用JAVA编写计算器程序

1、用JAVA编写计算器程序（模拟Windows计算器）import java.awt.*;import java.awt.event.*;public class Calculation extends WindowAdapter implements ActionListener double dResult=0; double dNowInput=0; double dMemory; int  n=0; /记载小数位数 int  nOperation=1; / 记录运算符类型 int  nBitsNum

2、=0;  /记录总共输入的位数 boolean alreadyHaveDot=false; /已经有小数点？ boolean keyAvailable=true; boolean alreadyClickedEqueal=false; /是否按下过"="? boolean isTempNowInput=false; /是否在计算出结果后直接按运算符将结果赋给了当前输入值？  Frame f; Panel p1,p2,p3,p4,p5,p6; TextField tf1,tf2;

3、0;Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b0; Button bDiv,bSqrt,bMulti,bMinus,bPercent,bPlus,bReciprocal,bEqual,bDot,bNegative; Button bBackspace,bCE,bC,bMR,bMS,bMC,bM;   public void display()   f=new Frame("计算器");  f.setSize(280,213);  f.setLocation(200,2

4、00);  f.setBackground(Color.LIGHT_GRAY);  f.setResizable(false);    f.setLayout(new BorderLayout(3,3);    p1=new Panel(new GridLayout(1,3,5,5);  /用于存放backspace,ce,c三键  p2=new Panel(new GridLayout(4,5,5,5); /用于存放数字区及附近共20键, 此处间隙设置可能不合理，以后调整  p3=new Panel(n

5、ew GridLayout(5,1,5,5); /用于存放MC,MR,MS,M+键及显示M状态文本框,此处间隙设置可能不合理，以后调整  p4=new Panel(new FlowLayout(); /用于存放p1,p2  p5=new Panel(new FlowLayout();  p6=new Panel(new FlowLayout();  p4.add(p1);  p4.add(p2);    tf1=new TextField(35);      /存放显示区&#

6、160; tf1.setText("0.");  tf1.setEditable(false);  p5.add(tf1);  f.add(p5,BorderLayout.NORTH);  f.add(p4,BorderLayout.CENTER);  f.add(p3,BorderLayout.WEST);    b1=new Button("1");  b2=new Button("2");  b3=new Button("3&qu

7、ot;);  b4=new Button("4");  b5=new Button("5");  b6=new Button("6");  b7=new Button("7");  b8=new Button("8");  b9=new Button("9");  b0=new Button("0");    b1.addActionListener(this);&#

8、160; b2.addActionListener(this);  b3.addActionListener(this);  b4.addActionListener(this);  b5.addActionListener(this);  b6.addActionListener(this);  b7.addActionListener(this);  b8.addActionListener(this);  b9.addActionListener(this);  b0.addActionListener(th

9、is);    bDiv=new Button("/");  bSqrt=new Button("sqrt");  bMulti=new Button("*");  bMinus=new Button("-");  bPercent=new Button("%");  bPlus=new Button("+");  bReciprocal=new Button("1/x");&

10、#160; bEqual=new Button("=");  bDot=new Button(".");  bNegative=new Button("+/-");    bDiv.addActionListener(this);  bSqrt.addActionListener(this);  bMulti.addActionListener(this);  bMinus.addActionListener(this);  bPercent.addAct

11、ionListener(this);  bPlus.addActionListener(this);  bReciprocal.addActionListener(this);  bEqual.addActionListener(this);  bDot.addActionListener(this);  bNegative.addActionListener(this);    p2.add(b7);  p2.add(b8);  p2.add(b9);  p2.add(bDiv); 

12、 p2.add(bSqrt);  p2.add(b4);  p2.add(b5);  p2.add(b6);  p2.add(bMulti);  p2.add(bPercent);  p2.add(b1);  p2.add(b2);  p2.add(b3);  p2.add(bMinus);  p2.add(bReciprocal);  p2.add(b0);  p2.add(bNegative);  p2.add(bDot);  p2.add(bPlus

13、);  p2.add(bEqual);    bBackspace=new Button("Backspace");  bCE=new Button("CE");  bC=new Button("C");    bBackspace.addActionListener(this);  bCE.addActionListener(this);  bC.addActionListener(this);    p1.add(bBac

14、kspace);   p1.add(bCE);  p1.add(bC);    tf2=new TextField(2);  tf2.setEnabled(false);  tf2.setBackground(Color.LIGHT_GRAY);  bMC=new Button("MC");  bMR=new Button("MR");  bMS=new Button("MS");  bM=new Button("M+&quo

15、t;);    bMC.addActionListener(this);  bMR.addActionListener(this);  bMS.addActionListener(this);  bM.addActionListener(this);    p6.add(tf2);  p3.add(p6);  p3.add(bMC);  p3.add(bMR);  p3.add(bMS);  p3.add(bM);    f.setVisible(true

16、);  f.addWindowListener(this);    public void actionPerformed(ActionEvent e)    /key 0 to 9  if(this.keyAvailable && e.getActionCommand().length()=1 && e.getActionCommand().compareTo("0")>=0 && e.getActionCommand().compareTo(&qu

17、ot;9")<=0)     if(this.isTempNowInput)       this.dNowInput=0;    this.isTempNowInput=false;      this.nBitsNum+;    if(this.alreadyHaveDot=false)    this.dNowInput=this.dNowInput*10+Doub

18、le.parseDouble(e.getActionCommand();   else       double temp=Double.parseDouble(e.getActionCommand();    for(int i=this.n;i<0;i+)              temp*=0.1;       

19、this.dNowInput+=temp;    this.n-;      this.tf1.setText(Double.toString(this.dNowInput);    / key dot  if(this.keyAvailable && e.getActionCommand()=".")     if(this.alreadyHaveDot=false)       

20、;this.nBitsNum+;    this.alreadyHaveDot=true;    this.n=-1;        /key "+","-","*","/"  if(this.keyAvailable && e.getActionCommand()="+" | e.getActionCommand()="-" | e.getActio

21、nCommand()="*" | e.getActionCommand()="/")     if(this.alreadyClickedEqueal)       this.dNowInput=this.dResult;    this.isTempNowInput=true;      else       switch(this.nOperation)

22、         case 1: this.dResult+=this.dNowInput; break;     case 2: this.dResult-=this.dNowInput; break;     case 3: this.dResult*=this.dNowInput; break;     case 4:        

23、;   if(this.dNowInput=0)             tf1.setText("除数不能为零");       this.keyAvailable=false;            else this.dResult=this.dResult/this.dNowInp

24、ut;             if(this.keyAvailable)tf1.setText(Double.toString(this.dResult);    this.dNowInput=0;          if(e.getActionCommand()="+")       this.nOperation=1;  

25、     if(e.getActionCommand()="-")       this.nOperation=2;      if(e.getActionCommand()="*")       this.nOperation=3;      if(e.getActionCommand()="/")   &

26、#160;   this.nOperation=4;      this.nBitsNum=0;   this.alreadyClickedEqueal=false;    / key "+/-"   if(this.keyAvailable && e.getActionCommand()="+/-")     this.dNowInput=0-this.dNowInput;  

27、tf1.setText(Double.toString(this.dNowInput);       / key "C"   if(e.getActionCommand()="C")     this.nBitsNum=0;   this.dResult=0;   this.dNowInput=0;   this.alreadyHaveDot=false;   this.n=0; 

28、60; this.nOperation=1;   this.keyAvailable=true;   this.alreadyClickedEqueal=false;   tf1.setText("0.");    / key "CE"  if(e.getActionCommand()="CE")     this.nBitsNum=0;   this.dNowInput=0; 

29、0; this.alreadyHaveDot=false;   this.n=0;   this.nOperation=1;   this.keyAvailable=true;   tf1.setText("0.");      / key "sqrt"  if(this.keyAvailable && e.getActionCommand()="sqrt")     i

30、f(this.alreadyClickedEqueal)       if(this.dResult>=0)         this.dResult=Math.sqrt(this.dResult);     tf1.setText(Double.toString(this.dResult);        else     

31、60;   tf1.setText("函数输入无效");     this.keyAvailable=false;          else       if(this.dNowInput>=0)         this.dNowInput=Math.sqrt(this.dNowInput);  &

32、#160;  tf1.setText(Double.toString(this.dNowInput);        else         tf1.setText("函数输入无效");     this.keyAvailable=false;           / key "1/x"  if(

33、this.keyAvailable && e.getActionCommand()="1/x")     if(this.dNowInput=0)       tf1.setText("除数不能为零");    this.keyAvailable=false;      else       this.dNowInput=1/this.dNo

34、wInput;    tf1.setText(Double.toString(this.dNowInput);       / key "="  if(this.keyAvailable && e.getActionCommand()="=")     this.alreadyClickedEqueal=true;   switch(this.nOperation)    

35、0;  case 1: this.dResult+=this.dNowInput; break;    case 2: this.dResult-=this.dNowInput; break;    case 3: this.dResult*=this.dNowInput; break;    case 4:         if(this.dNowInput=0)      

36、     tf1.setText("除数不能为零");      this.keyAvailable=false;          else this.dResult=this.dResult/this.dNowInput;          if(this.keyAvailable)tf1.setText(Double.toStrin

37、g(this.dResult);      / key "MS"  if(this.keyAvailable && e.getActionCommand()="MS")     this.dMemory=this.dNowInput;   if(this.dMemory!=0)    tf2.setText("M");    / key "MC"  i

38、f(this.keyAvailable && e.getActionCommand()="MC")     this.dMemory=0;   tf2.setText("");    / key "MR"  if(this.keyAvailable && e.getActionCommand()="MR")     this.dNowInput=this.dMemory;&#

39、160;  tf1.setText(Double.toString(this.dNowInput);    / key "M+"  if(this.keyAvailable && e.getActionCommand()="M+")     this.dMemory+=this.dNowInput;   if(this.dMemory!=0)    tf2.setText("M"); 

40、60; else tf2.setText("");    / key "%"  if(this.keyAvailable && e.getActionCommand()="%")     this.dNowInput=(this.dResult*this.dNowInput)/100;   tf1.setText(Double.toString(this.dNowInput);    / key "Backspace"  if(this.keyAvailable && e.getActionCommand()="Backspace")     if(!this.alreadyClickedEqueal)    if(this.dNowInput!=0)         if(this.alreadyHaveDot)