关于java图形界面的问题:为什么运行后我的程序不能正常显示应该显示的界面
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Test {
public static void main(String[] args) {
CalculatorJFrame fa = new CalculatorJFrame();
fa.setDefaultCloseOperation(fa.EXIT_ON_CLOSE);
fa.setVisible(true);
}
}
class CalculatorJFrame extends JFrame
{
public CalculatorJFrame()
{
setSize(400,400);
CalculatorJPanel pa = new CalculatorJPanel();
add(pa);
//pack();
}
}
class CalculatorJPanel extends JPanel
{
private JButton display;
private JPanel panel;
public void CalculatorJPanel()
{
setLayout(new BorderLayout());
display = new JButton("0");
add(display,BorderLayout.NORTH);
panel = new JPanel();
panel.setLayout(new GridLayout(4,4));
addButton("7");
addButton("8");
addButton("9");
addButton("/");
addButton("4");
addButton("5");
addButton("6");
addButton("*");
addButton("1");
addButton("2");
addButton("3");
addButton("-");
addButton("0");
addButton(".");
addButton("=");
addButton("+");
add(panel,BorderLayout.CENTER);
}
private void addButton(String label)
{
JButton button = new JButton(label);
panel.add(button);
}
}