9.13-cal.java

介绍有关java的资料 课件 相当一本书籍 里面都是很基础的知识

import   java.awt.* ;
import   java.awt.event.* ;
public class Cal implements ActionListener
{
    Frame      f;
    TextField   tf1;
    Button   b1,b2,b3,b4;
    public void display()
   {
      f=new Frame("Calculation");
      f.setSize(260,150);
      f.setLocation(320,240);
      f.setBackground(Color.lightGray);
      f.setLayout(new FlowLayout(FlowLayout.LEFT));
      tf1=new TextField(30);
      tf1.setEditable(false);
      f.add(tf1);
      b1=new Button("1");
      b2=new Button("2");
      b3=new Button("+");
      b4=new Button("C");
      f.add(b1);
      f.add(b2);
      f.add(b3);
      f.add(b4);
      b1.addActionListener(this);
      b2.addActionListener(this);
      b3.addActionListener(this);
      b4.addActionListener(this);
      f.addWindowListener( new WinClose());
      f.setVisible(true);
   }


   public void actionPerformed(ActionEvent e)
   {   
     if(e.getSource()==b4)   
       tf1.setText(" ") ;
     else    
       tf1.setText(tf1.getText()+e.getActionCommand());
   }
   
   public static void main(String arg[])
   {
      (new Cal()).display()  ;
   }

}

class WinClose extends WindowAdapter
{
   public void windowClosing(WindowEvent e)
   {
      System.exit(0) ;   
   }

}