这是文件1(我的导师更喜欢是我们使用单独的文件为每个分机)如何将圆圈移动到“WEST”边框布局框架?
import javax.swing.*;
import java.awt.*;
public class Lab2 extends JFrame {
Lab2(){
setTitle("Lab 1b - Application #2");
Lab2Panel p = new Lab2Panel();
add(p);
}
public static void main(String[] args){
Lab2 frame = new Lab2();
frame.setTitle("Lab2 Application # 1");
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(200, 400);
frame.setVisible(true);
}
}
文件2:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Lab2Panel extends JPanel{
Lab2Button canvas = new Lab2Button();
JPanel panel = new JPanel();
Lab2Panel() {
setLayout(new BorderLayout());
JButton leftButton = new JButton("left");
JButton rightButton = new JButton("right");
JButton upButton = new JButton("up");
JButton downButton = new JButton("down");
panel.add(leftButton);
panel.add(rightButton);
panel.add(upButton);
panel.add(downButton);
this.add(canvas, BorderLayout.CENTER);
this.add(panel, BorderLayout.SOUTH);
leftButton.addActionListener(new Lab2MoveBallListener());
}
}
文件3:
import javax.swing.*;
import java.awt.*;
public class Lab2Button extends JPanel {
int radius = 5;
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.drawOval(getWidth()/2 - radius, getHeight()/2 - radius, 2 * radius, 2 * radius);
}
public void moveLeft(){
this.add(this, BorderLayout.WEST);
this.repaint();
}
}
动作监听代码:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Lab2MoveBallListener implements ActionListener{
public void actionPerformed(ActionEvent e){
this.moveLeft();
}
}
当用户单击“左”按钮时,我正尝试将圆圈移至WEST边框布局。有人能帮助我吗。
不扩展每个类并只扩展actionlistener的原因是什么? – Robert 2012-01-31 02:23:00
比继承更喜欢构图。 *必须*实现'ActionListener',其他可以用其他方式完成。 – 2012-01-31 02:24:53
我不认为我会跟着你。到目前为止,在课堂上我们只创建了这样的类。当我们需要一个按钮时,我们编写一个扩展JButton的类并调用该类的一个实例。 – Robert 2012-01-31 02:28:18