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(gè)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(cè)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(shí)點(diǎn)（包括JAVA Applet和低級(jí)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(gè)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

2、方法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, Ope

3、ratorPre;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 App

4、let 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("");Oper

5、atorPre = new String("");ForeScreen = new String("0");/ 保證輸入字符串不為空防止計(jì)算錯(cuò)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, Fo

6、nt.BOLD, 28);add(tfAnswer);tfAnswer.setText(ForeScreen);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("*&qu

7、ot;);bMulti.setBackground(Color.green);bMulti.setBounds(110, 70, 40, 40);add(bMulti);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);

8、b8 = new Button("8");b8.setBackground(Color.orange);b8.setBounds(65, 115, 40, 40);add(b8);b9 = new Button("9");b9.setBackground(Color.orange);b9.setBounds(110, 115, 40, 40);add(b9);bPlus = new Button("+");bPlus.setBackground(Color.green);bPlus.setBounds(155, 115, 40, 85

9、);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.orange);b5.setBounds(65, 160, 40, 40);add(b5);b6 = new Button("6");b6.setBackground(Color.orange);b6.setBounds(110, 160, 40

10、, 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);add(b2);b3 = new Button("3");b3.setBackground(Color.orange);b3.setBounds(110, 205, 4

11、0, 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 = new Button(".");bPoint.setBackground(Color.orange)

12、;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.target = b7) | (e.target = b8)| (e

13、.target = b9) / 獲取數(shù)字按鈕數(shù)據(jù)并在控制臺(tái)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(tái)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

14、輸入數(shù)據(jù)則用.doForeScreen(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 /

15、沒有重新輸入數(shù)字則作為上一運(yùn)算符->保證不輸入連續(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(tái)并清空，用后臺(tái)輸出它ForeScreen = ""tfAnswer.setText(BackScreen);repaint();

16、else / 上一運(yùn)算符存在則運(yùn)算后輸出dFore = (new Double(ForeScreen).doubleValue();dBack = (new Double(BackScreen).doubleValue();ForeScreen = ""/ 運(yùn)算結(jié)果轉(zhuǎn)入后臺(tái)并清空，用后臺(tái)輸出它BackScreen = tfAnswer.getText();if (OperatorPre.equals("+") d = new Double(dBack + dFore);BackScreen = d.toString();if (OperatorPre.e

17、quals("-") d = new Double(dBack - dFore);BackScreen = d.toString();if (OperatorPre.equals("*") d = new Double(dBack * dFore);BackScreen = d.toString();if (OperatorPre.equals("/") d = new Double(dBack / dFore);BackScreen = d.toString();tfAnswer.setText(BackScreen);repain

18、t();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ForeScreen += 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.substri

19、ng(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：<!DOCTYPE html><html lang="en"><head><meta chars