java 计算器

 

import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;

import javax.swing.*;

public class Calculator5 extends JFrame implements ActionListener
{
    /**
     *
     */
    private static final long serialVersionUID = 1L;
    //private JTextArea text_area;
    JButton but[],enter;
    public enum MyOperator{ADD, SUB, MUL, DIV}
    private MyOperator oper;
    private JTextField text_area;
    private double result, last;
    private HelpDialog viewdialog, helpdialog;
    private int flag, enterflag;
    public Calculator5()
    {
        super("Calculator5");
        this.setResizable(false);
        this.setBounds(300, 240, 240, 340);
        this.setDefaultCloseOperation(3);
        text_area = new JTextField("0");
        text_area.setEditable(false);


        Dimension mini_size  = new Dimension(1000,40);
        text_area.setPreferredSize(mini_size);
        System.out.println("tr"+text_area.getSize().width+"tr"+text_area.getHeight());

        text_area.setFont(new Font("Consolas", 0, 25));//"Default", Font.bold, 20
        text_area.setHorizontalAlignment(JTextField.RIGHT);
        this.getContentPane().add(text_area, BorderLayout.NORTH);

        JPanel jpanel = new JPanel();

        jpanel.setLayout(new FlowLayout(FlowLayout.CENTER,5,7));

        this.getContentPane().add(jpanel);

        String b[] = {"√", "+/-", "C", "+", "7", "8", "9", "-", "4", "5", "6",
                   //  0     1     2    3    4    5    6    7    8    9    10
                "*", "1", "2", "3", "/", "0", "."};
               //11   12   13  14    15   16  17
        but = new JButton[b.length];

        for(int i = 0; i<b.length; i++)
        {
            but[i] = new JButton(b[i]);
            Dimension same_size  = new Dimension(50,40);
            but[i].setPreferredSize(same_size);
            but[i].addActionListener(this);
            jpanel.add(but[i]);
        }
        enter= new JButton("=");
        Dimension same_size  = new Dimension(106,40);
        enter.setPreferredSize(same_size);
        enter.addActionListener(this);
        jpanel.add(enter);

        addmiiMenu();

        this.setVisible(true);
        helpdialog = new HelpDialog(this, "关于产品", 320, 150);
        viewdialog = new HelpDialog(this, "使用说明", 320, 300);
    }
    public void addmiiMenu()
    {
        JMenuBar menubar = new JMenuBar();
        this.setJMenuBar(menubar);

        String menustr[] = {"查看", "文件", "帮助(F1)"};
        JMenu menu[] = new JMenu[menustr.length];
        for(int i = 0; i<menustr.length; i++)
        {
            menu[i] = new JMenu(menustr[i]);
            menubar.add(menu[i]);
        }
        JMenuItem menu_help_view = new JMenuItem("查看帮助  ");
        menu_help_view.addActionListener(this);
        menu_help_view.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F1, InputEvent.CTRL_MASK));
        JMenuItem menu_help_about = new JMenuItem("关于计算器");
        menu_help_about.addActionListener(this);
        menu[2].add(menu_help_view);
        menu[2].addSeparator();
        menu[2].add(menu_help_about);
        menu[2].setMnemonic(KeyEvent.VK_F1);

    }
    public static void main(String args[])
    {
        new Calculator5();
    }
    private class HelpDialog extends JDialog
    {
        /**
         *
         */
        private static final long serialVersionUID = 1L;
        JFrame jframe;
        JTextArea jtexr;
        HelpDialog(JFrame jframe, String st, int wid, int hig)
        {
            super(jframe,st,true);
            this.jframe=jframe;                //
            this.setSize(wid,hig);
            jtexr = new JTextArea("");
            jtexr.setEditable(false);
            jtexr.setFont(new Font("仿宋", 1, 15));
            jtexr.setLineWrap(true);
            //jtexr.setEnabled(false);
            this.getContentPane().add(jtexr);
            this.setDefaultCloseOperation(HIDE_ON_CLOSE);
        }
        void show (String message)
        {
            jtexr.setText(message);
            this.setLocation(jframe.getX()+100,jframe.getY()+100);
            this.setVisible(true);
        }
    }
    @Override

    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub

        DecimalFormat df = new DecimalFormat("#########.#########");
        if(e.getSource()instanceof JMenuItem)                    //MenuItem
        {
            if(e.getActionCommand()=="查看帮助  ")
                viewdialog.show("可以使用计算器进行如加、减、乘、除这样简单的运算。" +
                        "/n/n" +
                        "单击“查看”菜单，然后单击所需模式。" +
                        "/n/n" +
                        "切换模式时，将清除当前的计算。但会保留“记忆钥匙”所存储的计算历史记录和数字。" +
                        "/n/n" +
                        "单击计算器键进行所需的计算");
            if(e.getActionCommand()=="关于计算器")
                helpdialog.show("/n/n    All rights reserved by " +
                        "/n       Mr Baoning Gai" +
                        "/n         11/16/2010");
        }
        if(e.getSource()instanceof JButton)
        {

            if(e.getSource()==but[4])
            {
                Addnumber(7);
            }
            if(e.getSource()==but[5])
            {
                Addnumber(8);
            }
            if(e.getSource()==but[6])
            {
                Addnumber(9);
            }
            if(e.getSource()==but[8])
            {
                Addnumber(4);
            }
            if(e.getSource()==but[9])
            {
                Addnumber(5);
            }
            if(e.getSource()==but[10])
            {
                Addnumber(6);
            }
            if(e.getSource()==but[12])
            {
                Addnumber(1);
            }
            if(e.getSource()==but[13])
            {
                Addnumber(2);
            }
            if(e.getSource()==but[14])
            {
                Addnumber(3);
            }
            if(e.getSource()==but[16])
            {
                Addnumber(0);
            }
            if(e.getSource()==but[17])                     //not complement
            {
                try
                {
                    Integer.parseInt(text_area.getText());
                    flag = 1;
                }
                catch(NumberFormatException nfe)
                {
                    System.out.println("!");
                }
                finally{}
            }
            if(e.getSource()==but[3])                     //not complement
            {
                enterflag = 0;
                oper = MyOperator.ADD;
                result = Double.parseDouble( text_area.getText() );
                text_area.setText("0");
            }
            if(e.getSource()==but[7])                     //not complement
            {
                enterflag = 0;
                oper = MyOperator.SUB;
                result = Double.parseDouble( text_area.getText() );
                text_area.setText("0");
            }
            if(e.getSource()==but[11])                     //not complement
            {
                enterflag = 0;
                oper = MyOperator.MUL;
                result = Double.parseDouble( text_area.getText() );
                text_area.setText("0");
            }
            if(e.getSource()==but[15])                     //not complement
            {
                enterflag = 0;
                oper = MyOperator.DIV;
                result = Double.parseDouble( text_area.getText() );
                text_area.setText("0");
            }
            if(e.getSource()==but[0])                     //求根
            {
                double a = Double.parseDouble( text_area.getText() );
                a = Math.sqrt(a);
                String str = "" + df.format(a);
                text_area.setText(str);
                result = Double.parseDouble( text_area.getText() );
                enterflag = 1;
            }
            if(e.getSource()==but[1])                     //not complement
            {
                double a = Double.parseDouble( text_area.getText() );
                a = 0 - a;
                String str = "" + df.format(a);
                text_area.setText(str);
                result = Double.parseDouble( text_area.getText() );
            }
            if(e.getSource()==but[2])                     //not complement
            {
                text_area.setText("0");
                oper = null;
                result = 0;
                enterflag = 0;
            }
            if(e.getSource()==enter&&oper!=null)                     // complement
            {
                Operate();
                enterflag = 1;
            }
            System.out.print(" result="+result);//NOY
            System.out.print(" last="+last);//NOY
            System.out.print(" flag="+flag);//NOY
            System.out.print(" enterflag="+enterflag);//NOYenterflag
            System.out.println(oper);         //NOY
        }
    }
    public void Addnumber(int getnumber)
    {
        DecimalFormat df = new DecimalFormat("#########.#########");
        String str;
        if(enterflag==1)
        {
            str = "0";
            enterflag = 0;
            oper = null;
        }
        else
        {
            str = text_area.getText();
        }
        if(flag==1)
        {
            str += ".";
            flag = 0;
        }
            str =str+getnumber;
    double input = Double.parseDouble( str );
    str = "" + df.format(input);
    last = input;
    text_area.setText(str);
    System.out.println(input);
    System.out.println(str);
    }
    public void Operate()
    {
        DecimalFormat df = new DecimalFormat("#########.#########");
        System.out.println("clik enter");//NOY
          double b = last;
          double a = result;
            switch(oper)
            {
            case ADD :a = a+b; break;
            case SUB :a = a-b; break;
            case MUL :a = a*b; break;
            case DIV :a = a/b; break;
            }
            result = a;
            String str = "" + df.format(result);
            text_area.setText(str);
    }
}