调试java小程序

名字myFrameEvent3.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class myFrameEvent3 {

private JTextField tf;
private JButton b0;
private String s="";

myFrameEvent3(){
JFrame jf=new JFrame();
tf=new JTextField(20);
b0 = new JButton("0");
jf.setSize(220,180);
b0.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e){
JButton tempB = (JButton)e.getSource();
s = tempB.getLabel();
tf.setText(tf.getText()+s);}
});
Container cp =jf.getContentPane();
cp.add(tf,BorderLayout.NORTH);
cp.add(b0,BorderLayout.CENTER);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.setVisible(true);
}

public static void main(String[] args) {
myFrameEvent1 et=new myFrameEvent1();
}
}

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public static void main(String[] args) {
myFrameEvent3 et = new myFrameEvent3();//改为 '3',而非 '1'
}
请注意给戚帆你源代码里注释掉高败雹枯笑的那行以及它的替换者

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class myFrameEvent3 {
private JTextField tf;
private JButton b0;
private String s = "";

myFrameEvent3() {
JFrame jf = new JFrame();
tf = new JTextField(20);
b0 = new JButton("0");
jf.setSize(220, 180);
b0.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton tempB = (JButton) e.getSource();
//s = tempB.getLabel();
s = tempB.getText();
tf.setText(tf.getText() + s);
}
});
Container cp = jf.getContentPane();
cp.add(tf, BorderLayout.NORTH);
cp.add(b0, BorderLayout.CENTER);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.setVisible(true);
}

public static void main(String[] args) {
myFrameEvent3 et = new myFrameEvent3();
}
}

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main函森哪消数此知的缓清 myFrameEvent1 et=new myFrameEvent1();改成

myFrameEvent3 et = new myFrameEvent3();

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