel blankLabel = new JLabel(blank); 
JLabel testL = new JLabel("LOL"); 
JPanel[][] map = new JPanel[7][7]; 

public startMap() { 
    setBackground(Color.BLACK); 
    setFocusable(true); 
    keyHandler kh = new keyHandler(); 
    addKeyListener(kh); 
    mapGUI(); 
} 

public void mapGUI() { 
    JPanel mainP = new JPanel(); 
    mainP.setBackground(Color.BLACK); 
    mainP.setLayout(new FlowLayout()); 
    for (int x = 0; x < 7; x++) { 
     for (int i = 0; i < 7; i++) { 
      map[x][i] = new JPanel(); 
      System.out.println("1"); 
      blankLabel = new JLabel(blank); 
      map[x][i].setBorder(BorderFactory.createLineBorder(Color.BLACK, 2)); 
      map[x][i].add(blankLabel); 
     } 
    } 
    for (int x = 1; x < 6; x++) { 
     for (int i = 1; i < 6; i++) { 
      System.out.println("2"); 
      map[x][i].removeAll(); 
      tileLabel = new JLabel(tile); 
      map[x][i].add(tileLabel); 
      revalidate(); 
      repaint(); 
     } 
    } 
    System.out.println("3"); 
    map[locX][locY].removeAll(); 
    map[locX][locY].add(berryLabel); 
    revalidate(); 
    repaint(); 
    for (int x = 0; x < 7; x++) { 
     for (int i = 0; i < 7; i++) { 
      mainP.add(map[x][i]); 
     } 
    } 

    add(mainP); 
} 

@Override 
public void paint(Graphics g) { 
    super.paint(g); 

} 

private class keyHandler extends KeyAdapter { 

    @Override 
    public void keyPressed(KeyEvent e) { 
     if (e.getKeyCode() == KeyEvent.VK_RIGHT) { 
      berryLabel = new JLabel(berry); //THIS 
      tileLabel = new JLabel(tile); //And THIS had to be RE initialized idk why. 
      map[locX][locY].removeAll(); 
      map[locX][locY].add(tileLabel); 

      locY += 1; 
      map[locX][locY].removeAll(); 
      map[locX][locY].add(berryLabel); 
      revalidate(); 
      repaint(); 


     } 

    } 
} 

}

Answer 1

应该在添加/除去

revalidate(); 
repaint(); 

不要paint()