checkboxevt.java

java练习程序

import java.applet.*;
import java.awt.*;
import java.awt.event.*;

class Tompanel1 extends Panel
{
	Checkbox box1,box2,box3;
	CheckboxGroup one;
	Tompanel1()
	{
		setLayout(new GridLayout(1,3));
		one=new CheckboxGroup();
		box1=new Checkbox("北京牌电视",false,one);
		box2=new Checkbox("上海牌电视",false,one);
		box3=new Checkbox("大连牌电视",false,one);
		add(box1);add(box2);add(box3);
	}
}

class Tompanel2 extends Panel
{
	Button Btn1,Btn2,Btn3;
	Tompanel2()
	{
		setLayout(new GridLayout(1,3));
		Btn1=new Button("购买1台");
		Btn2=new Button("购买2台");
		Btn3=new Button("购买3台");
		add(Btn1);add(Btn2);add(Btn3);
	}
}

public class CheckboxEVT extends Applet implements ItemListener, ActionListener
{
	Tompanel1 panel1;
	Tompanel2 panel2;
	Label Label1,Label2;
	TextArea text1,text2;
	GridLayout net;
	public void init()
	{
		net=new GridLayout(3,2);
		setLayout(net);
		panel1=new Tompanel1();
		panel2=new Tompanel2();
		Label1=new Label("产品介绍",Label.CENTER);
		Label2=new Label("产品价格",Label.CENTER);
		text1=new TextArea();
		text2=new TextArea();
		add(Label1);add(Label2);
		add(panel1);add(panel2);
		add(text1);add(text2);
		panel1.box1.addItemListener(this);
		panel1.box2.addItemListener(this);
		panel1.box3.addItemListener(this);
		panel2.Btn1.addActionListener(this);
		panel2.Btn2.addActionListener(this);
		panel2.Btn3.addActionListener(this);
	}
	public void itemStateChanged(ItemEvent e)
	{
		if(e.getItemSelectable()==panel1.box1)
		{
			text1.setText("北京生产");
		}
		else if(e.getItemSelectable()==panel1.box2)
		{
			text1.setText("上海生产");
		}
		else if(e.getItemSelectable()==panel1.box3)
		{
			text1.setText("大连生产");
		}
	}
	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource()==panel2.Btn1)
		{
			text2.setText("北京:1000元,上海:1200元,大连:1100元");
		}
		else if(e.getSource()==panel2.Btn2)
		{
			text2.setText("北京:900元,上海:1100元,大连:1100元");
		}
		else if(e.getSource()==panel2.Btn3)
		{
			text2.setText("北京:800元,上海:1000元,大连:1000元");
		}
	}
}