mycomput.java

根据上课老师的要求

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
 class Mycomput extends Frame 
{
	TextField text1,text2,text3;
	Label lab1,lab2,lab3;
	Button ad,sub,milt,div,but;
	public Mycomput()
	{       super("简单计算器");
                setLayout(new FlowLayout());
		setSize(300,200);
                setVisible(true);
		GridBagLayout gbl=new GridBagLayout();
		setLayout(gbl);
		lab1=new Label("操作数:");
		add(lab1);
		text1=new TextField(10);
		text1.addActionListener(new koActionListener());
		add(text1);
		lab2=new Label("操作数:");
		add(lab2);
		text2=new TextField(10);
		text2.addActionListener(new koActionListener());
		add(text2);
		lab3=new Label("结果:");
		add(lab3);
		text3=new TextField(10);
		text3.addActionListener(new koActionListener());
		add(text3);
		ad=new Button("加");
		sub=new Button("减");
		milt=new Button("乘");
		div=new Button("除");
		but=new Button("退出");
		add(ad);
		ad.addActionListener(new koActionListener());
		add(sub);
		sub.addActionListener(new koActionListener());
		add(milt);
		milt.addActionListener(new koActionListener());
		add(div);
		div.addActionListener(new koActionListener());
		add(but);		
                but.addActionListener(new koActionListener());
                addWindowListener(new koWindowListener());
}	
 class koActionListener implements ActionListener
 {public void actionPerformed(ActionEvent e)
  {double d;
   int align=FlowLayout.LEFT;
   String ko=e.getActionCommand();
   if(ko.equals(ad.getLabel())){
   align=FlowLayout.LEFT;
   double i,j;
   i=Double.valueOf(text1.getText()).doubleValue();
   j=Double.valueOf(text2.getText()).doubleValue();
   d=i+j;
  text3.setText(String.valueOf(d));
   }
  else if(ko.equals(sub.getLabel())){
  align=FlowLayout.CENTER;
  double i,j;
  i=Double.valueOf(text1.getText()).doubleValue();
  j=Double.valueOf(text2.getText()).doubleValue();
  d=i-j;
  text3.setText(String.valueOf(d));}
 else if(ko.equals(milt.getLabel())){
 align=FlowLayout.RIGHT;
 double i,j;
 i=Double.valueOf(text1.getText()).doubleValue();
 j=Double.valueOf(text2.getText()).doubleValue();
 d=i*j;
 text3.setText(String.valueOf(d));
  }
else if(ko.equals(div.getLabel())){
align=FlowLayout.RIGHT;
double i,j;
i=Double.valueOf(text1.getText()).doubleValue();
j=Double.valueOf(text2.getText()).doubleValue();
d=i/j; text3.setText(String.valueOf(d));
}
else if(ko.equals(but.getLabel()))
{System.exit(0);}}}
class koWindowListener extends WindowAdapter
{public void windowClosing(WindowEvent e)
 {e.getWindow().dispose();
  System.exit(0);
  }}
  public static void main(String args[])
  {new Mycomput();}}