java - 如何在 JPanel 上显示多个图像？

Question

我一直在努力解决这个问题，但我似乎无法解决。

我想在同一个 JPanel 的屏幕上显示多个图像，但由于某种原因，它只显示来自 paint 组件的最后一个图像

我正在尝试制作水果忍者风格的游戏，并希望在动画发生之前将水果从框架中抽出。

有没有人知道如何做到这一点？任何帮助将不胜感激...

import javax.swing.*;//imports JPanel class
import java.awt.*;//imports the Graphics class

public class FruitNinja extends JPanel {

   private Image dojo;
   private Image apple;
   private Image orange;
   private Image pineapple;
   private Image strawberry;
   private Image banana;

   private Timer timer;
   private int x, y;

   public FruitNinja() { // a constructor to set up graphics windo
      super();
      setBackground(Color.WHITE);
      loadImage();
      x = 25;
      y = 25;


   }



   private void loadImage() {
      ImageIcon ii = new ImageIcon("Dojo.jpg");
      dojo = ii.getImage();

      ImageIcon oo = new ImageIcon("Orange.ico");
      orange = oo.getImage();

      ImageIcon ss = new ImageIcon("Strawberry.png");
      strawberry = ss.getImage();

      ImageIcon bb = new ImageIcon("Banana.png");
      banana = bb.getImage();

      ImageIcon pp = new ImageIcon("Pineapple.png");
      pineapple = pp.getImage();

      ImageIcon aa = new ImageIcon("Apple.png");
      apple = aa.getImage();


   }

   public void paintComponent(Graphics g){ // draw graphics in the panel

      super.paintComponent(g);// to make panel display correctly
      g.drawImage(dojo, 0,0, this);
      //draws out dojo


      super.paintComponent(g);// to make panel display correctly
      g.drawImage(apple, 0,0, this);

      super.paintComponent(g);// to make panel display correctly
      g.drawImage(orange, 0,0, this);

      super.paintComponent(g);// to make panel display correctly
      g.drawImage(pineapple, 0,0, this);

      super.paintComponent(g);// to make panel display correctly
      g.drawImage(banana, 0,0, this);

      super.paintComponent(g);// to make panel display correctly
      g.drawImage(strawberry, 0,0, this);

      //draws out the fruits somewhere
   }

  /* 
   @Override
    public void actionPerformed(ActionEvent e) {

      x += 5;
      y += 5;

      if (y > getHeight()) {
         y = 25;
         x = 25;
      }
      repaint();
   }
*/

   public static void main(String[] args) { 

      FruitNinja panel = new FruitNinja(); // window for drawing  
      JFrame f = new JFrame(); // the program itself
      f.setTitle("Fruit Ninja");
      f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//when the X button is clicked, the program quits
      f.setSize(1280,800);//size of the frame
      Container pane = f.getContentPane();//pane refers to the interior of the JFrame

      FruitNinja p1 = new FruitNinja();

      pane.add(p1);//add the FacePanel object to the interior of the frame
      f.setVisible(true);

   }
}

也与当前问题无关，因为我正在尝试制作一个类似游戏的 FruitNinja，我该如何制作它以便代码注册我的鼠标在那里(所以它在切水果时我的鼠标悬停在水果上)？是 mouseListenter 吗？

Answer 1

我建议看看 Painting in AWT and Swing了解您遇到问题的原因

paintComponent 的工作之一是为组件的绘制准备Graphics 上下文，它通常通过用组件的背景色填充它来完成此操作

因此根据您的代码，这表明您只需要在方法开始时调用一次 paintComponent

public void paintComponent(Graphics g){ // draw graphics in the panel

  super.paintComponent(g);// to make panel display correctly
  g.drawImage(dojo, 0,0, this);
  //draws out dojo
  g.drawImage(apple, 0,0, this);
  g.drawImage(orange, 0,0, this);
  g.drawImage(pineapple, 0,0, this);
  g.drawImage(banana, 0,0, this);
  g.drawImage(strawberry, 0,0, this);
  //draws out the fruits somewhere
}

所以，现在所有的图像都应该在彼此之上绘制

Also unrelated to this current question, since I'm trying to make a FruitNinja game, how do I make it so the code registers that my mouse is there(so it slices the fruit when my mouse hovers over the fruit)? is it mouseListenter?

您可能正在寻找一个MouseMotionListener，看看How to Write a Mouse Listener了解更多详情