Java JLabel图像阵列

我试图将同一个jlabel存储的图像加载到gridlayout面板中两次，但是，该图像只显示一次，然后移动，而不是创建两个图像实例

如何将碎片数组中的相同JLabel位置存储到boardLabels数组中的多个JLabel中

谢谢：）

这很有效

    boardLabels[0] = new JLabel(pieces[1]);
    boardLabels[1] = new JLabel(pieces[1]);

使用ImageIcons时，我希望避免这种情况，因为要更新主板，我必须先卸下然后重新加载JLabel。我更愿意只更新已经加载的标签

编辑 我以前尝试过这个，但是它抛出了一个空指针异常

    boardLabels[0].setIcon(pieces[1]);
    boardLabels[1].setIcon(pieces[1]);

    boardPanel.add(boardLabels[0]);
    boardPanel.add(boardLabels[1]);

---

不要这样做，因为不能将同一组件多次添加到可视化容器中。最好使用多个JLabel，但让它们使用相同的ImageIcon。图像图标可以方便地多次使用：

public MainFrame() {
    pieceIcon[0] = new ImageIcon(System.getProperty("user.dir") + 
        "/images/piece1.png");
    pieceIcon[1] = new ImageIcon(System.getProperty("user.dir") + 
        "/images/piece2.png");

    this.add(boardPanel);
    displayGUIboard();
}


public void displayGUIboard() {
    boardPanel.add(new JLabel(pieceIcon[0]);
    boardPanel.add(new JLabel(pieceIcon[0]);
}

顺便说一下：请注意，所有变量都不应该是静态的

编辑：关于您最近的编辑：

这很有效

使用ImageIcons时，我希望避免这种情况，因为要更新主板，我必须先卸下然后重新加载JLabel。我更愿意只更新已加载的标签。”

解决方案
不，您根本不需要更改JLabel。将JLabel保留在原来的位置，只需使用JLabel

setIcon（…）

方法交换它们保留的图标即可

编辑
此外，不要将变量与对象混淆。即使创建了一组JLabel变量，如果它们都引用同一个JLabel对象，也不能将JLabel对象多次添加到容器中

编辑您声明：

---

代码是游戏显示功能的一部分。整数数组将代表解释的棋盘（但不在上述代码中）正确的Jlabel图像将被放置在gridlayout面板中，以显示电路板的gui。我已使显示代码正常工作，但在我的当前版本中，它将从电路板上删除Jlabel，然后创建新的Jlabel（件…）…但我更希望它从整数数组中更新自身，而不是删除标签，读取数组，然后重新创建标签

因此，创建一个使用GridLayout的JPanel，并用不变的JLabel填充它。然后，只需根据int数组中的值更改JLabel中的图标。您可以创建一个方法来简化和自动化此过程

编辑关于：

我以前尝试过编辑，但它引发了空指针异常

然后像解决任何NPE一样解决这个问题。找出哪一行抛出NPE，检查该行上的变量，至少有一个为null，然后修复它，以便在尝试使用它之前初始化变量

编辑
例如：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;

import javax.swing.*;

@SuppressWarnings("serial")
public class GridExample extends JPanel {
   public static final int[][] MAP = {
      {1, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 0, 0, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 1, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
      {1, 1, 0, 0, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
      {1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 2},
      {1, 1, 1, 1, 1, 0, 0, 0, 2, 2, 2},
      {1, 1, 1, 1, 1, 1, 0, 0, 0, 2, 2}
   };

   public static final Color[] COLORS = {};
   private JLabel[][] labelGrid = new JLabel[MAP.length][MAP[0].length];

   public GridExample() {
      setLayout(new GridLayout(MAP.length, MAP[0].length));
      for (int r = 0; r < labelGrid.length; r++) {
         for (int c = 0; c < labelGrid[r].length; c++) {
            labelGrid[r][c] = new JLabel();
            labelGrid[r][c].setIcon(Ground.getGround(MAP[r][c]).getIcon());
            add(labelGrid[r][c]);            
         }
      }
   }

   private static void createAndShowGui() {
      GridExample mainPanel = new GridExample();

      JFrame frame = new JFrame("GridExample");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

enum Ground {
   DIRT(0, new Color(205,133, 63)), GRASS(1, new Color(0, 107, 60)), 
   WATER(2, new Color(29, 172, 214));
   private int value;
   private Color color;
   private Icon icon;

   private Ground(int value, Color color) {
      this.value = value;
      this.color = color;

      icon = createIcon(color);
   }

   private Icon createIcon(Color color) {
      int width = 24; // how to use const in enum? 
      BufferedImage img = new BufferedImage(width, width, BufferedImage.TYPE_INT_ARGB);
      Graphics g = img.getGraphics();
      g.setColor(color);
      g.fillRect(0, 0, width, width);
      g.dispose();
      return new ImageIcon(img);
   }

   public int getValue() {
      return value;
   }

   public Color getColor() {
      return color;
   }

   public Icon getIcon() {
      return icon;
   }

   public static Ground getGround(int value) {
      for (Ground ground : Ground.values()) {
         if (ground.getValue() == value) {
            return ground;
         }
      }
      return null;
   }

}

导入java.awt.Color；
导入java.awt.Graphics；
导入java.awt.GridLayout；
导入java.awt.image.buffereImage；
导入javax.swing.*；
@抑制警告（“串行”）
公共类GridExample扩展了JPanel{
公共静态最终整数[][]映射={
{1, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2},
{1, 1, 0, 0, 2, 2, 2, 2, 2, 2, 2},
{1, 1, 1, 0, 2, 2, 2, 2, 2, 2, 2},
{1, 1, 1, 0, 0, 2, 2, 2, 2, 2, 2},
{1, 1, 1, 1, 0, 2, 2, 2, 2, 2, 2},
{1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
{1, 1, 0, 0, 0, 2, 2, 2, 2, 2, 2},
{1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
{1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 2},
{1, 1, 1, 1, 1, 0, 0, 0, 2, 2, 2},
{1, 1, 1, 1, 1, 1, 0, 0, 0, 2, 2}
};
公共静态最终颜色[]颜色={}；
私有JLabel[]labelGrid=newjlabel[MAP.length][MAP[0.length]；
公共网格示例（）{
setLayout（新的GridLayout（MAP.length，MAP[0].length））；
for（int r=0；r

其中显示一个GUI网格：

---

为了进行比较，我对@HFOE进行了重新分解，以便

Ground实现图标

并对

values（）

返回的数组进行索引。由于

value

是一个实现细节，

int[][]MAP

可以改为

Ground[]MAP

更新：此变体说明了

Ground[]
boardLabels[0] = new JLabel(pieces[1]);
boardLabels[1] = new JLabel(pieces[1]);

import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;

import javax.swing.*;

@SuppressWarnings("serial")
public class GridExample extends JPanel {
   public static final int[][] MAP = {
      {1, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 0, 0, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 2, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 1, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
      {1, 1, 0, 0, 0, 2, 2, 2, 2, 2, 2},
      {1, 1, 1, 0, 0, 0, 2, 2, 2, 2, 2},
      {1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 2},
      {1, 1, 1, 1, 1, 0, 0, 0, 2, 2, 2},
      {1, 1, 1, 1, 1, 1, 0, 0, 0, 2, 2}
   };

   public static final Color[] COLORS = {};
   private JLabel[][] labelGrid = new JLabel[MAP.length][MAP[0].length];

   public GridExample() {
      setLayout(new GridLayout(MAP.length, MAP[0].length));
      for (int r = 0; r < labelGrid.length; r++) {
         for (int c = 0; c < labelGrid[r].length; c++) {
            labelGrid[r][c] = new JLabel();
            labelGrid[r][c].setIcon(Ground.getGround(MAP[r][c]).getIcon());
            add(labelGrid[r][c]);            
         }
      }
   }

   private static void createAndShowGui() {
      GridExample mainPanel = new GridExample();

      JFrame frame = new JFrame("GridExample");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

enum Ground {
   DIRT(0, new Color(205,133, 63)), GRASS(1, new Color(0, 107, 60)), 
   WATER(2, new Color(29, 172, 214));
   private int value;
   private Color color;
   private Icon icon;

   private Ground(int value, Color color) {
      this.value = value;
      this.color = color;

      icon = createIcon(color);
   }

   private Icon createIcon(Color color) {
      int width = 24; // how to use const in enum? 
      BufferedImage img = new BufferedImage(width, width, BufferedImage.TYPE_INT_ARGB);
      Graphics g = img.getGraphics();
      g.setColor(color);
      g.fillRect(0, 0, width, width);
      g.dispose();
      return new ImageIcon(img);
   }

   public int getValue() {
      return value;
   }

   public Color getColor() {
      return color;
   }

   public Icon getIcon() {
      return icon;
   }

   public static Ground getGround(int value) {
      for (Ground ground : Ground.values()) {
         if (ground.getValue() == value) {
            return ground;
         }
      }
      return null;
   }

}

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.TexturePaint;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.*;

/** @see https://stackoverflow.com/a/11556441/230513 */
public class GridExample extends JPanel {

    public static final Ground[][] MAP = {
        {Ground.GRASS, Ground.GRASS, Ground.DIRT, Ground.WATER, Ground.WATER},
        {Ground.GRASS, Ground.DIRT, Ground.CITY, Ground.WATER, Ground.WATER},
        {Ground.GRASS, Ground.DIRT, Ground.CITY, Ground.WATER, Ground.WATER},
        {Ground.GRASS, Ground.DIRT, Ground.DIRT, Ground.DIRT, Ground.WATER},
        {Ground.GRASS, Ground.GRASS, Ground.DIRT, Ground.WATER, Ground.WATER},
    };
    private JLabel[][] labelGrid = new JLabel[MAP.length][MAP[0].length];

    public GridExample() {
        setLayout(new GridLayout(MAP.length, MAP[0].length));
        for (int r = 0; r < labelGrid.length; r++) {
            for (int c = 0; c < labelGrid[r].length; c++) {
                labelGrid[r][c] = new JLabel();
                labelGrid[r][c].setIcon(MAP[r][c]);
                add(labelGrid[r][c]);
            }
        }
    }

    private static void createAndShowGui() {
        GridExample mainPanel = new GridExample();
        JFrame frame = new JFrame("GridExample");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowGui();
            }
        });
    }
}

enum Ground implements Icon {

    DIRT(new Color(205, 133, 63)), GRASS(new Color(0, 107, 60)),
    WATER(new Color(29, 172, 214)), CITY(Color.lightGray);
    private static final int SIZE = 42;
    private Random random = new Random();
    private TexturePaint paint;

    private Ground(Color color) {
        this.paint = initPaint(color);
    }

    private TexturePaint initPaint(Color color) {
        BufferedImage image = new BufferedImage(
            SIZE, SIZE, BufferedImage.TYPE_INT_ARGB);
        Rectangle2D.Double rect = new Rectangle2D.Double(0, 0, SIZE, SIZE);
        for (int row = 0; row < SIZE; row++) {
            for (int col = 0; col < SIZE; col++) {
                if (random.nextBoolean()) {
                    image.setRGB(col, row, color.getRGB());
                } else {
                    if (random.nextBoolean()) {
                        image.setRGB(col, row, color.darker().getRGB());
                    } else {
                        image.setRGB(col, row, color.brighter().getRGB());
                    }
                }
            }
        }
        return new TexturePaint(image, rect);
    }

    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        Graphics2D g2d = (Graphics2D) g;
        g2d.setPaint(paint);
        g.fillRect(0, 0, SIZE, SIZE);
    }

    @Override
    public int getIconWidth() {
        return SIZE;
    }

    @Override
    public int getIconHeight() {
        return SIZE;
    }
}