JAVA小應(yīng)用程序Applet設(shè)計(jì)計(jì)算器實(shí)驗(yàn)報(bào)告附完整代碼

1、小應(yīng)用程序Applet設(shè)計(jì)一、 課題內(nèi)容和要求內(nèi)容：設(shè)計(jì)和編寫一個可以用鼠標(biāo)操作的Applet小應(yīng)用程序和相應(yīng)的HTML頁面，觀察Applet的執(zhí)行過程，測試程序鼠標(biāo)用戶交互操作的效果。要求：要求學(xué)生能在學(xué)習(xí)和理解課堂學(xué)習(xí)內(nèi)容中JAVA小應(yīng)用程序的基礎(chǔ)上，通過實(shí)驗(yàn)，培養(yǎng)學(xué)生將JAVA小應(yīng)用程序相關(guān)知識點(diǎn)（包括JAVA Applet和低級事件處理模型）有機(jī)結(jié)合，設(shè)計(jì)基于WEB瀏覽器的小應(yīng)用程序的能力。二、設(shè)計(jì)思路分析class App:一個Java Applet計(jì)算器的主類public void init():完成初始化appletpublic boolean action():實(shí)現(xiàn)事件處理的方

2、法public void doOperator():運(yùn)算及運(yùn)算結(jié)果輸出操作public void doForeScreen():數(shù)字和小數(shù)點(diǎn)輸出到文本框操作public void doClear():清空操作三、概要設(shè)計(jì) public class App extends Applet TextField tfAnswer;Button b0, b1, b2, b3, b4, b5, b6, b7, b8, b9;Button bPoint, bEqual, bPlus, bMinus, bClear, bMulti, bDivision;String OperatorCurrent, Oper

3、atorPre;String ForeScreen, BackScreen;boolean isFloat = false;public void init();public boolean action(Event e, Object o);public void doOperator()public void doForeScreen(String s);public void doClear();事件處理:運(yùn)算及運(yùn)算結(jié)果輸出:四、詳細(xì)設(shè)計(jì) Java代碼：import java.awt.*;import java.applet.*;public class App extends Appl

4、et TextField tfAnswer;/ 定義變量Button b0, b1, b2, b3, b4, b5, b6, b7, b8, b9;Button bPoint, bEqual, bPlus, bMinus, bClear, bMulti, bDivision;String OperatorCurrent, OperatorPre;String ForeScreen, BackScreen;boolean isFloat = false;public void init() / 初始化OperatorCurrent = new String();OperatorPre = new

5、 String();ForeScreen = new String(0);/ 保證輸入字符串不為空防止計(jì)算錯誤BackScreen = new String();setBackground(Color.gray);setLayout(null);/ 設(shè)為空布局便于自定義組件位置tfAnswer = new TextField();/ 設(shè)置文本框樣式tfAnswer.setBounds(20, 20, 175, 40);tfAnswer.setFont(new Font(BackScreen, Font.BOLD, 28);add(tfAnswer);tfAnswer.setText(ForeS

6、creen);bClear = new Button(C);/ 設(shè)置按鈕樣式bClear.setBounds(20, 70, 40, 40);add(bClear);bDivision = new Button(/);bDivision.setBackground(Color.green);bDivision.setBounds(65, 70, 40, 40);add(bDivision);bMulti = new Button(*);bMulti.setBackground(Color.green);bMulti.setBounds(110, 70, 40, 40);add(bMulti);

7、bMinus = new Button(-);bMinus.setBackground(Color.green);bMinus.setBounds(155, 70, 40, 40);add(bMinus);b7 = new Button(7);b7.setBounds(20, 115, 40, 40);b7.setBackground(Color.orange);add(b7);b8 = new Button(8);b8.setBackground(Color.orange);b8.setBounds(65, 115, 40, 40);add(b8);b9 = new Button(9);b9

8、.setBackground(Color.orange);b9.setBounds(110, 115, 40, 40);add(b9);bPlus = new Button(+);bPlus.setBackground(Color.green);bPlus.setBounds(155, 115, 40, 85);add(bPlus);b4 = new Button(4);b4.setBackground(Color.orange);b4.setBounds(20, 160, 40, 40);add(b4);b5 = new Button(5);b5.setBackground(Color.or

9、ange);b5.setBounds(65, 160, 40, 40);add(b5);b6 = new Button(6);b6.setBackground(Color.orange);b6.setBounds(110, 160, 40, 40);add(b6);b1 = new Button(1);b1.setBackground(Color.orange);b1.setBounds(20, 205, 40, 40);add(b1);b2 = new Button(2);b2.setBackground(Color.orange);b2.setBounds(65, 205, 40, 40)

10、;add(b2);b3 = new Button(3);b3.setBackground(Color.orange);b3.setBounds(110, 205, 40, 40);add(b3);bEqual = new Button(=);bEqual.setBackground(Color.green);bEqual.setBounds(155, 205, 40, 85);add(bEqual);b0 = new Button(0);b0.setBackground(Color.orange);b0.setBounds(20, 250, 85, 40);add(b0);bPoint = n

11、ew Button(.);bPoint.setBackground(Color.orange);bPoint.setBounds(110, 250, 40, 40);add(bPoint);public boolean action(Event e, Object o) / 實(shí)現(xiàn)事件處理的方法String s = new String();if (e.target = b0) | (e.target = b1) | (e.target = b2)| (e.target = b3) | (e.target = b4) | (e.target = b5)| (e.target = b6) | (e

12、.target = b7) | (e.target = b8)| (e.target = b9) / 獲取數(shù)字按鈕數(shù)據(jù)并在控制臺和文本框輸出if (e.target != bPoint) / 獲取數(shù)字s = (String) o;doForeScreen(s);if (e.target = bPoint) & !ForeScreen.contains(.) / 保證原數(shù)不含小數(shù)點(diǎn)的情況下獲取小數(shù)點(diǎn)并在控制臺和文本框輸出s = (String) o;if (ForeScreen.equals()/ 原來沒有輸入數(shù)據(jù)則用0.doForeScreen(0.); else/ 原來有輸入數(shù)據(jù)則用.doF

13、oreScreen(s);if (e.target = bClear) / 清除按鈕進(jìn)行清除操作doClear();if (e.target = bMulti) | (e.target = bDivision)| (e.target = bPlus) | (e.target = bMinus)| (e.target = bEqual) / 加減乘除等于按鈕獲取運(yùn)算操作符并進(jìn)行運(yùn)算操作if (ForeScreen != ) / 重新輸入數(shù)字進(jìn)行運(yùn)算操作OperatorCurrent = (String) o);doOperator(); else / 沒有重新輸入數(shù)字則作為上一運(yùn)算符-保證不輸入

14、連續(xù)的同一運(yùn)算符OperatorPre = (String) o);return true;public void doOperator() / 運(yùn)算及運(yùn)算結(jié)果輸出操作double dFore, dBack;Double d;if (OperatorPre.equals() / 上一運(yùn)算符沒有則直接輸出BackScreen = ForeScreen;/ 輸入的數(shù)據(jù)轉(zhuǎn)入后臺并清空，用后臺輸出它ForeScreen = ;tfAnswer.setText(BackScreen);repaint(); else / 上一運(yùn)算符存在則運(yùn)算后輸出dFore = (new Double(ForeScree

15、n).doubleValue();dBack = (new Double(BackScreen).doubleValue();ForeScreen = ;/ 運(yùn)算結(jié)果轉(zhuǎn)入后臺并清空，用后臺輸出它BackScreen = tfAnswer.getText();if (OperatorPre.equals(+) d = new Double(dBack + dFore);BackScreen = d.toString();if (OperatorPre.equals(-) d = new Double(dBack - dFore);BackScreen = d.toString();if (Ope

16、ratorPre.equals(*) d = new Double(dBack * dFore);BackScreen = d.toString();if (OperatorPre.equals(/) d = new Double(dBack / dFore);BackScreen = d.toString();tfAnswer.setText(BackScreen);repaint();OperatorPre = OperatorCurrent;/ 現(xiàn)運(yùn)算符變上一運(yùn)算符repaint();public void doForeScreen(String s) / 數(shù)字和小數(shù)點(diǎn)輸出到文本框操作F

17、oreScreen += s;if (ForeScreen.length() 1 & ForeScreen.startsWith(0)& !ForeScreen.contains(.)/ 以0開頭的長度大于一的非小數(shù)去掉開頭的0ForeScreen = ForeScreen.substring(1);tfAnswer.setText(ForeScreen);repaint();public void doClear() / 清空操作OperatorCurrent = ;OperatorPre = ;ForeScreen = 0;BackScreen = ;isFloat = false;tfAnswer.setText(ForeScreen);repaint();Html代碼：JavaApplet計(jì)算器五、測試數(shù)據(jù)及其結(jié)果分析1正常輸入：1.88+99= C .666/33= C 7.33*26= 0.5-1-3= 2結(jié)果：輸出正常。六、調(diào)試過程中的問題 1、一開始計(jì)算器只能在按等號后實(shí)現(xiàn)運(yùn)算沒考慮