import javax.swing.*;
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import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.HashMap;
/**
* 我的計(jì)算器。Cheshi 繼承于 JFrame，是計(jì)算器的界面
c*/
public class Cheshi extends JFrame {
private Border border = BorderFactory.createEmptyBorder(5, 5, 5, 5);
private JTextField textbox = new JTextField("0");
private CalculatorCore core = new CalculatorCore();
private ActionListener listener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton b = (JButton) e.getSource();
String label = b.getText();
String result = core.process(label);
textbox.setText(result);
}
};
public Cheshi(String title) throws HeadlessException {
super(title); // 調(diào)用父類構(gòu)造方法
setupFrame(); // 調(diào)整窗體屬性
setupControls(); // 創(chuàng)建控件
}
private void setupControls() {
setupDisplayPanel(); // 創(chuàng)建文本面板
setupButtonsPanel(); // 創(chuàng)建按鈕面板
}
// 創(chuàng)建按鈕面板并添加按鈕
private void setupButtonsPanel() {
JPanel panel = new JPanel();
panel.setBorder(border);
panel.setLayout(new GridLayout(4, 5, 3, 3));
createButtons(panel, new String[]{
"7", "8", "9", "+", "C",
"4", "5", "6", "-", "CE",
"1", "2", "3", "*", "", // 空字符串表示這個(gè)位置沒有按鈕
"0", ".", "=", "/", ""
});
this.add(panel, BorderLayout.CENTER);
}
/**
* 在指定的面板上創(chuàng)建按鈕
*
* @param panel 要?jiǎng)?chuàng)建按鈕的面板
* @param labels 按鈕文字
*/
private void createButtons(JPanel panel, String[] labels) {
for (String label : labels) {
// 如果 label 為空，則表示創(chuàng)建一個(gè)空面板。否則創(chuàng)建一個(gè)按鈕。
if (label.equals("")) {
panel.add(new JPanel());
} else {
JButton b = new JButton(label);
b.addActionListener(listener); // 為按鈕添加偵聽器
panel.add(b);
}
}
}
// 設(shè)置顯示面板，用一個(gè)文本框來作為計(jì)算器的顯示部分。
private void setupDisplayPanel() {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.setBorder(border);
setupTextbox();
panel.add(textbox, BorderLayout.CENTER);
this.add(panel, BorderLayout.NORTH);
}
// 調(diào)整文本框
private void setupTextbox() {
textbox.setHorizontalAlignment(JTextField.RIGHT); // 文本右對齊
textbox.setEditable(false); // 文本框只讀
textbox.setBackground(Color.white); // 文本框背景色為白色
}
// 調(diào)整窗體
private void setupFrame() {
this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 當(dāng)窗體關(guān)閉時(shí)程序結(jié)束
this.setLocation(100, 50); // 設(shè)置窗體顯示在桌面上的位置
this.setSize(300, 200); // 設(shè)置窗體大小
this.setResizable(false); // 窗體大小固定
}
// 程序入口
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
Cheshi frame = new Cheshi("我的計(jì)算器");
frame.setVisible(true); // 在桌面上顯示窗體
}
}
/**
* 計(jì)算器核心邏輯。這個(gè)邏輯只能處理 1~2 個(gè)數(shù)的運(yùn)算。
*/
class CalculatorCore {
private String displayText = "0"; // 要顯示的文本
boolean reset = true;
private BigDecimal number1, number2;
private String operator;
private HashMapString, Operator operators = new HashMapString, Operator();
private HashMapString, Processor processors = new HashMapString, Processor();
CalculatorCore() {
setupOperators();
setupProcessors();
}
// 為每種命令添加處理方式
private void setupProcessors() {
processors.put("[0-9]", new Processor() {
public void calculate(String command) {
numberClicked(command);
}
});
processors.put("\\.", new Processor() {
public void calculate(String command) {
dotClicked();
}
});
processors.put("=", new Processor() {
public void calculate(String command) {
equalsClicked();
}
});
processors.put("[+\\-*/]", new Processor() {
public void calculate(String command) {
operatorClicked(command);
}
});
processors.put("C", new Processor() {
public void calculate(String command) {
clearClicked();
}
});
processors.put("CE", new Processor() {
public void calculate(String command) {
clearErrorClicked();
}
});
}
// 為每種 operator 添加處理方式
private void setupOperators() {
operators.put("+", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.add(number2);
}
});
operators.put("-", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.subtract(number2);
}
});
operators.put("*", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.multiply(number2);
}
});
operators.put("/", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.divide(number2, 30, RoundingMode.HALF_UP);
}
});
}
// 根據(jù)命令處理。這里的命令實(shí)際上就是按鈕文本。
public String process(String command) {
for (String pattern : processors.keySet()) {
if (command.matches(pattern)) {
processors.get(pattern).calculate(command);
break;
}
}
return displayText;
}
// 當(dāng)按下 CE 時(shí)
private void clearErrorClicked() {
if (operator == null) {
number1 = null;
} else {
number2 = null;
}
displayText = "0";
reset = true;
}
// 當(dāng)按下 C 時(shí)，將計(jì)算器置為初始狀態(tài)。
private void clearClicked() {
number1 = null;
number2 = null;
operator = null;
displayText = "0";
reset = true;
}
// 當(dāng)按下 = 時(shí)
private void equalsClicked() {
calculateResult();
number1 = null;
number2 = null;
operator = null;
reset = true;
}
// 計(jì)算結(jié)果
private void calculateResult() {
number2 = new BigDecimal(displayText);
Operator oper = operators.get(operator);
if (oper != null) {
BigDecimal result = oper.process(number1, number2);
displayText = result.toString();
}
}
// 當(dāng)按下 +-*/ 時(shí)（這里也可以擴(kuò)展成其他中間操作符）
private void operatorClicked(String command) {
if (operator != null) {
calculateResult();
}
number1 = new BigDecimal(displayText);
operator = command;
reset = true;
}
// 當(dāng)按下 . 時(shí)
private void dotClicked() {
if (displayText.indexOf(".") == -1) {
displayText += ".";
} else if (reset) {
displayText = "0.";
}
reset = false;
}
// 當(dāng)按下 0-9 時(shí)
private void numberClicked(String command) {
if (reset) {
displayText = command;
} else {
displayText += command;
}
reset = false;
}
// 運(yùn)算符處理接口
interface Operator {
BigDecimal process(BigDecimal number1, BigDecimal number2);
}
// 按鈕處理接口
interface Processor {
void calculate(String command);
}
}
你貼的代碼不全，只能給你代碼意思
String
str=e.getActionCommand().trim();//按鈕監(jiān)聽獲得的值，trim是去空格
if("0123456789.".indexOf(str)!=-1)//判斷0到9內(nèi)是否包含str這個(gè)數(shù)
{
if(jtf.getText().equals("0"))jtf.setText(null);//如果jtf(輸入框)獲取到的值=0，則設(shè)置jtf為空
jtf.setText(jtf.getText()+str);//否則設(shè)置jtf的值=jtf的值+str的值
return;
}
我給你找找
package com.bj.calcultor;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Calcultor extends Frame implements ActionListener {
public static void main(String[] args) {//定義主方
new Calcultor();//創(chuàng)建匿名對象，并調(diào)用test()方法;
}
//定義按鈕名稱
String[] arr={"1","2","3","4","5","6","7","8","9","0","+","-","*","/","=","."};
JButton [] button=new JButton[arr.length];
JButton reset = new JButton("CE");
JTextField display = new JTextField(20);
//創(chuàng)建窗口，定義組件
//執(zhí)行窗口事件:關(guān)閉窗口
private class WindowCloser extends WindowAdapter {
public void windowClosing(WindowEvent we) {
System.exit(0);
}
}
public Calcultor(){
super("計(jì)算器");//定義標(biāo)題
//定義面板容器，并布局
JPanel jpanel=new JPanel(new GridLayout(4,4));
//添加按鈕，并給按鈕添加名稱
for (int i = 0; i arr.length; i++) {
button[i]= new JButton(arr[i]);
jpanel.add(button[i]);
}
JPanel panel2 = new JPanel();
panel2.add("Northr", display);
display.setEnabled(false);
panel2.add("East", reset);
this.add("North", panel2);
this.add("Center", jpanel);
for (int i = 0; i arr.length; i++){
addWindowListener(new WindowCloser());
setVisible(true);
setSize(400,400);
pack();
button[i].addActionListener(this);
reset.addActionListener(this);
display.addActionListener(this);
}
}
@Override
public void actionPerformed(ActionEvent e) {//定義事件
// TODO Auto-generated method stub
Object target=e.getSource();
String lable=e.getActionCommand();
if(target==reset){
handleReset();
}else if("0123456789.".indexOf(lable)0){
handleNumber(lable);
}else{
hadleOperator(lable);
}
}
boolean isFirstDigit=true;
private void hadleOperator(String key) {
if(operator.equals("+")){
number += Double.valueOf(display.getText());
}else if (operator.equals("-")){
number -= Double.valueOf(display.getText());
}else if (operator.equals("*")){
number *= Double.valueOf(display.getText());
}else if (operator.equals("/")){
number /= Double.valueOf(display.getText());
}else if(operator.equals("=")){
number =Double.valueOf(display.getText());
}
display.setText(String.valueOf(number));
operator=key;
isFirstDigit=true;
}
private void handleNumber(String key) {
if(true){
display.setText(key);//把鍵值設(shè)置為文本框內(nèi)容
}else if(key.equals(".") display.getText().indexOf(".")0){
display.setText(display.getText()+".");//把文本框內(nèi)容設(shè)置：display.getText()+"."
}else if(!key.equals(".")){
display.setText(display.getText() + key);//把文本框內(nèi)容設(shè)置：display.getText()+key
isFirstDigit=false;
}
}
private void handleReset() {
display.setText("0");
isFirstDigit=true;
operator="=";
}
String operator="=";
Double number=0.0;
}
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