两个数在按下按钮时相加,用消息框显示和数
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Caculator extends JFrame implements ActionListener{
 /**
  * @param args
  */
 public Caculator(){
  super("计算");
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  JTextField num0=new JTextField(5);
  JTextField num1=new JTextField(5);
  JButton button=new JButton("计算");
  JPanel p=new JPanel();
  //num0.setEditable(true);
  //num1.setEditable(true);
  button.addActionListener(this);
  
  p.add(num0);
  p.add(num1);
  p.add(button);
  setContentPane(p);
  pack();
  setVisible(true);
  
 }
 public static void main(String[] args) {
  // TODO Auto-generated method stub
      Caculator cl=new Caculator();
 }
    
 public void actionPerformed(ActionEvent evt) {
  // TODO Auto-generated method stub
   int sum=Integer.parseInt(num0.getText())+Integer.parseInt(num1.getText()); //这里总是提示
                                                                                 num0,num1 can  not be solved,为什么啊?
         JOptionPane.showMessageDialog(null,sum+""); 
   }
}

 
											





 
	    