JAVA小计算器[浩特个人网]

今天是：	本站首页文章频道动画频道下载频道图片频道在线书库魔方世界英语广播音乐在线笨笨论坛

·设为首页

·在线留言

·关于本站

您现在的位置：浩特个人网 >> 文章频道 >> 编程源码 >> JAVA源代码 >> 正文

本站公告：

JAVA小计算器

热

JAVA小计算器

［作者：无来源：搜集整理点击数：更新时间：2006-05-30 文章录入：无］

【字体：

】

不才，小弟学一个月JAVA写的一个老师作业，JAVA小计算器，还很薄弱，难以抗拒"不法用户"的使用，先传上来供大虾们笑笑！

//Calculater（程序员是像写情书一样写代码)
import java.awt.*;
import java.awt.event.*;

class MainPanel extends Panel //Screen Panle class
{
   TextField scn=new TextField(""); //TextField screen
   String str[]={"7","8","9","*","4","5","6","-","1","2","3","+","0",".","/","="};
   Button btn[]=new Button[str.length];
   String temp,op,tempInKey,keyDown;
   char opChar;
   public float num1,num2;
   boolean flag;

   MainPanel()
   {
       Panel ScreenPanel = new Panel(); //Screen Panel
       //scn; //Welcome to Calculater!
       ScreenPanel.setLayout(new BorderLayout());//Screen in the north
       ScreenPanel.add(scn,BorderLayout.CENTER);
       scn.disable(); //can not receive event
       keyInput kPut=new keyInput(); //keyAction
       scn.addKeyListener(kPut);

       Panel ButtonPanel = new Panel();   //Button Panel
       ButtonPanel.setLayout(new GridLayout(4,4));
       for (int i=0;i<16;i++)
       {
           btn[i]=new Button(str[i]); //new Button
           ButtonPanel.add(btn[i]); //add to panel
           btn[i].addActionListener(new lsn());
           btn[i].addKeyListener(kPut); //buttons be listened
       }

       //scn.addKeyListener(kPut);

       //Add to Main Panel

       setLayout(new BorderLayout()); //Main panel
       add(ScreenPanel,BorderLayout.NORTH);
       add(ButtonPanel,BorderLayout.CENTER);
   }

   class lsn implements ActionListener //listener
   {
       public void actionPerformed(ActionEvent e)
       {
           temp=scn.getText();   //save the numbers on screen first
           //judge
           if (flag)
               {
                   temp= "";    //clear the numbers on the screen
                   flag=false;
               }
           if (e.getActionCommand()=="+" |e.getActionCommand()=="-"
                   |e.getActionCommand()=="*" |e.getActionCommand()=="/")
               {                     //if operation clicked
                       if (scn.getText().equals("") ) //等于时没有内容的处理
                          return;

                       num1=Float.parseFloat(scn.getText());
                       op=e.getActionCommand(); //operation type
                       scn.setText("");
               }
           else if (e.getActionCommand()=="=") //calculate
               {
               try{
                      if (scn.getText().equals("") ) //等于时没有内容的处理
                          return;

                        num2=Float.parseFloat(scn.getText());
                       if (op=="+")
                           num2=num1+num2;
                       else if (op=="-")
                           num2=num1-num2;
                       else if (op=="*")
                           num2=num1*num2;

                       else if   (op=="/")
                       {
                           //if(num2 < 0.0000001 & num2>0.00000001)
                           //{
                           //   scn.setText("0不能做除数");
                           //   flag=true;
                       //       return;
                       //   }
                           num2=num1/num2;
                       }
                       scn.setText(String.valueOf(num2));
                       flag=true;
                   }
                   catch(ArithmeticException ex)
                   {
                        System.out.println(ex.toString());
                   }
               }
           //else if (e.getActionCommand()=="CLS") //clear
           //   scn.setText("");
           else   //add to screen
               scn.setText(temp+e.getActionCommand()); //setText
       }
   }

   class keyInput extends KeyAdapter
   {
       public void keyPressed (KeyEvent k)
       {
           if ((k.getKeyCode()>47 & k.getKeyCode()<58) | (k.getKeyCode()>96 & k.getKeyCode()<112)
                       |k.getKeyCode()==10)
           {
               tempInKey=scn.getText(); //num1
               keyDown=String.valueOf(k.getKeyChar()); //char to String
               System.out.print(k.getKeyChar());
               if (flag)
                   {
                       tempInKey= "";    //clear the numbers on the screen
                       flag=false;
                   }
               if (k.getKeyChar()=='+'|k.getKeyChar()=='-'|k.getKeyChar()=='*'|
                       k.getKeyChar()=='/')
                   {
                       if (scn.getText().equals("") ) //等于时没有内容的处理
                              return;
                      num1=Float.parseFloat(scn.getText());
                       opChar=k.getKeyChar();
                       scn.setText("");
                   }
               else if (k.getKeyChar()=='='|k.getKeyCode()==10) //calculate
               {
               try{
                  System.out.println(opChar);
                      if (scn.getText().equals("") ) //等于时没有内容的处理
                          return;
                        num2=Float.parseFloat(scn.getText());
                       if (opChar=='+')
                           num2=num1+num2;
                       else if (opChar=='-')
                           num2=num1-num2;
                       else if (opChar=='*')
                           num2=num1*num2;

                       else if   (opChar=='/')
                       {
                           //if(num2 < 0.0000001 & num2>0.00000001)
                           //{
                           //   scn.setText("0不能做除数");
                           // flag=true;
                           //   return;
                           //}
                           num2=num1/num2;
                       }
                       scn.setText(String.valueOf(num2));
                       flag=true;
                   }
                   catch(ArithmeticException ex)
                   {
                       System.out.println(ex.toString());
                   }
               }
               else
                   scn.setText(tempInKey+keyDown); //set
           }
           else
               return;
       }
   }
}

class CalcFrame extends Frame   //construct a frame
{
   public CalcFrame(String title)
   {
       super(title);
       MainPanel pScr=new MainPanel(); //Main Panel
       add(pScr);   //add MainFrame
       addWindowListener(new end()); //add listener
   }

   class end extends WindowAdapter //close the window,inner class
   {
       public void windowClosing(WindowEvent e)
       {
           System.exit(0);
       }
   }
}

class Calculater //main()
{
   public static void main(String args[])
   {
       CalcFrame frm=new CalcFrame("JAVA计算器");
       frm.setSize(220,180); //new frame,go above
       frm.show();
   }
}

上一篇文章： JAVA程序__计算器

下一篇文章： java编写TCP方式的通信程序