📄 calculator.java
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import java.awt.*;
import java.lang.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.text.DecimalFormat;
public class Calculator implements ActionListener //导入动作监听接口
{ //设计面板中的单位
JFrame frame;
JTextField textAnswer;
JPanel panel, panel1, panel2, panel3;
JMenuBar mainMenu;
JTextField textMemory;
JLabel labelMemSpace; //labelMemSpace单纯做摆设，控制面板的形状
JButton buttonBk, buttonCe, buttonC;
JButton button[];
JButton buttonMC, buttonMR, buttonMS, buttonMAdd;
JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul,
buttonDiv, buttonMod;
JButton buttonSqrt, buttonDao, buttonEqual;
JMenu editMenu, viewMenu, helpMenu;
JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, topHelp, aboutCal;
DecimalFormat df; //设置数据输出精度
boolean clickable; //控制当前能否按键
double memoryd; //使用内存中存储的数字
int memoryi;
double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd)
short key=-1, prekey=-1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算
String copy; //做复制用
JTextArea help; //帮助
JScrollPane scrollHelp;
public Calculator() //构造函数
{ clickable=true;
answerd=0;
frame=new JFrame("计算器");
df=new DecimalFormat("0.##############"); //设置数据输出精度(对于double型值)
textAnswer=new JTextField(15);
textAnswer.setText("");
textAnswer.setEditable(false);
textAnswer.setBackground(new Color(255, 255, 255));
panel = new JPanel();
frame.getContentPane().add(panel);
panel1 = new JPanel();
panel2 = new JPanel();
panel.setLayout(new BorderLayout());
//设计整个面板
mainMenu = new JMenuBar();
editMenu = new JMenu("编辑(E)");
viewMenu = new JMenu("查看(V)");
helpMenu = new JMenu("帮助(H)");
copyItem = new JMenuItem(" 复制(C) Ctrl+C");
copyItem.addActionListener(this);
pasteItem = new JMenuItem(" 粘贴(V) Ctrl+V");
pasteItem.addActionListener(this);
editMenu.add(copyItem);
editMenu.add(pasteItem);
tItem = new JMenuItem("●标准型(T)");
tItem.addActionListener(this);
sItem = new JMenuItem(" 科学型(S)");
sItem.addActionListener(this);
numberGroup = new JMenuItem(" 数字分组(I)");
numberGroup.addActionListener(this);
viewMenu.add(tItem);
viewMenu.add(sItem);
viewMenu.add(numberGroup);
topHelp = new JMenuItem(" 帮助主题(H)");
topHelp.addActionListener(this);
help = new JTextArea(5, 20);
scrollHelp = new JScrollPane(help);
help.setEditable(false);
help.append("执行简单计算\n");
help.append("1. 键入计算的第一个数字.\n");
help.append("2. 单击'+'执行加、'-'执行减、'*'执行乘或'/'执行除.\n");
help.append("3. 键入计算的下一个数字.\n");
help.append("4. 输入所有剩余的运算符和数字.\n");
help.append("5. 单击'='.\n"); //77hang
aboutCal = new JMenuItem(" 关于计算器(A)");
aboutCal.addActionListener(this);
helpMenu.add(topHelp);
helpMenu.add(aboutCal);
mainMenu.add(editMenu);
mainMenu.add(viewMenu);
mainMenu.add(helpMenu);
panel.add(mainMenu, BorderLayout.NORTH);
panel.add(textAnswer, BorderLayout.CENTER);
panel.add(panel1, BorderLayout.SOUTH);
panel1.setLayout(new BorderLayout());
textMemory = new JTextField(3);
textMemory.setEditable(false);
textMemory.setBackground(new Color(217, 217, 217));
labelMemSpace = new JLabel(" ");
buttonBk = new JButton("Backspace");
buttonBk.setForeground(new Color(255, 0, 0));
buttonCe = new JButton("CE");
buttonCe.setForeground(new Color(255, 0, 0));
buttonC = new JButton("C");
buttonC.setForeground(new Color(255, 0, 0));
buttonBk.addActionListener(this);
buttonCe.addActionListener(this);
buttonC.addActionListener(this);
panel1.add(panel2, BorderLayout.NORTH);
panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
panel2.add(textMemory);
panel2.add(labelMemSpace);
panel2.add(buttonBk);
panel2.add(buttonCe);
panel2.add(buttonC);
panel3 = new JPanel();
panel1.add(panel3, BorderLayout.CENTER);
button = new JButton[10];
for (int i = 0; i < button.length; i++)
{
button[i] = new JButton(Integer.toString(i));
button[i].setForeground(new Color(0, 0, 255));
}
buttonMC = new JButton("MC");
buttonMC.setForeground(new Color(255, 0, 0));
buttonMR = new JButton("MR");
buttonMR.setForeground(new Color(255, 0, 0));
buttonMS = new JButton("MS");
buttonMS.setForeground(new Color(255, 0, 0));
buttonMAdd = new JButton("M+");
buttonMAdd.setForeground(new Color(255, 0, 0));
buttonDot = new JButton(".");
buttonDot.setForeground(new Color(0, 0, 255));
buttonAddAndSub = new JButton("+/-");
buttonAddAndSub.setForeground(new Color(0, 0, 255));
buttonAdd = new JButton("+");
buttonAdd.setForeground(new Color(255, 0, 0));
buttonSub = new JButton("-");
buttonSub.setForeground(new Color(255, 0, 0));
buttonMul = new JButton("*");
buttonMul.setForeground(new Color(255, 0, 0));
buttonDiv = new JButton("/");
buttonDiv.setForeground(new Color(255, 0, 0));
buttonMod = new JButton("%");
buttonMod.setForeground(new Color(0, 0, 255));
buttonSqrt = new JButton("sqrt");
buttonSqrt.setForeground(new Color(0, 0, 255));
buttonDao = new JButton("1/x");
buttonDao.setForeground(new Color(0, 0, 255));
buttonEqual = new JButton("=");
buttonEqual.setForeground(new Color(255, 0, 0));
//将所有行为与监听绑定
panel3.setLayout(new GridLayout(4, 6));
panel3.add(buttonMC);
buttonMC.addActionListener(this);
panel3.add(button[7]);
button[7].addActionListener(this);
panel3.add(button[8]);
button[8].addActionListener(this);
panel3.add(button[9]);
button[9].addActionListener(this);
panel3.add(buttonDiv);
buttonDiv.addActionListener(this);
panel3.add(buttonSqrt);
buttonSqrt.addActionListener(this);
panel3.add(buttonMR);
buttonMR.addActionListener(this);
panel3.add(button[4]);
button[4].addActionListener(this);
panel3.add(button[5]);
button[5].addActionListener(this);
panel3.add(button[6]);
button[6].addActionListener(this);
panel3.add(buttonMul);
buttonMul.addActionListener(this);
panel3.add(buttonMod);
buttonMod.addActionListener(this);
panel3.add(buttonMS);
buttonMS.addActionListener(this);
panel3.add(button[1]);
button[1].addActionListener(this);
panel3.add(button[2]);
button[2].addActionListener(this);
panel3.add(button[3]);
button[3].addActionListener(this);
panel3.add(buttonSub);
buttonSub.addActionListener(this);
panel3.add(buttonDao);
buttonDao.addActionListener(this);
panel3.add(buttonMAdd);
buttonMAdd.addActionListener(this);
panel3.add(button[0]);
button[0].addActionListener(this);
panel3.add(buttonAddAndSub);
buttonAddAndSub.addActionListener(this);
panel3.add(buttonDot);
buttonDot.addActionListener(this);
panel3.add(buttonAdd);
buttonAdd.addActionListener(this);
panel3.add(buttonEqual);
buttonEqual.addActionListener(this);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
frame.pack();
frame.show();
}
//设置各个按钮行为
public void actionPerformed(ActionEvent event)
{
boolean sign = false; //判断是否是double型数参与运算，是为true，不是为false
Object temp = event.getSource();
try {
//如果按下数据按钮，将按下的按钮代表的数据插入的当前文本框字符串之后
for (int i = 0; i <= 9; i++)
if (temp == button[i] && clickable == true)
textAnswer.setText(textAnswer.getText() + Integer.toString(i));
//按下'.'按钮时，判断当前文本框内字符串中含不含'.'，如果已含，则不允许再插入'.'
if (temp == buttonDot && clickable == true)
{
boolean isDot = false;
if (textAnswer.getText().length() == 0)
isDot = true;
for (int i = 0; i < textAnswer.getText().length(); i++)
if ('.' == textAnswer.getText().charAt(i))
{
isDot = true;
break;
}
if (isDot == false)
textAnswer.setText(textAnswer.getText() + ".");
}
if ( (temp == buttonAdd || temp == buttonSub || temp == buttonMul ||
temp == buttonDiv) && clickable == true)
{
//'+'操作
if (temp == buttonAdd)
{
switch (prekey)
{
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0)
{
textAnswer.setText("除数不能为零");
clickable = false;
}
else
answerd /= Double.parseDouble(textAnswer.getText());
break;
default:
answerd = Double.parseDouble(textAnswer.getText());
}//chadaozhelile
textAnswer.setText("");
prekey = key = 0;
}
//'-'操作
if (temp == buttonSub)
{
switch (prekey)
{
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0)
{
textAnswer.setText("除数不能为零");
clickable = false;
}
else
answerd /= Double.parseDouble(textAnswer.getText());
break;
default:
answerd = Double.parseDouble(textAnswer.getText());
}
textAnswer.setText("");
prekey = key = 1;
}
//'*'操作
if (temp == buttonMul)
{
switch (prekey)
{
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0)
{
textAnswer.setText("除数不能为零");
clickable = false;
}
else
answerd /= Double.parseDouble(textAnswer.getText());
break;
default:
answerd = Double.parseDouble(textAnswer.getText());
}
textAnswer.setText("");
prekey = key = 2;
}
//'/'操作
if (temp == buttonDiv)
{
switch (prekey)
{
case 0:
answerd += Double.parseDouble(textAnswer.getText());
break;
case 1:
answerd -= Double.parseDouble(textAnswer.getText());
break;
case 2:
answerd *= Double.parseDouble(textAnswer.getText());
break;
case 3:
if (Double.parseDouble(textAnswer.getText()) == 0)
{
textAnswer.setText("除数不能为零");
clickable = false;
}
else
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