mycomput1.java

根据上课老师的要求

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
 class Mycomput1 extends Frame implements  ActionListener,ItemListener
{
	TextField text1,text2,text3;
	Label lab1,lab2,lab3;
	Button ad,sub,milt,div,but;
	public Mycomput1()
	{
		super("简单计算器");
		setSize(300,200);
	}
	public void init()
	{
		GridBagLayout gbl=new GridBagLayout();
		setLayout(gbl);
		lab1=new Label("操作数:");
		add(lab1);
		text1=new TextField(30);
		text1.addActionListener(this);
		add(text1);
		lab2=new Label("操作数:");
		add(lab2);
		text2=new TextField(30);
		text2.addActionListener(this);
		add(text2);
		lab3=new Label("结果:");
		add(lab3);
		text3=new TextField(30);
		text3.addActionListener(this);
		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(this);
		add(sub);
		sub.addActionListener(this);
                add(milt);
		milt.addActionListener(this);
		add(div);
		div.addActionListener(this);
		add(but);
		but.addActionListener(this);
                addWindowListener(new koWindowListener());

	}
	public void itemStateChanged(ItemEvent e)
	{
	}
	public void actionPerformed(ActionEvent e)
	{    double d;
	int align=FlowLayout.LEFT;
         if(e.getSource()==ad)
		{    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));
             }
    if(e.getSource()==sub)
		{ 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));
      }
 if(e.getSource()==milt)
		{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));
      }
	  if(e.getSource()==div)
		{
			 double i,j;
			 i=Double.valueOf(text1.getText()).doubleValue();
			 j=Double.valueOf(text2.getText()).doubleValue();
			 d=i/j;
			 text3.setText(String.valueOf(d));
      }

        if(e.getSource()==but)
		{
			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 Mycomput1();}
}