Java程序設計實驗報告-計算器.doc

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1、 Java程序設計實驗報告題 目 計算器 姓 名 學 號 學 院 軟件學院 專 業(yè) 軟件工程 年 級 2009 級 指導教師 2010年 4 月 9 日一、實驗目的1、 熟練掌握java面向對象編程。2、 選擇合適的數(shù)據(jù)結構實現(xiàn)需求。3、 熟練使用各種控制結構。4、 掌握GUI組件、事件處理技術。二、實驗任務1、 設計一個簡易的計算器，可以進行四則運算：加、減、乘、除等（限于十進制下）程序要求：（1）應具有相應的界面，可參考下圖進行設計： 圖示1 圖示2（2）操作符號定為：“+”，“-”，“*”，“/”，“(”,“)”等。（按國際慣例設計）（3）用戶通過點擊面板中的各種組件輸入的表達式，應在上

2、方文本框中顯示。（4）當用戶點擊“=”時，文本框中之前的內容應清空，直接顯示表達式運算結果。例如：輸入表達式“3+2*（8-5）”之后按“=”，顯示結果“9”。（5）具有菜單欄，內有相應的編輯“復制”、“粘貼”等菜單，提供相應的功能。（6）以上部分為必須完成的內容。2、選作功能，可參考windows系統(tǒng)附帶計算器： （1）具有相應的科學計算功能。例如“圖示2”中的各種科學計算功能。三、開發(fā)工具與平臺1.開發(fā)工具：Eclipse默認是一個和Jbuilder類似的Java開發(fā)工具，但它不僅僅只 是Java開發(fā)工具，只要裝上相應的插件，eclipse也可作為其它語言的開發(fā)工具。如C/C+插件(CDT

3、)。2.開發(fā)平臺：JDK1.5四、設計思路1.界面設計 （1）制作一個簡單的面板JFrame，在其上面添加構造界面所需的各種組件其構造方法為：calculate()super();this.setBounds(10, 10, 300, 250);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);this.setResizable(false);this.setTitle(計算器);init();/創(chuàng)建菜單及各種組件（如按鈕，文本框等）getContentPane().setLayout(new BorderLayout(3,3);getCo

4、ntentPane().add(panelCenter,BorderLayout.CENTER);getContentPane().add(panelNorth,BorderLayout.NORTH);（2）實現(xiàn)構造菜單及文本框等組件的函數(shù)init(),如下實現(xiàn)：Public void Init()/菜單項的構造形成； editor.add(copy);editor.addSeparator();editor.add(paste); editor.setMnemonic(E);look.setMnemonic(V);help.setMnemonic(H); copy.setAccelerato

5、r(KeyStroke.getKeyStroke(KeyEvent.VK_C,InputEvent.CTRL_MASK); paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_P,InputEvent.CTRL_MASK); help.add(about); bar.add(editor);bar.add(look);bar.add(help); setJMenuBar(bar);/將菜單添加到JFrame； /* 接下來是文本或結果顯示區(qū)及Backspace、功能鍵（CE、C）和的添加，采用 GridBagLayout布局方式，將它

6、們放在北部panelNorth面板。 其次，是數(shù)字鍵及其他功能鍵的的使用，我這里采用的是網(wǎng)格布局，setLayout(new GridLayout(4,6,5,5);將它們放在主面板中心區(qū)域。 這里給出網(wǎng)格包布布局的兩個重要方法，由于代碼段較長，故將其他的代碼放在后面附錄；private void makeShow(GridBagLayout gridBag,GridBagConstraints constraints, Component component) gridBag.setConstraints(component, constraints);/ 網(wǎng)格包布布局； panelNort

7、h2.add(component);private void addButton(GridBagLayout gridBag,/網(wǎng)格包布布局重要方法；GridBagConstraints constraints, Component component) gridBag.setConstraints(component, constraints); panelNorth1.add(component);總體界面如下：2.邏輯設計 為了能夠得到我們想要的操作，比如讓那些數(shù)字參與運算，做什么運算等等，我們就需要為每個按鈕添加響應事件，通過響應事件來完成我們預期的結果。以下我們來分析下重要的事件是如

8、何響應的：.String str = e.getActionCommand();/ TODO Auto-generated method stubif(str.equals(Backspace)/點擊 BackspacehanderBackspace();else if(str.equals(CE)/點擊了CE的功能是清除當前顯示的數(shù)值bool = false;show.setText(0);else if(str.equals(C)/點擊了C的功能是清零copyText=;Div = 0.0;CalculateResult =;bool = false;show.setText(0);els

9、e if(str.equals(MC)/MC清楚存儲器內容handerMC();else if(str.equals(MR)/MR將存于存儲器的值顯示在文本框中handerMR();else if(str.equals(MS)/MS將顯示框得文字存于存儲器handerMS();else if(str.equals(M+)/M+將顯示框的數(shù)與存儲器中的數(shù)相加并進行存儲handerM();else if(0123456789.indexOf(str)=0)/按下的是數(shù)字鍵或者小數(shù)點正負號handerCenter(str);else if(str.equals(%)/將當前顯示框里的數(shù)字用百分比表示

10、（ x/100）String current = show.getText();double a = 0;if(!current.isEmpty() a = Double.parseDouble(current); Double result =(Double) a/100; String s4 = result.toString(); if(!isInt(s4) show.setText(s4);else show.setText(s4.substring(0,s4.indexOf(.); bool = true; else handerOperation(str);/響應的是運算符；處理運

11、算符操作3. 程序測試 程序測試過程中無較大BUG，基本上輕松搞定。五、實驗總結 這是我第一次正式的java程序設計實驗，感覺能夠把學到的東西用到實際中是件非常有趣的事，更重要的是讓我們真正明白了學貴致用的道理。 由于時間有限，本程序未能做到科學計算器，同時在這里也感謝老師的指導和同學的幫助。6、 附錄public class calculate extends JFrame implements ActionListener /* * param args */private JMenuBar bar = new JMenuBar();private JMenu editor =new JM

12、enu(編輯(E);private JMenuItem copy =new JMenuItem(復制);private JMenuItem paste =new JMenuItem(粘貼);private JMenu look = new JMenu(查看(V);private JMenu help = new JMenu(幫助(H);private JMenuItem about = new JMenuItem(關于);private String copyText ;private JPanel panelWest= new JPanel();private JPanel panelCen

13、ter = new JPanel();/放Number鍵private JPanel panelNorth = new JPanel();/放功能鍵1與文本框private JPanel panelNorth1 = new JPanel();private JPanel panelNorth2 = new JPanel();/放顯示框private JPanel panelEast = new JPanel();/放運算鍵；private String strNorth = new StringBackspace,CE,C;/功能鍵1private String strCenter = new

14、 String7,8,9,4,5,6,1,2,3,0,+/-,.;private String strEast = new String/,sqrt,*,%,-,1/x,+,=;private StringstrWest = new StringMC,MR,MS,M+;private JButton buttonCenter = new JButtonstrCenter.length;private JButton buttonEast= new JButtonstrEast.length;private JButton buttonNorth = new JButtonstrNorth.le

15、ngth;private JButton buttonWest = new JButtonstrWest.length;private String ch=new String();/保存當前運算符private Double Div;/保存中間運算數(shù)private String save = new String();/保存存儲器中的數(shù)值private String CalculateResult= new String() ;/保存運算結果private boolean bool = false;/當前結果是否為運算結果private JTextField show = new JText

16、Field(0,24);/輸出顯示private JTextField label;private GridBagLayout gridBag = new GridBagLayout();/網(wǎng)格包布布局；private GridBagConstraints constraints = new GridBagConstraints();calculate()super();this.setBounds(10, 10, 300, 250);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);this.setResizable(false);thi

17、s.setTitle(計算器);init();getContentPane().setLayout(new BorderLayout(3,3);getContentPane().add(panelCenter,BorderLayout.CENTER);getContentPane().add(panelNorth,BorderLayout.NORTH);public void init() editor.add(copy);editor.addSeparator();editor.add(paste); editor.setMnemonic(E);look.setMnemonic(V);hel

18、p.setMnemonic(H); copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,InputEvent.CTRL_MASK); paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_P,InputEvent.CTRL_MASK); help.add(about); bar.add(editor);bar.add(look);bar.add(help); setJMenuBar(bar); copy.addActionListener(this); paste.addAc

19、tionListener(this); about.addActionListener(this); panelNorth1.setLayout(gridBag);/ panelNorth2.setLayout(gridBag); show.setHorizontalAlignment(JTextField.RIGHT);/右對齊; show.setEditable(false); panelNorth.setLayout(new BorderLayout(); panelNorth.add(show,BorderLayout.NORTH); show.setBorder(new BevelB

20、order(BevelBorder.LOWERED);/讓顯示框凹陷下去 show.setBackground(Color.WHITE); /網(wǎng)格包布布局； constraints.gridx = 0; constraints.gridy = 0; constraints.fill = GridBagConstraints.NONE; constraints.anchor = GridBagConstraints.CENTER; makeShow(gridBag,constraints,show); /* /設置箱式布局間隔 (另一種布局方式) * / box.add(label); for(

21、int i = 0;istrNorth.length;+i) buttonNorthi = new JButton(strNorthi); box.add(Box.createHorizontalStrut(10); box.add(buttonNorthi); buttonNorthi.addActionListener(this); buttonNorthi.setForeground(Color.RED); */ label = new JTextField(2); label.setEditable(false); label.setBorder(new BevelBorder(Bev

22、elBorder.LOWERED);/讓文本框凹陷下去； constraints.gridx = 0; constraints.gridy = 0; constraints.fill = GridBagConstraints.NONE; constraints.insets = new Insets(10,5,10,10); addButton(gridBag,constraints,label); for(int j = 0;jstrNorth.length;+j) buttonNorthj = new JButton(strNorthj); buttonNorthj.addActionLi

23、stener(this); buttonNorthj.setForeground(Color.RED); constraints.gridx =j+1 ; constraints.gridy = 0; addButton(gridBag,constraints,buttonNorthj); panelNorth.add(panelNorth1,BorderLayout.CENTER); panelNorth.add(panelNorth2,BorderLayout.NORTH); panelCenter.setLayout(new GridLayout(4,6,5,5); for(int i

24、=0;istrWest.length;+i) buttonWesti = new JButton(strWesti); buttonWesti.setBorder(new BevelBorder(BevelBorder.RAISED); buttonWesti.setForeground(Color.RED); buttonWesti.addActionListener(this); for(int i =0;istrCenter.length;+i) buttonCenteri = new JButton(strCenteri); buttonCenteri.setBorder(new Be

25、velBorder(BevelBorder.RAISED); buttonCenteri.setForeground(Color.BLUE); buttonCenteri.addActionListener(this); for(int i =0;istrEast.length;+i) buttonEasti = new JButton(strEasti); buttonEasti.setBorder(new BevelBorder(BevelBorder.RAISED); buttonEasti.addActionListener(this); if(i%2=0|(i=7) buttonEa

26、sti.setForeground(Color.RED); else buttonEasti.setForeground(Color.BLUE); int w =0,e = 0, c = 0; for(int i = 0;i24;) if(i%6=0) buttonWestw.setBorder(new LineBorder(Color.GRAY); panelCenter.add(buttonWestw); +i; +w; else for(int j = 0;j3;+j) buttonCenterc.setBorder(new LineBorder(Color.GRAY); panelCe

27、nter.add(buttonCenterc); +i; +c; for(int j = 0;j=0)/按下的是數(shù)字鍵或者小數(shù)點正負號handerCenter(str);else if(str.equals(%)/將當前顯示框里的數(shù)字用百分比表示（ x/100）String current = show.getText();double a = 0;if(!current.isEmpty() a = Double.parseDouble(current); Double result =(Double) a/100; String s4 = result.toString(); if(!isI

28、nt(s4) show.setText(s4);else show.setText(s4.substring(0,s4.indexOf(.); bool = true; else handerOperation(str);private void handerMC() save = ;/ TODO Auto-generated method stublabel.setText();private void handerMR() if(!save.isEmpty() if(!isInt(save) show.setText(save); else show.setText(save.substr

29、ing(0,save.indexOf(.); private void handerMS() save = show.getText();/ TODO Auto-generated method stubprivate void handerM() String str = show.getText();/ TODO Auto-generated method stubdouble s=0,v=0;if(!str.isEmpty()&!save.isEmpty() s= Double.parseDouble(str); v = Double.parseDouble(save);save = S

30、tring.valueOf(s+v);label.setText(M);private void handerCenter(String str) String result = show.getText();if(str.equals(.)if(!(result.indexOf(.)=0)/判斷是否已存在小數(shù)點if(bool)show.setText();result=;result+=str;show.setText(result);bool = false;String num = result;if(*-+/.indexOf(ch)=0) handerResult(ch,num); e

31、lse if(result.equals(0)result=str;show.setText(result);bool = false;String num = result;if(*-+/.indexOf(ch)=0)handerResult(ch,num); else if(bool)show.setText();/文本框不為0.既有數(shù)字或者0和小數(shù)點result = ;result+=str;show.setText(result);bool = false;String num = result;/保存if(*-+/.indexOf(ch)=0) handerResult(ch,num

32、); private void handerOperation(String str) String result = show.getText();if(str.equals(+/-)/處理正負號 if(result.indexOf(-)=0) StringBuffer e = new StringBuffer(result); e.deleteCharAt(0); show.setText(e.toString(); String num = e.toString(); if(*-+/.indexOf(ch)=0) handerResult(ch,num); else StringBuff

33、er e = new StringBuffer(result); e.insert(0, -); show.setText(e.toString(); String num = e.toString(); if(*-+/.indexOf(ch)=0) handerResult(ch,num); else if(str.equals(sqrt)/平方根功能if(!(result.indexOf(-)=0)double operate=0;if(!result.isEmpty() operate =Double.parseDouble(result); double reult = Math.sq

34、rt(operate); Double a = reult; String s =a.toString(); if(!isInt(s) show.setText(s); else show.setText(s.substring(0,s.indexOf(.); bool = true; if(*-+/.indexOf(ch)=0) handerResult(ch,s); else show.setText(函數(shù)輸入無效);bool= true;else if(str.equals(/)/除法運算；String show2 = show.getText();show.setText();ch=/

35、;double operate = 0;if(!show2.isEmpty()operate = Double.parseDouble(show2); Div = (Double)operate;/保存被除數(shù)；else if(str.equals(*)String show2 = show.getText();show.setText();ch=*;/保存當前運算符double operate = 0;if(!show2.isEmpty() operate = Double.parseDouble(show2);Div = (Double)operate;else if(str.equals(

36、-)String show2 = show.getText();show.setText();ch=-;double operate =0;if(!show2.isEmpty() operate= Double.parseDouble(show2);Div = (Double)operate;else if(str.equals(+)String show2 = show.getText();show.setText();ch=+;double operate = 0;if(!show2.isEmpty() operate = Double.parseDouble(show2); Div =

37、(Double)operate;/保存加數(shù)else if(str.equals(1/x)/求倒String show2 = show.getText();if(!show2.equals(0)double operate = 0;if(!show2.isEmpty() operate = Double.parseDouble(show2);double resultReverse = (1/operate);Double resultReverseDouble = resultReverse;show.setText(resultReverseDouble.toString();bool =

38、true;else show.setText(除數(shù)不能為零。);bool = true;else if(str.equals(=)show.setText(CalculateResult);bool = true;private boolean isInt(String s) if(s.indexOf(.)0)for(int i =(s.length()-1);is.indexOf(.);-i) if(!(s.charAt(i)=0) return false;return true;private void handerResult(String ch,String num) /處理運算結果

39、并保存； char swt = 0 ;if(!ch.equals() swt = ch.charAt(0);/將String轉換成charswitch(swt)case -: double resultSub = (Div-Double.parseDouble(num);Double resultSubDouble = resultSub;String s1 = resultSubDouble.toString(); if(!isInt(s1) CalculateResult=s1; else CalculateResult = s1.substring(0,s1.indexOf(.); /保

40、存運算結果；break;case +:double resultAdd = (Div+Double.parseDouble(num);Double resultAddDouble = resultAdd;String s2 = resultAddDouble.toString(); if(!isInt(s2) CalculateResult=s2; else CalculateResult = s2.substring(0,s2.indexOf(.); break;case *: double resultMul = (Div*(Double.parseDouble(num); Double

41、resultMulDouble = resultMul; String s3 = resultMulDouble.toString(); if(!isInt(s3) CalculateResult=s3; else CalculateResult = s3.substring(0,s3.indexOf(.); break;case /: if(Double.parseDouble(num)!=0) double resultDiv = (Div/(Double.parseDouble(num); Double resultDivDouble = resultDiv; String s4 = r

42、esultDivDouble.toString(); if(!isInt(s4) CalculateResult=s4; else CalculateResult = s4.substring(0,s4.indexOf(.); else CalculateResult = 除數(shù)不能為零。; break;private void handerBackspace() /退格鍵String show1 = show.getText();if(!bool)if(!(show1.equals(0)try String result = show1.substring(0, show1.length()-1); show.setText(result); if(result.isEmpty() show.setText(0); return; catch(ArrayIndexOutOfBoundsException e)e.printStackTrace();