Question

我在鼠标点击图片时无法将图片换出。它应该切换到＆＃34; redSmiley.gif＆＃34;当从任何方向在30像素范围内点击图像并切换回＆＃34; happyFace.gif＆＃34;当它再次被点击时。这是我的主要方法。

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

public class Rebound
{
 //-----------------------------------------------------------------
 //  Displays the main frame of the program.
 //-----------------------------------------------------------------
 public static void main (String[] args)
 {
  JFrame frame = new JFrame ("Rebound");
  frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

  frame.getContentPane().add(new ReboundPanel());
  frame.pack();
  frame.setVisible(true);
 }
}

这是我的Panel Class。

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class ReboundPanel extends JPanel
{
private static final long serialVersionUID = 1L;
private final int WIDTH = 300, HEIGHT = 100;
private final int DELAY = 20, IMAGE_SIZE = 35;

private ImageIcon image;
private Timer timer;
private int x, y, moveX, moveY;

//-----------------------------------------------------------------
//  Sets up the panel, including the timer for the animation.
//-----------------------------------------------------------------
public ReboundPanel()
{
  timer = new Timer(DELAY, new ReboundListener());

  image = new ImageIcon (getClass().getResource("happyFace.gif"));

  x = 0;
  y = 40;
  moveX = moveY = 3;

  setPreferredSize (new Dimension(WIDTH, HEIGHT));
  setBackground (Color.black);
  timer.start();
}

//-----------------------------------------------------------------
//  Draws the image in the current location.
//-----------------------------------------------------------------
public void paintComponent (Graphics page)
{
  super.paintComponent (page);
  image.paintIcon (this, page, x, y);
}

//*****************************************************************
//  Represents the action listener for the timer.
//*****************************************************************
private class ReboundListener implements ActionListener
{
  //--------------------------------------------------------------
  //  Updates the position of the image and possibly the direction
  //  of movement whenever the timer fires an action event.
  //--------------------------------------------------------------
  public void actionPerformed (ActionEvent event)
  {
     x += moveX;
     y += moveY;

     if (x <= 0 || x >= WIDTH-IMAGE_SIZE)
        moveX = moveX * -1;

     if (y <= 0 || y >= HEIGHT-IMAGE_SIZE)
        moveY = moveY * -1;

     repaint();
  }
}
class MousePressListener implements MouseListener
{
   public void mousePressed(MouseEvent event)
   {
       if(event.getX() <= 30 && event.getY() <= 30)
       {
           if(event.getX() <= 30 && event.getY() <= 30)
           {
               image = new ImageIcon(getClass().getResource("redSmiley.gif"));
           }
           else
               image = new ImageIcon(getClass().getResource("happyFace.gif")); 
       }
   }
   public void mouseClicked(MouseEvent event) 
   {
       if(event.getX() <= 30 && event.getY() <= 30)
       {
           image = new ImageIcon(getClass().getResource("redSmiley.gif"));
       }
       else
           image = new ImageIcon(getClass().getResource("happyFace.gif"));
   }
   //Empty methods
   public void mouseEntered(MouseEvent arg0) 
   {    
   }
   public void mouseExited(MouseEvent arg0) 
   {    
   }
   public void mouseReleased(MouseEvent arg0)
   {
   }
 }
}

如何在30像素内单击鼠标按钮时交换图像？

Answer 1

您需要知道图像的渲染位置，并且需要将鼠标点与此进行比较...

一种方法是创建一个包含缓冲区的java.awt.Rectangle ...

Rectangle bounds = new Rectangle();
bounds.x = x - 30;
bounds.y = y - 30;
bounds.width = image.getWidth(this) + 60;
bounds.height = image.getHeight(this) + 60;

然后检查鼠标点是否在其边界内......

if (bounds.contains(event.getPoint()) {
    // Did click image...

按钮在30像素内单击后，在两个图像之间转换

1 个答案: