问题描述
我做了一个大的水色方块，但是不知何故，我的JPanel中出现了一个灰色的小方块，看起来像这样。
中间有一个灰色的小方块，我没有画出来。如何避免呢？这是我的代码：
我的主：
package Main;
public class main {
public static void main(String[] args) {
createWindow window = new createWindow();
}
}
myFrame和myPanel：
package Main;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import Objects.Piece;
public class createWindow extends JFrame {
public myPanel panel;
public createWindow() {
super();
panel = new myPanel();
KeyListener key = new KeyListener() {
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keypressed(KeyEvent e) {
}
@Override
public void keyreleased(KeyEvent e) {
keyAction(e.getKeyCode());
}
public void keyAction(int keycode) {
switch (keycode) {
case KeyEvent.VK_UP:
System.out.println("Up");
break;
case KeyEvent.VK_RIGHT:
System.out.println("Right");
break;
case KeyEvent.VK_DOWN:
System.out.println("Down");
break;
case KeyEvent.VK_LEFT:
System.out.println("Left");
break;
}
}
};
pack();
add(panel);
addKeyListener(key);
setSize(800,450);
setResizable(false);
setLocationRelativeto(null);
setVisible(true);
}
}
class myPanel extends JPanel {
public Piece firstP = new Piece(100,100,new Color(50,255,255),"self");
myPanel() {
super();
setBackground(Color.gray);
add(firstP);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
g2d.setColor(firstP.color);
g2d.fillRect(firstP.x,firstP.y,firstP.width,firstP.height);
}
}
myPiece：
package Objects;
import java.awt.*;
import javax.swing.*;
public class Piece extends JPanel {
public int x;
public int y;
public int width;
public int height;
public Color color;
public String type;
public Piece(int x,int y,int width,int height,Color color,String type) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.color = color;
this.type = type;
}
}
有人可以修复我的代码吗？我是java绘画的新手，在这里看不到错误...
解决方法
如果删除显示“ add（firstP）;”的行，则灰色小方框消失。