java編寫的簡(jiǎn)單的計(jì)算器程序Word版

1、計(jì)算器項(xiàng)目?jī)?nèi)容：編寫一個(gè)Applet，模仿windows附件所帶計(jì)算器的功能，可以幫助用戶完成計(jì)算功能，具體如下圖所示。項(xiàng)目要求：使用圖形的方式借助窗口、菜單、按鈕等標(biāo)準(zhǔn)界面元素和鼠標(biāo)操作，來幫助用戶方便地向計(jì)算機(jī)系統(tǒng)發(fā)出命令，啟動(dòng)操作，并將系統(tǒng)運(yùn)行的結(jié)果同樣以圖形的方式顯示給用戶，這樣更加直觀和生動(dòng)； 1. Applet容器中組件的添加與設(shè)置，包括面板以及菜單的使用； 2. 容器中組件的布局管理； 3. Java核心包中數(shù)組、數(shù)學(xué)計(jì)算類的使用； 4. 異常的處理； 5. 事件處理模型中的三類對(duì)象的使用： 1. Event-事件，用戶對(duì)界面操作在java語言上的描述，以類的形式出現(xiàn)，例如鍵盤操

2、作對(duì)應(yīng)的事件類是KeyEvent。 2. Event Source-事件源，事件發(fā)生的場(chǎng)所，通常就是各個(gè)組件，例如按鈕Button。 3. Event handler-事件處理者，接收事件對(duì)象并對(duì)其進(jìn)行處理的對(duì)象。 6. 程序中事件處理的流程：1. 計(jì)算流程的細(xì)化 參考代碼：import java.awt.*;import java.lang.*;import javax.swing.*;import javax.swing.event.*;import java.awt.event.*;import java.text.DecimalFormat;public class Calculato

3、r    implements ActionListener /導(dǎo)入動(dòng)作監(jiān)聽接口  /設(shè)計(jì)面板中的單位  JFrame frame;  JTextField textAnswer;  JPanel panel, panel1, panel2, panel3;  JMenuBar mainMenu;  JTextField textMemory;  JLabel labelMemSpace; /labelMemSpace單純做擺設(shè)，控制面板的形狀  JButton buttonBk, b

4、uttonCe, buttonC;  JButton button;  JButton buttonMC, buttonMR, buttonMS, buttonMAdd;  JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul,      buttonDiv, buttonMod;  JButton buttonSqrt, buttonDao, buttonEqual;  JMenu editMenu, viewM

5、enu, helpMenu;  JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, topHelp, aboutCal;  DecimalFormat df; /設(shè)置數(shù)據(jù)輸出精度  boolean clickable; /控制當(dāng)前能否按鍵  double memoryd; /使用內(nèi)存中存儲(chǔ)的數(shù)字  int memoryi;  double vard, answerd; /用來保存double型數(shù)據(jù)的中間值(vard)和最后結(jié)果(answerd)  short k

6、ey = -1, prekey = -1; /key用來保存當(dāng)前進(jìn)行何種運(yùn)算,prekey用來保存前次進(jìn)行何種運(yùn)算  String copy; /做復(fù)制用  JTextArea help; /幫助  JScrollPane scrollHelp;  /構(gòu)造函數(shù)  public Calculator()     clickable = true;    answerd = 0;    frame = new JFrame("計(jì)算器");&

7、#160;   df = new DecimalFormat("0.#"); /設(shè)置數(shù)據(jù)輸出精度(對(duì)于double型值)    textAnswer = new JTextField(15);    textAnswer.setText("");    textAnswer.setEditable(false);    textAnswer.setBackground(new Color(255, 255, 255)

8、;    panel = new JPanel();    frame.getContentPane().add(panel);    panel1 = new JPanel();    panel2 = new JPanel();    panel.setLayout(new BorderLayout();    /設(shè)計(jì)整個(gè)面板    mainMenu = new JMenuBar()

9、;    editMenu = new JMenu("編輯(E)");    viewMenu = new JMenu("查看(V)");    helpMenu = new JMenu("幫助(H)");    copyItem = new JMenuItem("   復(fù)制(C) Ctrl+C");    copyItem.addActionLi

10、stener(this);    pasteItem = new JMenuItem("   粘貼(V) Ctrl+V");    pasteItem.addActionListener(this);    editMenu.add(copyItem);    editMenu.add(pasteItem);    tItem = new JMenuItem("標(biāo)準(zhǔn)型(T)");

11、0;   tItem.addActionListener(this);    sItem = new JMenuItem("   科學(xué)型(S)");    sItem.addActionListener(this);    numberGroup = new JMenuItem("   數(shù)字分組(I)");    numberGroup.addActionListener(th

12、is);    viewMenu.add(tItem);    viewMenu.add(sItem);    viewMenu.add(numberGroup);    topHelp = new JMenuItem("   幫助主題(H)");    topHelp.addActionListener(this);    help = new JTextArea(5, 20

13、);    scrollHelp = new JScrollPane(help);    help.setEditable(false);    help.append("執(zhí)行簡(jiǎn)單計(jì)算n");    help.append("1.  鍵入計(jì)算的第一個(gè)數(shù)字。n");    help.append("2.  單擊“+”執(zhí)行加、“-”執(zhí)行減、“*”執(zhí)行乘或“/”執(zhí)行除。n"

14、);    help.append("3.  鍵入計(jì)算的下一個(gè)數(shù)字。n");    help.append("4.  輸入所有剩余的運(yùn)算符和數(shù)字。n");    help.append("5.  單擊“=”。n");    aboutCal = new JMenuItem("   關(guān)于計(jì)算器(A)");    abou

15、tCal.addActionListener(this);    helpMenu.add(topHelp);    helpMenu.add(aboutCal);    mainMenu.add(editMenu);    mainMenu.add(viewMenu);    mainMenu.add(helpMenu);    panel.add(mainMenu, BorderLayout.NORTH);

16、60;   panel.add(textAnswer, BorderLayout.CENTER);    panel.add(panel1, BorderLayout.SOUTH);    panel1.setLayout(new BorderLayout();    textMemory = new JTextField(3);    textMemory.setEditable(false);    textMemory.

17、setBackground(new Color(217, 217, 217);    labelMemSpace = new JLabel("                   ");    buttonBk = new JButton("Backspace");    buttonBk

18、.setForeground(new Color(255, 0, 0);    buttonCe = new JButton("CE");    buttonCe.setForeground(new Color(255, 0, 0);    buttonC = new JButton("C");    buttonC.setForeground(new Color(255, 0, 0);    button

19、Bk.addActionListener(this);    buttonCe.addActionListener(this);    buttonC.addActionListener(this);    panel1.add(panel2, BorderLayout.NORTH);    panel2.setLayout(new FlowLayout(FlowLayout.RIGHT);    panel2.add(textMemory);&

20、#160;   panel2.add(labelMemSpace);    panel2.add(buttonBk);    panel2.add(buttonCe);    panel2.add(buttonC);    panel3 = new JPanel();    panel1.add(panel3, BorderLayout.CENTER);    button = new JButt

21、on10;    for (int i = 0; i < button.length; i+)       buttoni = new JButton(Integer.toString(i);      buttoni.setForeground(new Color(0, 0, 255);        buttonMC = new JButton("MC"); 

22、0;  buttonMC.setForeground(new Color(255, 0, 0);    buttonMR = new JButton("MR");    buttonMR.setForeground(new Color(255, 0, 0);    buttonMS = new JButton("MS");    buttonMS.setForeground(new Color(255, 0, 0); 

23、;   buttonMAdd = new JButton("M+");    buttonMAdd.setForeground(new Color(255, 0, 0);    buttonDot = new JButton(".");    buttonDot.setForeground(new Color(0, 0, 255);    buttonAddAndSub = new JButton("+/-

24、");    buttonAddAndSub.setForeground(new Color(0, 0, 255);    buttonAdd = new JButton("+");    buttonAdd.setForeground(new Color(255, 0, 0);    buttonSub = new JButton("-");    buttonSub.setForeground

25、(new Color(255, 0, 0);    buttonMul = new JButton("*");    buttonMul.setForeground(new Color(255, 0, 0);    buttonDiv = new JButton("/");    buttonDiv.setForeground(new Color(255, 0, 0);    buttonMod = new

26、 JButton("%");    buttonMod.setForeground(new Color(0, 0, 255);    buttonSqrt = new JButton("sqrt");    buttonSqrt.setForeground(new Color(0, 0, 255);    buttonDao = new JButton("1/x");    button

27、Dao.setForeground(new Color(0, 0, 255);    buttonEqual = new JButton("=");    buttonEqual.setForeground(new Color(255, 0, 0);    /將所有行為與監(jiān)聽綁定    panel3.setLayout(new GridLayout(4, 6);    panel3.add(buttonMC); &#

28、160;  buttonMC.addActionListener(this);    panel3.add(button7);    button7.addActionListener(this);    panel3.add(button8);    button8.addActionListener(this);    panel3.add(button9);    button9.addActionL

29、istener(this);    panel3.add(buttonDiv);    buttonDiv.addActionListener(this);    panel3.add(buttonSqrt);    buttonSqrt.addActionListener(this);    panel3.add(buttonMR);    buttonMR.addActionListener(this);

30、0;   panel3.add(button4);    button4.addActionListener(this);    panel3.add(button5);    button5.addActionListener(this);    panel3.add(button6);    button6.addActionListener(this);    panel3.add(butt

31、onMul);    buttonMul.addActionListener(this);    panel3.add(buttonMod);    buttonMod.addActionListener(this);    panel3.add(buttonMS);    buttonMS.addActionListener(this);    panel3.add(button1);  

32、60; button1.addActionListener(this);    panel3.add(button2);    button2.addActionListener(this);    panel3.add(button3);    button3.addActionListener(this);    panel3.add(buttonSub);    buttonSub.addActionListe

33、ner(this);    panel3.add(buttonDao);    buttonDao.addActionListener(this);    panel3.add(buttonMAdd);    buttonMAdd.addActionListener(this);    panel3.add(button0);    button0.addActionListener(this); 

34、0;  panel3.add(buttonAddAndSub);    buttonAddAndSub.addActionListener(this);    panel3.add(buttonDot);    buttonDot.addActionListener(this);    panel3.add(buttonAdd);    buttonAdd.addActionListener(this);  

35、0; panel3.add(buttonEqual);    buttonEqual.addActionListener(this);    frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);    frame.pack();    frame.show();    /設(shè)置各個(gè)按鈕行為  public void actionPerformed(ActionEvent event)  

36、   boolean sign = false; /判斷是否是double型數(shù)參與運(yùn)算，是為true，不是為false    Object temp = event.getSource();    try       /如果按下數(shù)據(jù)按鈕，將按下的按鈕代表的數(shù)據(jù)插入的當(dāng)前文本框字符串之后      for (int i = 0; i <= 9; i+)     &

37、#160;  if (temp = buttoni && clickable = true)          textAnswer.setText(textAnswer.getText() + Integer.toString(i);          /按下'.'按鈕時(shí)，判斷當(dāng)前文本框內(nèi)字符串中含不含'.'，如果已含，則不允許再插入'.'&

38、#160;     if (temp = buttonDot && clickable = true)         boolean isDot = false;        if (textAnswer.getText().length() = 0)          isDot = true; 

39、       for (int i = 0; i < textAnswer.getText().length(); i+)          if ('.' = textAnswer.getText().charAt(i)             isDot = true;   

40、0;        break;                  if (isDot = false)          textAnswer.setText(textAnswer.getText() + ".");   

41、60;        if ( (temp = buttonAdd | temp = buttonSub | temp = buttonMul |            temp = buttonDiv) && clickable = true)         /'+'操作    &#

42、160;   if (temp = buttonAdd)           switch (prekey)             case 0:              answerd += Double.parseDouble(textAns

43、wer.getText();              break;            case 1:              answerd -= Double.parseDouble(textAnswer.getText

44、();              break;            case 2:              answerd *= Double.parseDouble(textAnswer.getText(); &#

45、160;            break;            case 3:              if (Double.parseDouble(textAnswer.getText() = 0)    

46、60;            textAnswer.setText("除數(shù)不能為零");                clickable = false;             

47、60;             else                answerd /= Double.parseDouble(textAnswer.getText();             

48、 break;            default:              answerd = Double.parseDouble(textAnswer.getText();               

49、0;    textAnswer.setText("");          prekey = key = 0;                /'-'操作        if (temp = buttonSub)  

50、60;        switch (prekey)             case 0:              answerd += Double.parseDouble(textAnswer.getText();     

51、0;        break;            case 1:              answerd -= Double.parseDouble(textAnswer.getText();       

52、60;      break;            case 2:              answerd *= Double.parseDouble(textAnswer.getText();         &#

53、160;    break;            case 3:              if (Double.parseDouble(textAnswer.getText() = 0)            

54、60;    textAnswer.setText("除數(shù)不能為零");                clickable = false;                      

55、60;     else                answerd /= Double.parseDouble(textAnswer.getText();              break;       

56、;     default:              answerd = Double.parseDouble(textAnswer.getText();                    textAnswer.setText("&q

57、uot;);          prekey = key = 1;                /'*'操作        if (temp = buttonMul)           sw

58、itch (prekey)             case 0:              answerd += Double.parseDouble(textAnswer.getText();              bre

59、ak;            case 1:              answerd -= Double.parseDouble(textAnswer.getText();              break; &#

60、160;          case 2:              answerd *= Double.parseDouble(textAnswer.getText();              break;   &

61、#160;        case 3:              if (Double.parseDouble(textAnswer.getText() = 0)                 textAnswer.setText("除

62、數(shù)不能為零");                clickable = false;                            else  

63、0;             answerd /= Double.parseDouble(textAnswer.getText();              break;            default:  &#

64、160;           answerd = Double.parseDouble(textAnswer.getText();                    textAnswer.setText("");       

65、   prekey = key = 2;                /'/'操作        if (temp = buttonDiv)           switch (prekey)      

66、0;      case 0:              answerd += Double.parseDouble(textAnswer.getText();              break;       

67、60;    case 1:              answerd -= Double.parseDouble(textAnswer.getText();              break;         &#

68、160;  case 2:              answerd *= Double.parseDouble(textAnswer.getText();              break;           

69、case 3:              if (Double.parseDouble(textAnswer.getText() = 0)                 textAnswer.setText("除數(shù)不能為零");      

70、;          clickable = false;                            else          

71、0;     answerd /= Double.parseDouble(textAnswer.getText();              break;            default:          &#

72、160;   answerd = Double.parseDouble(textAnswer.getText();                    textAnswer.setText("");          prekey = key = 3;   

73、                 /'='操作      if (temp = buttonEqual && clickable = true)         /如果連續(xù)按'=',則進(jìn)行連續(xù)運(yùn)算        if (p

74、rekey = 5)           if (key = 0)             answerd += vard;            textAnswer.setText(df.format(answerd);     

75、60;              if (key = 1)             answerd -= vard;            textAnswer.setText(df.format(answerd);   

76、0;                if (key = 2)             answerd *= vard;            textAnswer.setText(df.format(answerd);  

77、;                  if (key = 3)             if (Double.parseDouble(textAnswer.getText() = 0)             

78、  textAnswer.setText("除數(shù)不能為零");              clickable = false;                        else    

79、           answerd /= vard;              textAnswer.setText(df.format(answerd);                  

80、60;                   else           vard = Double.parseDouble(textAnswer.getText();          if (key = 0)     

81、;        prekey = -1;            answerd += Double.parseDouble(textAnswer.getText();            textAnswer.setText(df.format(answerd);   

82、60;                if (key = 1)             prekey = -1;            answerd -= Double.parseDouble(textAnswer.getText();&

83、#160;           textAnswer.setText(df.format(answerd);                    if (key = 2)             prekey

84、 = -1;            answerd *= Double.parseDouble(textAnswer.getText();            textAnswer.setText(df.format(answerd);            

85、0;       if (key = 3)             prekey = -1;            if (Double.parseDouble(textAnswer.getText() = 0)          

86、;     textAnswer.setText("除數(shù)不能為零");              clickable = false;                        else

87、               answerd /= Double.parseDouble(textAnswer.getText();              textAnswer.setText(df.format(answerd);        

88、0;                             prekey = 5;            /'%'操作，對(duì)第二個(gè)操作數(shù)除以100      if (temp = bu

89、ttonMod && clickable = true)         if (answerd = 0)           String s = textAnswer.getText();          textAnswer.setText(s);      

90、60;         else           boolean isDot = false;          for (int i = 0; i < textAnswer.getText().length(); i+)          

91、;  if ('.' = textAnswer.getText().charAt(i)               isDot = true;              break;           

92、           /如果是double數(shù)，除100          if (isDot = true)             double dtemp = Double.parseDouble(textAnswer.getText();     

93、60;      dtemp = dtemp / 100.0;            textAnswer.setText(Double.toString(dtemp);                    else    &#

94、160;        /如果是int數(shù)但能被100整除，則去掉末尾兩個(gè)零            if (Integer.parseInt(textAnswer.getText() % 100 = 0)               int itemp = Integer.parseInt(

95、textAnswer.getText();              itemp /= 100;              textAnswer.setText(Integer.toString(itemp);           

96、;             /如果是int數(shù)，但不能被100整除，則按double數(shù)處理            else               double dtemp = Double.parseDouble(textAnswer.getTe

97、xt();              dtemp = dtemp / 100.0;              textAnswer.setText(Double.toString(dtemp);             

98、                             /開根號(hào)運(yùn)算      if (temp = buttonSqrt && clickable = true)         String s = text

99、Answer.getText();        if (s.charAt(0) = '-')           textAnswer.setText("負(fù)數(shù)不能開根號(hào)");          clickable = false;       

100、;         else          textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.              parseDouble(textAnswer.getText();   

101、0;        /倒數(shù)運(yùn)算      if (temp = buttonDao && clickable = true)         if (textAnswer.getText().charAt(0) = '0' &&            textA

102、nswer.getText().length() = 1)           textAnswer.setText("零不能求倒數(shù)");          clickable = false;                else   

103、        boolean isDec = true;          int i, j, k;          String s = Double.toString(1 / Double.parseDouble(textAnswer.getText();       &

104、#160;  for (i = 0; i < s.length(); i+)            if (s.charAt(i) = '.')              break;          for (j = i + 1; j

105、 < s.length(); j+)            if (s.charAt(j) != '0')               isDec = false;              break;&#

106、160;                     if (isDec = true)             String stemp = ""            f

107、or (k = 0; k < i; k+)              stemp += s.charAt(k);            textAnswer.setText(stemp);              

108、0;     else            textAnswer.setText(s);                    /按下'+/-'按鈕時(shí)處理      if (temp = buttonAddAnd

109、Sub && clickable = true)         boolean isNumber = true;        String s = textAnswer.getText();        for (int i = 0; i < s.length(); i+)       &#

110、160;  if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' | s.charAt(i) = '.' |                 s.charAt(i) = '-')          

111、0;  isNumber = false;            break;                  if (isNumber = true)           /如果當(dāng)前字符串首字母有'-'號(hào),代表

112、現(xiàn)在是個(gè)負(fù)數(shù),再按下時(shí),則將首符號(hào)去掉          if (s.charAt(0) = '-')             textAnswer.setText("");            for (int i = 1; i < s.len

113、gth(); i+)               char a = s.charAt(i);              textAnswer.setText(textAnswer.getText() + a);           

114、;                     /如果當(dāng)前字符串第一個(gè)字符不是符號(hào)，則添加一個(gè)符號(hào)在首字母處          else            textAnswer.setText('-' +

115、 s);                    /計(jì)算器有關(guān)內(nèi)存操作      /'MC'的操作，將內(nèi)存清0      if (temp = buttonMC && clickable = true)         memor

116、yd = memoryi = 0;        textMemory.setText("");            /'MS'的操作，將當(dāng)前文本框內(nèi)容保存入內(nèi)存，顯示'M'      if (temp = buttonMS && clickable = true)         boolean isDot = false;        textMemory.setText("   M");        for (int i = 0; i < textAnswer.getText().length(); i+)