JLabel在另一个JLabel上不起作用 [英] JLabel over another JLabel not working

问题描述

我一直在为我的Roguelike尝试将JLabel放在另一个JLabel上.不幸的是，它似乎不起作用.到目前为止，这是我的代码:

I've been trying to put a JLabel over another one for my Roguelike. Unfortunaly, it doesn't seems to work. Here's my code so far :

public void updateDraw(int direction){
    int[] pos = Dungeon.getPos();

    for(int i=pos[1]-(DISPLAY_Y_SIZE/2) ; i<pos[1]+(DISPLAY_Y_SIZE/2) ; i++){
        for(int j=pos[0]-(DISPLAY_X_SIZE/2) ; j<pos[0]+(DISPLAY_X_SIZE/2) ; j++){
            labelGrid[i-(pos[1]-(DISPLAY_Y_SIZE/2))][j-(pos[0]-(DISPLAY_X_SIZE/2))].setIcon(tiles[Dungeon.getMapTile(i,j)].getIcon());      
        }
    }

    labelGrid[DISPLAY_Y_SIZE/2][DISPLAY_X_SIZE/2].add(character);

    this.repaint();
}

我已经阅读了一些其他问题的解决方案，而所有这些解决方案都是通过将JLabel添加到另一个解决方案来完成的.它不按这里的预期工作，不知道为什么吗?

I've read some solutions to other problems, and they all do it by simply adding the JLabel to the other one. it doesn't work as intended here, any idea why ?

PS:我不想为我的JPanel使用JLayeredPane.

PS : I don't want to use a JLayeredPane for my JPanel.

推荐答案

一个替代方案

请勿使用组件(即JLabels)创建游戏环境.相反，您可以绘制所有游戏对象.

One Alternative

Don't create your game environment using components (i.e. JLabels). Instead, you can paint all your game objects.

例如，如果您正在执行以下操作:

For instance, if you're doing something like:

JLabel[][] labelGrid = JLabel[][];
...
ImageIcon icon = new ImageIcon(...);
JLabel label = new JLabel(icon);
...
for(... ; ... ; ...) {
   container.add(label);
}

您可以改掉所有标签，也可以使用Images代替ImageIcons，然后可以将所有图像绘制到单个组件表面.也许像这样:

You could instead get rid of the labels all together, and also use Images instead of ImageIcons, then you can just paint all the images to a single component surface. Maybe something like:

public class GamePanel extends JPanel {
    Image[][] images = new Image[size][size];
    // init images

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(image,/*  Crap! How do we know what location? Look Below */);
    }  
}

• 因此，要通过位置(即x和y，哦以及大小)解决此问题，我们可以使用一些好的旧的OOP抽象.创建一个包装图像，位置和尺寸的类.例如

  So to solve this problem with the locations (i.e. the x and y, oh and the size also), we could use some good old OOP abstractions. Create a class that wraps the image, the locations, and sizes. For example

  class LocatedImage {
      private Image image;
      private int x, y, width, height;
      private ImageObserver observer;
  
  
      public LocatedImage(Image image, int x, int y, int width, 
                                       int height, ImageObserver observer) {
          this.image = image;
          ...
      }
  
      public void draw(Graphics2D g2d) {
          g2d.drawImage(image, x, y, width, height, observer);
      }
  }
  

  然后，您可以在面板中使用许多此类的实例.像

  Then you can use a bunch of instances of this class in your panel. Something like

  public class GamePanel extends JPanel {
      List<LocatedImage> imagesToDraw;
      // init images
      // e.g. imagesToDraw.add(new LocatedImage(img, 20, 20, 100, 100, this));
  
      @Override
      protected void paintComponent(Graphics g) {
          super.paintComponent(g);
          Graphics2D g2d = (Graphics2D)g.create();
          for (LocatedImage image: imagesToDraw) {
              image.draw(g2d);
          }
          g2d.dispose();
      }  
  }
  

  一旦您有了这个概念，就有许多不同的可能性.

  Once you have this concept down, there are many different possibilities.

  • 请参考执行自定义绘画关于绘画的想法.
  • Have a look at Performing Custom Painting for some general ideas about painting.

  这篇关于JLabel在另一个JLabel上不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！