Java中的鼠标单击框架中的图像不新鲜 [英] Image did not fresh in Frame on Mouse Click In Java

问题描述

第一次从三个不同的数组在Jframe上显示三个随机图像. 甚至触发了MouseClicked方法，但图像不会在Frame中刷新. 我想在每次单击框架"时刷新三张随机图像. 请帮助

First Time three random images shown on Jframe from three diffrent arrays. even MouseClicked Method triggered but images does not refresh in Frame. I want to refresh three random images each time i click on Frame. Please help

   import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Random;

import javax.swing.*;

public class Cards extends JFrame implements MouseListener {

    public static void main(String[] args) {
    JFrame frame = new Cards();     
        frame.setTitle("Cards");



        frame.setSize(500, 500);

        frame.setLocationRelativeTo(null);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);


        new Cards();

    }

    public Cards() {

        this.getContentPane().addMouseListener(this);

        cards1();
        cards2();
        cards3();

    }

    public void cards1() {

        ImageIcon[] images = new ImageIcon[10];
        for (int i = 1; i < images.length; i++) {

            images[i] = new ImageIcon("Drawables//Images//" + i + ".png");

        }

        int[] threeRandoms = new int[1];
        Random ran = new Random();

        for (int i = 0; i < threeRandoms.length; i++) {

            threeRandoms[i] = ran.nextInt(10);

        }

        setLayout(new GridLayout(1, 4, 5, 5));

        add(new JLabel(images[threeRandoms[0]]));

    }


    public void cards2() {

        ImageIcon[] images = new ImageIcon[10];
        for (int i = 1; i < images.length; i++) {

            images[i] = new ImageIcon("Drawables//Images1//" + i + ".png");

        }

        int[] threeRandoms = new int[1];
        Random ran = new Random();

        for (int i = 0; i < threeRandoms.length; i++) {

            threeRandoms[i] = ran.nextInt(10);

        }

        setLayout(new GridLayout(1, 4, 5, 5));

        add(new JLabel(images[threeRandoms[0]]));

    }

    public void cards3() {
        // this.getContentPane().addMouseListener(this);
        ImageIcon[] images = new ImageIcon[10];
        for (int i = 1; i < images.length; i++) {

            images[i] = new ImageIcon("Drawables//Images2//" + i + ".png");

        }

        int[] threeRandoms = new int[1];
        Random ran = new Random();

        for (int i = 0; i < threeRandoms.length; i++) {

            threeRandoms[i] = ran.nextInt(10);

        }

        // Labels with gridLayout

        setLayout(new GridLayout(1, 4, 5, 5));

        add(new JLabel(images[threeRandoms[0]]));

    }

    public void mouseClicked(MouseEvent e) {
        System.out.println("The frame was clicked.");
        new Cards();
    }

    public void mouseEntered(MouseEvent e) {
        System.out.println("The mouse entered the frame.");
    }

    public void mouseExited(MouseEvent e) {
        System.out.println("The mouse exited the frame.");

    }

    public void mousePressed(MouseEvent e) {
        System.out.println("The left mouse button was pressed.");

    }

    public void mouseReleased(MouseEvent e) {
        System.out.println("The left mouse button was released.");

    }

}

推荐答案

很抱歉，但是您的代码使我感到困惑.一方面，您的cards1()，cards2()和cards3()方法看起来完全一样，如果是，为什么要使用3种不同的方法?为什么不只是一种方法?在这些方法中，您似乎试图重复添加JLabel.您是否要在GUI中添加许多JLabel?还是只是尝试显示随鼠标动作而随机变化的3张图像?

I'm sorry, but I'm confused by your code. For one thing your cards1(), cards2() and cards3() methods look to be all the very same, and if so, why 3 different methods? Why not just one method? In those methods you appear to be trying to add JLabels repeatedly. Are you trying to add many many JLabels to the GUI? Or are you simply trying to display 3 images that change randomly on mouse action?

我建议对结构进行一些更改:

I would recommend structuring things a bit differently:

• 如果可能，请在类的构造函数中一次读取所有必需的图像，将图像放入ImageIcons中，然后将它们添加到ArrayList或多个ArrayList(如果需要)中.
• 不要在每次发生mouseClick时添加新的JLabel.
• 创建一个JPanel，为其提供GridLayout，并在您的类构造函数中向其中添加三个JLabel，它们是实例字段或在数组或ArrayList中.
• 将此JPanel添加到您的JFrame.
• 向每个JLabel添加一个MouseListener
• ，因为MouseListener的mousePressed(MouseEvent e)方法(不是mouseClicked)会随机分配您的号码，并使用该号码在JLabel源上调用setIcon(...)，该源是通过在MouseEvent参数上调用getSource()获得的.

• If possible, read all necessary images in once in your class's constructor, put the images into ImageIcons and then add them to an ArrayList or several ArrayLists if need be.
• Don't add new JLabels each time a mouseClick occurs.
• Create a JPanel give it a GridLayout and in your class constructor add to it three JLabels that are either instance fields or in an array or ArrayList.
• Add this JPanel to your JFrame.
• Add a MouseListener to each JLabel
• in that MouseListener's mousePressed(MouseEvent e) method (not mouseClicked) randomize your number and use that number to call setIcon(...) on the JLabel source, obtained by calling getSource() on your MouseEvent parameter.

例如:

import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;

@SuppressWarnings("serial")
public class RandomImages extends JPanel {
   private static final int LABEL_COUNT = 3;
   private Random random = new Random();

   public RandomImages() {
      setLayout(new GridLayout(1, 3));
      for (int i = 0; i < LABEL_COUNT; i++) {
         final List<Icon> iconList = new ArrayList<>();

         // TODO: get images for the ith list 
         // and fill iconList with ImageIcons from the first grouping

         // create JLabel and give it the first Icon from the List above
         final JLabel label = new JLabel(iconList.get(0));
         label.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
               // get random number from random object using iconList.size()
               // get random Icon from list
               // set label's icon via setIcon(...)
            }
         });
         // add to GUI
         add(label);
      }
   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("RandomImages");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(new RandomImages());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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

具体示例2:

import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.swing.*;

@SuppressWarnings("serial")
public class RandomChessMen extends JPanel {
   // for this example I get a sprite sheet that holds several sprite images in it
   // the images can be found here: http://stackoverflow.com/questions/19209650
   private static final String IMAGE_PATH = "http://i.stack.imgur.com/memI0.png";
   private static final int LABEL_COUNT = 2;
   private static final int ICON_COLUMNS = 6;
   private Random random = new Random();

   public RandomChessMen() throws IOException {
      URL url = new URL(IMAGE_PATH);
      BufferedImage largeImg = ImageIO.read(url);
      setLayout(new GridLayout(1, 0));

      // break down large image into its constituent sprites and place into ArrayList<Icon>
      int w = largeImg.getWidth() / ICON_COLUMNS;
      int h = largeImg.getHeight() / LABEL_COUNT;
      for (int i = 0; i < LABEL_COUNT; i++) {
         final List<Icon> iconList = new ArrayList<>();
         int y = (i * largeImg.getHeight()) / LABEL_COUNT;
         // get 6 icons out of large image
         for (int j = 0; j < ICON_COLUMNS; j++) {
            int x = (j * largeImg.getWidth()) / ICON_COLUMNS;
            // get subImage
            BufferedImage subImg = largeImg.getSubimage(x, y, w, h);
            // create ImageIcon and add to list
            iconList.add(new ImageIcon(subImg));
         }

         // create JLabel
         final JLabel label = new JLabel("", SwingConstants.CENTER);
         int eb = 40;
         label.setBorder(BorderFactory.createEmptyBorder(eb, eb, eb, eb));

         // get random index for iconList
         int randomIndex = random.nextInt(iconList.size());
         Icon icon = iconList.get(randomIndex); // use index to get random Icon
         label.setIcon(icon); // set label's icon
         label.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
               Icon secondIcon = label.getIcon();
               // so we don't repeat icons
               while (label.getIcon() == secondIcon) {
                  int randomIndex = random.nextInt(iconList.size());
                  secondIcon = iconList.get(randomIndex);
               }
               label.setIcon(secondIcon);
            }
         });
         // add to GUI
         add(label);
      }
   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("RandomImages");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      try {
         frame.getContentPane().add(new RandomChessMen());
      } catch (IOException e) {
         e.printStackTrace();
         System.exit(-1);
      }
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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

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