我已经绘制了一个图表并在其中放置了一个 20*20 像素的框,我试图用一堆按钮来移动框。问题是,我似乎无法从动作侦听器中更改框的 X 轴和 Y 轴值。这是我的第一个图形应用程序,帮助!
GrapMain.java
import java.awt.BorderLayout;
import javax.swing.JFrame;
import java.awt.Color;
import javax.swing.JTextField;
public class GraphMain {
public static void main(String [] args){
Display nashDisplay = new Display();
nashDisplay.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
图.java
import java.awt.*;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Graph extends JPanel {
int x = 5, y = 100;
Graph (int x, int y){
this.x = x;
this.y = y;
}
public void paintComponent(Graphics g){
super.paintComponent(g);
this.setBackground(Color.WHITE);
//horizontal lines
g.setColor(Color.RED);
for (int height=20; height<200; height+=20){
g.drawLine(5, height, 480, height);
}
//verticle lines
g.setColor(Color.RED);
for (int height=5; height<400; height+=20){
g.drawLine(height,200,height,10);
}
//the box
g.setColor(Color.BLACK);
g.fillRect(this.x, this.y, 20, 20);
//g.fillRect((+20 to move right one box),(+20 to move down one box), 20, 20);
//g.fillRect((-20 to move left one box),(-20 to move up one box), 20, 20);
}
}
显示.java
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class Display extends JFrame {
int X = 5, Y = 100;
private JButton left, right, up, down;
Graph dude = new Graph(X, Y);
public Display() {
super("nash's graph(moving the box!)");
JButton left = new JButton("move left");
add(left, BorderLayout.WEST);
left.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
X = X - 20;
}
});
JButton right = new JButton("move right");
add(right, BorderLayout.EAST);
right.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
X = X + 20;
}
});
JButton up = new JButton("move up");
add(up, BorderLayout.NORTH);
up.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
Y = Y - 20;
}
});
JButton down = new JButton("move down");
add(down, BorderLayout.SOUTH);
down.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
Y = Y + 20;
}
});
setSize(500, 300);
setVisible(true);
add(dude, BorderLayout.CENTER);
}
}