calculator.java~1~

教材管理系统

package bookmanager;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;


public class CalculateFrame extends JFrame //程序框架继承自JFrame类
{
    private String result = "0";
    private String input = "";
    private String sText = "0";
    private int numOfPoint = 0;
    private int numOfHistoryOperation = 0;
    private String operationOfNow = "";
    private String operationOfPast = "";
    boolean backSpaceLock = true;
    boolean LockOfOperation = true;

    JTextArea help; //帮助
    JScrollPane scrollHelp;


    public    CalculateFrame()
    {
       String[] buttonValue = new String[]{"1","2","3","/","sqrt","4","5","6","*","%","7","8","9",
       "-","1/x","0","+/-",".","+","="};
       Container container = getContentPane();
       final JTextField SText = new JTextField(sText);
       container.setLayout(new BorderLayout());
       operatorButtonListener obtListener = new operatorButtonListener();

       JPanel pButton = new JPanel();
       pButton.setLayout(new GridLayout(4,5));
       JButton[] jbutton = new JButton[20];
       for(int i = 0 ; i <jbutton.length ; i++)
       {
    jbutton[i] = new JButton(buttonValue[i]);
    pButton.add(jbutton[i]);           //添加按钮
    if((i==3||i==4||i==8||i==9)||((i>12)&&(i<=19))&&i!=15)
     jbutton[i].setForeground(new Color(255, 0, 0));
    else
       jbutton[i].setForeground(new Color(0, 0, 255)); //控制按钮字体颜色
    if((i%5)<3&&i<=17)
    {
      jbutton[i].addActionListener(new ActionListener()     //在内部实现监听器的类
      {
     public void actionPerformed(ActionEvent e)
     {
       String s = e.getActionCommand();
       backSpaceLock = true;
       if(numOfPoint>=1 && s.compareTo(".")==0)
      numOfPoint++;
       else
       {
       if(s.equals("."))
         numOfPoint++;
       if(s.equals("+/-"))                     //数字符号的转变实现
         sText = new String(""+(0-Double.parseDouble(SText.getText())));
          else
         if(!sText.equals("0")||sText.equals(".")&&sText.equals("0"))
        sText += s;
         else
        sText = s;
        SText.setText(sText);
       }
     }
      });//end 实现内部监听器
}//end if
else
      if((i+1)%5==0&&i!=19)
             jbutton[i].addActionListener(new ActionListener()
             {
               public void actionPerformed(ActionEvent e)
               {
                     sText = SText.getText();
         String s = e.getActionCommand();
         if(s.equals("sqrt"))
       {
         sText =new String(""+Math.sqrt(Double.parseDouble(sText)));
         SText.setText(sText);
         input = sText;
       }
         else
       if(s.equals("1/x"))
        {
        sText = new String(""+ 1/Double.parseDouble(sText));
        SText.setText(sText);
        input = sText;
                  }
               }//end public
        });    //end else-if
              else
          jbutton[i].addActionListener(new ActionListener()
                 {
                   public void actionPerformed(ActionEvent e)
                   {
                    operationOfNow = e.getActionCommand();
                    input =sText;
                    if(!operationOfNow.equals("="))
                     {
        if(!sText.equals(""))
        {
         SText.setText("0");
         numOfHistoryOperation++;
            if(numOfHistoryOperation > 1)
            result = operation(operationOfPast,result,input);
            else
           if(numOfHistoryOperation == 1 && LockOfOperation)//第一次输入的情况
           {
            result = input;
            LockOfOperation = true;
           }//end if
            sText = "0";
         }//end if
          operationOfPast = operationOfNow;
       } //end if
        else
        {
        result = operation(operationOfPast,result,input);
        LockOfOperation = false;
          numOfHistoryOperation = 0;
        }
      numOfPoint = 0;
      backSpaceLock = false ;
      if(result.equals("Infinity"))
       SText.setText("除数不能为0");
      else
        SText.setText(result);
         }//end public
      });//end jbutton
    }//end for
    JPanel P2 = new JPanel();
    P2.setLayout(new FlowLayout(FlowLayout.RIGHT));
    JButton jbuttonBackSpace = new JButton("BackSpace");
    jbuttonBackSpace.addActionListener(new ActionListener()
    {
      public void actionPerformed(ActionEvent e)
       {
         if(backSpaceLock)
    {
       if(sText.length() <= 1)
     sText = "0";
       else
     sText =sText.substring(0,sText.length()-1);
       SText.setText(sText);
    }
       }
    }); //end jubttonBackSpace
    P2.add(jbuttonBackSpace);
    JButton jbuttonCE = new JButton("CE");
    jbuttonCE.addActionListener(new ActionListener()
    {
        public void actionPerformed(ActionEvent e)
         {
            input = "0";
            SText.setText(input);
         }
    });    //end jbttonCE
    P2.add(jbuttonCE);
     JButton jbuttonC = new JButton("C");
         jbuttonC.addActionListener(new ActionListener()
         {
       public void actionPerformed(ActionEvent e)
       {
        result = "0";
        input = "" ;
        operationOfNow = "" ;
        operationOfPast = "" ;
        sText = "0" ;
        numOfPoint = 0;
        numOfHistoryOperation = 0;
        LockOfOperation = true ;
        SText.setText(sText);
       }
      });
       P2.add(jbuttonC);

    JPanel p = new JPanel();
    p.setLayout(new BorderLayout());
    p.add(pButton,BorderLayout.CENTER);
    p.add(P2,BorderLayout.NORTH);

    JPanel p3 = new JPanel();
    p3.setLayout(new BorderLayout());
    SText.setHorizontalAlignment(JTextField.RIGHT);
    SText.setEditable(false);
    p3.add(SText,BorderLayout.NORTH);
    p3.add(p,BorderLayout.CENTER);

    container.add(p3,BorderLayout.CENTER);

    //增加面板的菜单栏
    JMenuBar mainMenu;
    JMenu editMenu, viewMenu, helpMenu;
    JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, topHelp, aboutCal;

       mainMenu = new JMenuBar();
        editMenu = new JMenu("编辑(E)");
        viewMenu = new JMenu("查看(V)");
        helpMenu = new JMenu("帮助(H)");
        copyItem = new JMenuItem("     复制(C) Ctrl+C");
        pasteItem = new JMenuItem("     粘贴(V) Ctrl+V");
        editMenu.add(copyItem);
        editMenu.add(pasteItem);
        tItem = new JMenuItem("●标准型(T)");
        sItem = new JMenuItem("     科学型(S)");
        numberGroup = new JMenuItem("     数字分组(I)");
        viewMenu.add(tItem);
        viewMenu.add(sItem);
        viewMenu.add(numberGroup);
        topHelp = new JMenuItem("     帮助主题(H)");
        help = new JTextArea(5, 20);
        scrollHelp = new JScrollPane(help);
        help.setEditable(false);
        help.append("执行简单计算\n");
        help.append("1.    键入计算的第一个数字。\n");
        help.append("2.    单击“+”执行加、“-”执行减、“*”执行乘或“/”执行除。\n");
        help.append("3.    键入计算的下一个数字。\n");
        help.append("4.    输入所有剩余的运算符和数字。\n");
        help.append("5.    单击“=”。\n");
        aboutCal = new JMenuItem("     关于计算器(A)");
        helpMenu.add(topHelp);
        helpMenu.add(aboutCal);
        mainMenu.add(editMenu);
        mainMenu.add(viewMenu);
        mainMenu.add(helpMenu);
        p.add(mainMenu, BorderLayout.NORTH);
}//end calcuteFrame
public static void main(String[] args)
{
      JFrame.setDefaultLookAndFeelDecorated(true);
       CalculateFrame frame = new CalculateFrame();
       frame.setTitle("The Front View of a Microwave Oven");
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 250);
       frame.setVisible(true);
}

public static String operation(String operat,String r,String input)
{
    String result = "";
    if(operat.compareTo("+")==0)
     result = new String(""+(Double.parseDouble(r)+Double.parseDouble(input)));
    else
     if(operat.compareTo("*")==0)
      result = new String(""+(Double.parseDouble(r)*Double.parseDouble(input)));
     else
      if(operat.compareTo("/")==0)
       result = new String(""+(Double.parseDouble(r)/Double.parseDouble(input)));
      else
       if(operat.compareTo("-")==0)
        result = new String(""+(Double.parseDouble(r)-Double.parseDouble(input)));
       /*else
        if(operat.compareTo("%")==0)
         result = new String(""+(Double.parseDouble(r)%Double.parseDouble(input)));
        else
         if(operat.compareTo("sqrt")==0)
          result = new String(""+Math.sqrt(Double.parseDouble(r)));*/
    return result ;
}

class operatorButtonListener implements ActionListener
{
      public void actionPerformed(ActionEvent e)
      {

      }
}
}//end -application