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我无法创建一个正方形的动画，当按下其中一个箭头键时，该动画将以一定的速度移动。我已经实现了 keyPressed 和 actionPerformed 方法，并且还在构造函数的末尾启动了计时器的滴答声。但是方块仍然不会移动。我做错了什么？

下面是JPanel。

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

public class A3JPanel extends JPanel implements KeyListener, ActionListener{
public static final int JFRAME_AREA_WIDTH = A3Constants.JFRAME_AREA_WIDTH;
public static final int JFRAME_AREA_HEIGHT = A3Constants.JFRAME_AREA_HEIGHT;;

public static final Rectangle HOME_AREA = A3Constants.HOME_AREA;
public static final Rectangle LEO_LEFT_AREA = A3Constants.LEO_LEFT_AREA;
public static final Rectangle ALL_WALLS_AREA = A3Constants.ALL_WALLS_AREA;
public static final Rectangle EXITING_SLIDES_AREA = A3Constants.EXITING_SLIDES_AREA;

public static final Color NICE_GRAY_COLOUR = A3Constants.NICE_GRAY_COLOUR;
public static final Color GAME_SCREEN_COLOUR = A3Constants.GAME_SCREEN_COLOUR;
public static final Color SLIDES_AREA_COLOUR = A3Constants.SLIDES_AREA_COLOUR;
public static final Color LEO_AREA_COLOUR = A3Constants.LEO_AREA_COLOUR; 
public static final Color HOME_AREA_COLOUR = A3Constants.HOME_AREA_COLOUR;
public static final Color WALL_COLOUR = A3Constants.WALL_COLOUR;

public static final int MAX_WALLS = A3Constants.MAX_WALLS;

public static final Font TINY_FONT = A3Constants.TINY_FONT;
public static final Font LARGE_FONT = A3Constants.LARGE_FONT;
public static final Font HUGE_FONT = A3Constants.HUGE_FONT;

public static final int LARGE_FONT_SIZE = A3Constants.LARGE_FONT_SIZE;
public static final int HUGE_FONT_SIZE = A3Constants.HUGE_FONT_SIZE;

public static final Point TICKS_POSITION = A3Constants.TICKS_POSITION;
public static final Point WINNER_LOSER_INFO_POSITION = A3Constants.WINNER_LOSER_INFO_POSITION;  
public static final Point INFORMATION_POSITION1 = A3Constants.INFORMATION_POSITION1;
public static final Point INFORMATION_POSITION2 = A3Constants.INFORMATION_POSITION2;
public static final Point INFORMATION_POSITION3 = A3Constants.INFORMATION_POSITION3;

public static final int TICKS_ALLOWED = A3Constants.TICKS_ALLOWED; 
public static final int UP = A3Constants.UP;
public static final int DOWN = A3Constants.DOWN;
public static final int LEFT = A3Constants.LEFT;
public static final int RIGHT = A3Constants.RIGHT;

private CoolCat coolCat;
private Timer t;

public A3JPanel() {
    setBackground(Color.GREEN);
    coolCat = new CoolCat(A3Constants.LEO_START_AREA.x, A3Constants.LEO_START_AREA.y);
    addKeyListener(this);
    t = new Timer(30,this);
    t.start();
    //t.addActionListener(this);

}

public void paintComponent(Graphics g){
    super.paintComponent(g);
    drawGameArea(g);
    coolCat.draw(g);
}

private void drawGameArea(Graphics g){
    g.setColor(A3Constants.LEO_AREA_COLOUR);
    g.fillRect(A3Constants.LEO_LEFT_AREA.x, A3Constants.LEO_LEFT_AREA.y, A3Constants.LEO_LEFT_AREA.width, A3Constants.LEO_LEFT_AREA.height);
    g.setColor(A3Constants.WALL_COLOUR);
    g.fillRect(A3Constants.ALL_WALLS_AREA.x, A3Constants.ALL_WALLS_AREA.y, A3Constants.ALL_WALLS_AREA.width, A3Constants.ALL_WALLS_AREA.height);
    g.setColor(A3Constants.HOME_AREA_COLOUR);
    g.fillRect(A3Constants.HOME_AREA.x, A3Constants.HOME_AREA.y, A3Constants.HOME_AREA.width, A3Constants.HOME_AREA.height);

}

public void keyPressed(KeyEvent e){
    if(e.getKeyCode() == KeyEvent.VK_UP){
        coolCat.setDirection(A3Constants.UP);
    }
    if(e.getKeyCode() == KeyEvent.VK_DOWN){
        coolCat.setDirection(A3Constants.DOWN);
    }
    if(e.getKeyCode() == KeyEvent.VK_LEFT){
        coolCat.setDirection(A3Constants.LEFT);
    }
    if(e.getKeyCode() == KeyEvent.VK_RIGHT){
        coolCat.setDirection(A3Constants.RIGHT);
    }
}

public void keyReleased(KeyEvent e){}
public void keyTyped(KeyEvent e){}


public void actionPerformed(ActionEvent e){
    coolCat.move();
    repaint();
}

}

下面是另一个类。

import java.awt.*;

public class CoolCat {
public static final Rectangle LEO_START_AREA = A3Constants.LEO_START_AREA;

public static final int GAME_SCREEN_AREA_TOP = A3Constants.GAME_SCREEN_AREA_TOP;
public static final int GAME_SCREEN_AREA_BOTTOM = A3Constants.GAME_SCREEN_AREA_BOTTOM;
public static final int GAME_SCREEN_AREA_LEFT = A3Constants.GAME_SCREEN_AREA_LEFT;
public static final int GAME_SCREEN_AREA_RIGHT = A3Constants.GAME_SCREEN_AREA_RIGHT;

public static final int UP = A3Constants.UP;
public static final int DOWN = A3Constants.DOWN;
public static final int LEFT = A3Constants.LEFT;
public static final int RIGHT = A3Constants.RIGHT;

private Rectangle area;
private int speed;
private int direction;

public CoolCat(int x, int y){

    this.speed = speed;
    speed = (int)(Math.random() * (8 - 4 + 1)) + 4;
    area = new Rectangle(A3Constants.LEO_START_AREA.x, A3Constants.LEO_START_AREA.y);
    direction = RIGHT;

}

public Rectangle getArea(){
    area = new Rectangle(LEO_START_AREA.x, LEO_START_AREA.y, LEO_START_AREA.width, LEO_START_AREA.height);
    return area;

}

public void setDirection(int direction){
    this.direction = direction;
}

//public boolean hasReachedHome(Rectangle zhomeArea){}

public void move(){
    if(direction == A3Constants.UP){
        area.y -= speed;
    } else if(direction == A3Constants.DOWN){
        area.y += speed;
    } else if(direction == A3Constants.LEFT){
        area.x -= speed;
    } else if(direction == A3Constants.RIGHT){
        area.x += speed;
    }
}

public void draw(Graphics g){
    g.setColor(Color.RED);
    g.fillOval(A3Constants.LEO_START_AREA.x, A3Constants.LEO_START_AREA.y, A3Constants.LEO_START_AREA.width, A3Constants.LEO_START_AREA.height);
}

}

4

2 回答 2

1

您正在将 KeyListener 添加到 JPanel，这是一个默认情况下无法接受焦点的组件，并且关键侦听器需要焦点才能工作。

一个简单的解决方案是让您的 JPanel 接受焦点，然后请求将焦点赋予它。

更好的解决方案是避免在 Swing 应用程序中使用 KeyListeners，而是使用 Key Bindings（正如之前在类似问题中多次讨论的那样）。例如，请查看：如何在 Java 中聆听按键时使图像移动。

于 2013-10-24T13:56:33.230 回答
0

尝试这样的事情。我刚做的很快，所以请原谅任何错误。

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class g{
    public static void main(String args){
        SwingUtilities.invokeLater(new Runnable(){
            public void run(){
                create();
            }
        });
    }
    public static MyPanel my;
    public static void create(){
        JFrame f = new JFrame("test");
        my = new MyPanel();
        f.add(my);
        f.setSize(1000,1000);
        f.setVisible(true);
        f.addKeyListener(new KeyListener(){
            @Override
            public void keyPressed(KeyEvent e){
                if(e.getKeyCode == 37){ //left
                    my.move(4); //1 = up, 2 = right, 3 = down, 4 = left
                }
                if(e.getKeyCode == 39){ //left
                    my.move(2); //1 = up, 2 = right, 3 = down, 4 = left
                }
                if(e.getKeyCode == 38){ //left
                    my.move(1); //1 = up, 2 = right, 3 = down, 4 = left
                }
                if(e.getKeyCode == 40){ //left
                    my.move(3); //1 = up, 2 = right, 3 = down, 4 = left
                }
            }
            @Override
            public void keyReleased(KeyEvent e){
                //do nothings
            }
            @Override
            public void keyTyed(KeyEvent e){
                //do nothing
            }
        });
    }
}

public class MyPanel extends JPanel implements ActionListener{
    public static Timer time1;
    public Square s;
    public MyPanel(){
        time1 = new Timer(50, this);
        time1.start();
    }
    public void actionPerformed(ActionEvent e){
        repaint();
    }
    public void move(int d){
        if(d == 1){
            s.setY(s.getY()-1);
        }
        if(d == 2){
            s.setX(s.getX() + 1);
        }
        if(d == 3){
            s.setY(s.getY() + 1);
        }
        if(d == 4){
            s.setX(set.getX() - 1);
        }
        repaint();
    }
    public void paintComponent(Graphics g){
        super.paintComponent(g);
        s.paintSquare(g);
    }
}

public class Square{
    public int x;
    public int y;
    public void setX(int xPos){
        this.x = xPos;
    }
    public int getX(){
        return x;
    }
    public void setY(int yPos){
        this.y = yPos;
    }
    public int getY(){
        return y;
    }
    public void paintSquare(Graphics g){
        g.setColor(Color.WHITE);
        g.fillRect(0,0,1000,1000);
        g.setColor(Color.RED);
        g.fillRect(x,y,30,30);
    }
}
于 2013-10-25T00:15:30.837 回答