java 计算器示例源码(入门级)

【实例截图】

【核心代码】

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.*;

import java.awt.*;
import java.io.IOException;

public class CalWin extends JFrame implements ActionListener,ItemListener{
	final int WIN_W=225,WIN_H=320;
	JMenuBar menubar;
	JMenu menuOperate,menuHelp;
	JMenuItem itemHelp,itemAbout,itemBug;
	JTextField text1,text2,text3;
	JPanel panelCommon,panelSuper;
	JRadioButton buttonCommon,buttonSuper;
	BugWin bugwin;
	Cal cal;
	ButtonGroup bg;
	public CalWin(){
		bugwin=new BugWin();
		setTitle("计算器 2.0 beta2");
		menubar=new JMenuBar();
		menuOperate=new JMenu("操作");
		menuHelp=new JMenu("帮助");
		buttonCommon=new JRadioButton("普通版本");
		buttonSuper=new JRadioButton("超级版本");
		itemHelp=new JMenuItem("获取帮助");
		itemAbout=new JMenuItem("关于");
		itemBug=new JMenuItem("报告Bug");
		bg=new ButtonGroup();
		bg.add(buttonCommon);
		bg.add(buttonSuper);
		buttonSuper.setSelected(true);
		menuOperate.add(buttonCommon);
		menuOperate.add(buttonSuper);
		menubar.add(menuOperate);
		menubar.add(menuHelp);
		menuHelp.add(itemHelp);
		menuHelp.add(itemAbout);
		menuHelp.add(itemBug);
		
		this.setJMenuBar(menubar);
		cSuper();
		cCommon();
		cal=new Cal(this);
		text2.addActionListener(this);
		itemHelp.addActionListener(this);
		itemAbout.addActionListener(this);
		buttonSuper.addItemListener(this);
		buttonCommon.addItemListener(this);
		itemBug.addActionListener(this);
		
		if(buttonSuper.isSelected()){
			this.add(panelSuper);
		}
		else{
			this.add(panelCommon);
		}
		double width = Toolkit.getDefaultToolkit().getScreenSize().width;
		double height =Toolkit.getDefaultToolkit().getScreenSize().height;
		setBounds((int)(width-WIN_W)/2,(int)(height-WIN_H)/2,WIN_W,WIN_H);
		validate();
		setResizable(false);
		setVisible(true);
		setDefaultCloseOperation(DISPOSE_ON_CLOSE);
	}
	public void actionPerformed(ActionEvent e) {
		if(e.getSource()==text2){
			cal.getResult();
		}
		else if(e.getSource()==itemHelp){
			JOptionPane.showMessageDialog(this, "既然点了，那就进来留个言吧");
			Runtime rt = Runtime.getRuntime(); 
			try {

				rt.exec("rundll32   url.dll,FileProtocolHandler   "
						  "http://blog.csdn.net/leasystu");

			} catch (IOException ee) {

			}
		}
		else if(e.getSource()==itemAbout){
			JOptionPane.showMessageDialog(this," Java计算器  作者：_EaSy。 http://blog.csdn.net/leasystu","关于计算器",JOptionPane.INFORMATION_MESSAGE);
		}
		else if(e.getSource()==itemBug){
			bugwin.setVisible(true);
			
		}
	}
	
	
	public void itemStateChanged(ItemEvent ee){
		if(buttonSuper==ee.getSource()){
			this.remove(panelCommon);
			this.add(panelSuper,BorderLayout.CENTER);		
			panelSuper.repaint();
		}
		else if(buttonCommon==ee.getItemSelectable()){
			this.remove(panelSuper);
			this.add(panelCommon,BorderLayout.CENTER);
			panelCommon.repaint();
		}
		validate();
	}
	public void cSuper(){
		panelSuper=new JPanel();
		panelSuper.setLayout(null);
		text2=new JTextField(20);
		text2.setBounds(5, 10,200,20);
		text2.setHorizontalAlignment(JTextField.RIGHT);
		text3=new JTextField(10);
		text3.setEditable(false);
		text3.setBackground(new Color(255, 255, 255));
		text3.setHorizontalAlignment(JTextField.RIGHT);
		JLabel label=new JLabel("=");
		label.setBounds(5,40,20,20);
		text3.setBounds(15, 40,180,20);
		JLabel label2=new JLabel("输入式子如：-12 (1 2)*2^2-5/2");
		label2.setBounds(4,70,200,20);
		panelSuper.add(text2);
		panelSuper.add(label);
		panelSuper.add(text3);
		panelSuper.add(label2);
	}
	public void cCommon(){
		panelCommon=new panelCommon(this);
		
	}
	public static void main(String[] args) {
		new CalWin();
	}
	public void f(){
		this.text3.setText("输入有误");
/*		this.panelSuper.validate();
		this.text3.repaint();
		this.text3.validate();
		this.panelSuper.repaint();
		this.panelSuper.validate();
		this.repaint();
		this.validate();
		*/
		System.out.println("执行啦");
	}

}