我想在JPanel(Java)上获取ImageIcon的当前位置

时间:2016-08-22 20:11:56

标签: java swing jpanel keyevent imageicon

我想获取图像的坐标,以便我可以相对于坐标更改JPanel的背景颜色。这是我到目前为止所拥有的。代码允许用户向上,向下,向右和向左移动箭头,因此如果箭头是第一象限,背景应为红色,如果箭头移动到第二象限,背景颜色变为绿色,依此类推

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

public class DirectionPanel extends JPanel
{
   private final int X = 200;
   private Point point = null;

   private final int WIDTH = 400, HEIGHT = 200;
   private final int JUMP = 10;  // increment for image movement

   private final int IMAGE_SIZE = 31;

   private ImageIcon up, down, right, left, currentImage;
   private int x, y;

   //-----------------------------------------------------------------
   //  Constructor: Sets up this panel and loads the images.
   //-----------------------------------------------------------------
   public DirectionPanel()
   {
      addKeyListener (new DirectionListener());

      x = WIDTH / 2;
      y = HEIGHT / 2;

      up = new ImageIcon ("arrowUp.gif");
      down = new ImageIcon ("arrowDown.gif");
      left = new ImageIcon ("arrowLeft.gif");
      right = new ImageIcon ("arrowRight.gif");

      currentImage = right;

      setBackground (Color.black);
      setPreferredSize (new Dimension(WIDTH, HEIGHT));
      setFocusable(true);
   }

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

   //*****************************************************************
   //  Represents the listener for keyboard activity.
   //*****************************************************************
   private class DirectionListener implements KeyListener
   {
      //--------------------------------------------------------------
      //  Responds to the user pressing arrow keys by adjusting the
      //  image and image location accordingly.
      //--------------------------------------------------------------
      public void keyPressed (KeyEvent event)
      {
         switch (event.getKeyCode())
         {
            case KeyEvent.VK_UP:
                currentImage = up;
                y -= JUMP;
                break;
            case KeyEvent.VK_DOWN:
                currentImage = down;
                y += JUMP;
                break;
            case KeyEvent.VK_LEFT:
                currentImage = left;
                x -= JUMP;
                break;
            case KeyEvent.VK_RIGHT:
                currentImage = right;
                x += JUMP;
                break;
         }

         point = ???????

         if(point.x < 200 && point.y < 100)
         {
            setBackground(Color.red);
         }
         else if(point.x < 200 && point.y > 100)
         {
            setBackground(Color.green);
         }
         else if(point.y > 100 && point.x > 200)
         {
            setBackground(Color.cyan);
         }
         else if(point.y < 100 && point.x > 200)
         {
            setBackground(Color.yellow);
         }

         repaint();
      }

      //--------------------------------------------------------------
      //  Provide empty definitions for unused event methods.
      //--------------------------------------------------------------
      public void keyTyped (KeyEvent event) {}
      public void keyReleased (KeyEvent event) {}
   }
}

1 个答案:

答案 0 :(得分:3)

您使用变量:&#34; x&#34;和&#34; y&#34;绘制图像,使这些变量成为JPanel中图像的坐标。

您可以将您的观点设置为:

TimeinMinutes

现在,当您更新&#34; x&#34;和&#34; y&#34;该点也将更新,背景将根据您的规格绘制。

我希望它有所帮助!