我很难弄清楚如何使清除按钮在整个面板上伸展。我也很难找到如何在面板上方创建显示用户单击的键的部分。请帮忙?这是我到目前为止所拥有的......我试图改变清除按钮的大小,但那部分代码什么都不做。
import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TelephonePanel extends JPanel
{
public TelephonePanel()
{
JPanel panel = new JPanel ();
panel.setLayout(new BorderLayout());
setLayout (new GridLayout (5, 3));
setPreferredSize (new Dimension(300, 400));
JButton b1 = new JButton ("1");
JButton b2 = new JButton ("2");
JButton b3 = new JButton ("3");
JButton b4 = new JButton ("4");
JButton b5 = new JButton ("5");
JButton b6 = new JButton ("6");
JButton b7 = new JButton ("7");
JButton b8 = new JButton ("8");
JButton b9 = new JButton ("9");
JButton ba = new JButton ("*");
JButton b0 = new JButton ("0");
JButton bp = new JButton ("#");
JButton bclear = new JButton ("Clear");
bclear.setSize(new Dimension(300, 100));
add (b1);
add (b2);
add (b3);
add (b4);
add (b5);
add (b6);
add (b7);
add (b8);
add (b9);
add (ba);
add (b0);
add (bp);
add (bclear);
}
}