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Re:问一个菜鸟问题 [Re:dickran]

lisliefor

发贴: 287
积分: 7

于 2006-05-28 19:15

写得不错～
修改的地方我都加了注释，自己看吧！

package help;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

/**
* 
* Title:
* 
* 
* Description:
* 
* 
* Copyright: Copyright 2006
* 
* 
* Company:
* 
*
* @author unascribed
* @version 1.0
*/

public class Frame1 extends Frame implements ActionListener {
 TextField t = new TextField("", 15);
 Panel p1 = new Panel();
 Button[] b = new Button[10];
 Button bAdd = new Button("+");
 Button bSub = new Button("-");
 Button bMul = new Button("*");
 Button bDiv = new Button("/");
 Button bPoint = new Button(".");
 Button bEqual = new Button("=");
 Button bNull = new Button("清空");

 //菜单条、菜单、菜单项
 MenuBar bar = new MenuBar();
 Menu menu = new Menu("Mmenu");
 MenuItem abourt = new MenuItem("Abourt");
 MenuItem help = new MenuItem("Help");

 String str1 = "";
 String str2 = "";
 String operator = null;

 boolean first = true;
 int countOper = 0;
 double result = 0.0;
 double num1 = 0.0, num2 = 0.0;
 boolean error = false;

 public Frame1() {
 t.setEditable(false);
 for (int i = 0; i < b.length; i++) {
 b[i] = new Button((i+1)+""); //这里我小改动了一下
 p1.add(b[i]);
 b[i].setActionCommand("number");
 b[i].addActionListener(this);
 }
 p1.add(bPoint);
 bPoint.setActionCommand("number");
 p1.add(bAdd);
 p1.add(bSub);
 p1.add(bMul);
 p1.add(bDiv);
 p1.add(bEqual);
 p1.add(bNull);
 bAdd.setActionCommand("oper");
 bSub.setActionCommand("oper");
 bMul.setActionCommand("oper");
 bDiv.setActionCommand("oper");
 bAdd.addActionListener(this);
 bSub.addActionListener(this);
 bMul.addActionListener(this);
 bDiv.addActionListener(this);
 bPoint.addActionListener(this);
 bEqual.addActionListener(this);
 bNull.addActionListener(this);
 p1.setLayout(new GridLayout(4, 4, 5, 5));
 add(t, "North");
 add(p1, "Center");
 setLocation(400, 200);
 setSize(200, 200);
 setBackground(Color.lightGray);
 setVisible(true);

 //自己给abourt、help添加监听器，实现你想的功能
 setMenuBar(bar);
 bar.add(menu);
 menu.add(abourt);
 menu.add(help);

 addWindowListener(new WindowAdapter() {
 public void windowClosing(WindowEvent e) {
 System.exit(0);
 }
 });
 }

 public void actionPerformed(ActionEvent e) {
 Button temp = (Button) e.getSource();
 if (e.getActionCommand().equals("number")) {
 if (first) {
 str1 = str1 + temp.getLabel();
 t.setText(str1);
 } else {
 str2 = str2 + temp.getLabel();
 t.setText(str2);
 }
 } else if (e.getActionCommand().equals("oper")) {
 if (str1 == "") {
 countOper = 0;
 first = true;
 } else {
 countOper++;
 if (countOper > 1) {
 getResult();
 }
 operator = temp.getLabel();
 first = false;
 }
 } else if (e.getActionCommand().equals("清空")) {
 str1 = "";
 str2 = "";
 t.setText("");
 countOper = 0;
 first = true;
 error = false;
 } else if (e.getActionCommand().equals("=")) {
 if ((str1 == "") || (str2 == "")) {
 countOper = 0;
 first = true;
 } else {
 getResult();
 countOper = 0;
 }
 }
 }

 public void getResult() {
 num1 = Double.parseDouble(str1);
 num2 = Double.parseDouble(str2);
 if (operator.equals("+")) {
 result = num1 + num2;
 } else if (operator.equals("-")) {
 result = num1 - num2;
 } else if (operator.equals("*")) {
 result = num1 * num2;
 } else if (operator.equals("/")) {
 if (num2 == 0.0) {
 error = true;
 } else {
 result = num1 / num2;
 }
 }
 if (error) {
 t.setText("error");
 } else {
 t.setText(String.valueOf(result));
 str1 = String.valueOf(result);
 str2 = "";
 }
 }

 public static void main(String[] args) {
 new Frame1();
 }

}

话题树型展开

人气	标题	作者	字数	发贴时间
6263	问一个菜鸟问题	dickran	3559	2006-05-28 11:52
5256	Re:问一个菜鸟问题	lisliefor	3807	2006-05-28 19:15
5316	Re:问一个菜鸟问题	dickran	5	2006-05-30 14:59

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