keylistener Java:Pacman不会移动到KeyType上

Question

问题：我无法通过左右箭头键移动可怜的pacman。我基本上是在尝试使用“差异”作为x坐标，在x坐标中，pacman是围绕这个坐标设计的；如果“差异”被更改，pacman将移动。 如果有人能为这项光荣的“吃豆人”游戏提供一些启示，那将是一件好事。我更喜欢一个简单的解决方案，而不是重新设计整个代码；我是新来的

主要内容：

    public class Benyt {
    public static void main(String[] args)
    {
        JFrame vindue = new JFrame ("Eksamensspil");
        vindue.add(new Pacman());
        vindue.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        vindue.setSize(317,540);
        vindue.setVisible(true);
        Graphics g = vindue.getGraphics();
        Bold bold = new Bold(g, 125, 400);
    }
}

pacman类：

package eksamensspil;

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*; //
import java.awt.Graphics;
import java.awt.event.*;

public class Pacman  extends JPanel implements KeyListener 
{
    GeneralPath pacman;
    GeneralPath bane;
    int difference = 0;

    // constructor
    public Pacman()
    {
       tegnPacman();
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
       g2.draw(bane);
       g2.drawString("Point: ", 230, 470);
       g2.draw(pacman);       
    }    

    //keytyped
            public void keyTyped(KeyEvent e)
    {
       tegnPacman();
        if (e.getKeyCode() == KeyEvent.VK_LEFT) 
            difference = difference - 6;
        else if (e.getKeyCode() == KeyEvent.VK_RIGHT) 
            difference = difference + 6;
        repaint();
    }

   private void tegnPacman()
   {


        setBackground(Color.WHITE);

        // Koordinaterne defineres herunder
        // Koordinater

        int baneX = 300;
        int baneY = 500;

        // Pacman:
        int pacmanCenterX = 150+difference;
        int pacmanCenterY = 425;        
        // ======================PACMAN======================
        pacman = new GeneralPath ();

        //Der tegnes en hvid rektangel for at "overwrite" den gamle pacman
//        BasicStroke stregtype = new BasicStroke(2, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND);
        pacman.append(new Rectangle2D.Float(0, 400, 300, 50), false);

        // pacman-figuren 
        pacman.append(new Arc2D.Float(pacmanCenterX-25, pacmanCenterY-25, 50, 50, 45 , -270 , Arc2D.PIE), false);

        // Øjet tegnes
        pacman.append(new Ellipse2D.Float(pacmanCenterX-15, pacmanCenterY-7, 4, 4), false);     

        // VENSTRE PIL
        pacman.append(new Line2D.Float(pacmanCenterX-25, pacmanCenterY, pacmanCenterX-50, pacmanCenterY), false);
        pacman.append(new Line2D.Float(pacmanCenterX-50, pacmanCenterY, pacmanCenterX-45, pacmanCenterY-5), false);
        pacman.append(new Line2D.Float(pacmanCenterX-50, pacmanCenterY, pacmanCenterX-45, pacmanCenterY+5), false);

        // HØJRE PIL
        pacman.append(new Line2D.Float(pacmanCenterX+25, pacmanCenterY, pacmanCenterX+50, pacmanCenterY), false);
        pacman.append(new Line2D.Float(pacmanCenterX+50, pacmanCenterY, pacmanCenterX+45, pacmanCenterY-5), false);
        pacman.append(new Line2D.Float(pacmanCenterX+50, pacmanCenterY, pacmanCenterX+45, pacmanCenterY+5), false);

        // =====================BANEN=========================
        bane = new GeneralPath ();

        //Banens rammer
        bane.append(new Rectangle2D.Float(0,0,300,500), false);

        //linje som afgrænser banen
        bane.append(new Line2D.Float(0, baneY-50, baneX, baneY-50), false);

        //Pointbox
        bane.append(new Rectangle2D.Float(225, baneY-25, 75, 25), false);        

   }

    public void keyPressed(KeyEvent e) // Krav for at KeyListener virker, ellers ubenyttet
    {}
    public void keyReleased(KeyEvent e) // Krav for at KeyListener virker, ellers ubenyttet
    {}
    }

Answer 1

看起来你没有注册你的KeyListener。必须在setBackground(Color.WHITE);之后的tegnPacman()方法中添加以下行：

setBackground(Color.WHITE); 
addKeyListener(this); // add this line. 

这会将密钥侦听器添加到JFrame，从而触发事件