Java设计计算器

最新问答

• 济南别墅装修

  ****************************************************************

  写了一天，终于写完了。

  ****************************************************************

  说明：

  类Calc.java出了界面符合你的要求外，还有以下优点：

  1. 对输入内容进行校验，如果是非法字符（如字母），不响应键盘，而且单个文本框只能输入一个小数点；

  2. 使用Windows界面风格；

  3. 采用大数计算，更精准；

  4. 其它……

  ****************************************************************

  代如下：

  ****************************************************************

  import java.awt.BorderLayout;

  import java.awt.Dimension;

  import java.awt.FlowLayout;

  import java.awt.Toolkit;

  import java.awt.event.ActionEvent;

  import java.awt.event.ActionListener;

  import java.awt.event.KeyAdapter;

  import java.awt.event.KeyEvent;

  import java.math.BigDecimal;

  import javax.swing.JButton;

  import javax.swing.JFrame;

  import javax.swing.JLabel;

  import javax.swing.JMenu;

  import javax.swing.JMenuBar;

  import javax.swing.JMenuItem;

  import javax.swing.JOptionPane;

  import javax.swing.JPanel;

  import javax.swing.JTextField;

  import javax.swing.UIManager;

  /**

  * @author Godwin

  * @version 2010-05-16

  */

  public class Calc extends JFrame implements ActionListener {

  JTextField number1Text;

  JTextField number2Text;

  JTextField resultText;

  public Calc() {

  this.setTitle("计算器");

  /*

  * 菜单栏

  */

  // Operation菜单

  JMenuItem addMenuItem = new JMenuItem("Add");

  addMenuItem.setMnemonic('a');

  JMenuItem subtractMenuItem = new JMenuItem("Subtract");

  subtractMenuItem.setMnemonic('s');

  JMenuItem multiplyMenuItem = new JMenuItem("Multiply");

  multiplyMenuItem.setMnemonic('m');

  JMenuItem divideMenuItem = new JMenuItem("Divide");

  divideMenuItem.setMnemonic('d');

  JMenu operationFile = new JMenu("Operation");

  operationFile.setMnemonic('o');

  operationFile.add(addMenuItem);

  operationFile.add(subtractMenuItem);

  operationFile.add(multiplyMenuItem);

  operationFile.add(divideMenuItem);

  // Exit菜单

  JMenu exitMenu = new JMenu("Exit");

  exitMenu.setMnemonic('x');

  JMenuItem exitItem = new JMenuItem("Exit");

  exitItem.setMnemonic('x');

  exitItem.addActionListener(new ExitActionListener());

  exitMenu.add(exitItem);

  // Operation和Exit菜单

  JMenuBar menubar = new JMenuBar();

  menubar.add(operationFile);

  menubar.add(exitMenu);

  /*

  * 作数和结果

  */

  JLabel number1Label = new JLabel("Number 1");

  number1Text = new JTextField(6);

  JLabel number2Label = new JLabel("Number 2");

  number2Text = new JTextField(6);

  JLabel resultLabel = new JLabel("Result");

  resultText = new JTextField(10);

  resultText.setEditable(false);

  JPanel operandPanel = new JPanel(new FlowLayout());

  operandPanel.add(number1Label);

  operandPanel.add(number1Text);

  operandPanel.add(number2Label);

  operandPanel.add(number2Text);

  operandPanel.add(resultLabel);

  operandPanel.add(resultText);

  /*

  * 作符

  */

  JButton addButton = new JButton("Add");

  JButton subtractButton = new JButton("Subtract");

  JButton multiplyButton = new JButton("Multiply");

  JButton divideButton = new JButton("Divide");

  JPanel operatorPanel = new JPanel(new FlowLayout());

  operatorPanel.add(addButton);

  operatorPanel.add(subtractButton);

  operatorPanel.add(multiplyButton);

  operatorPanel.add(divideButton);

  /*

  * 所有面板

  */

  this.add(menubar, BorderLayout.NORTH);

  this.add(operandPanel, BorderLayout.CENTER);

  this.add(operatorPanel, BorderLayout.SOUTH);

  this.pack();

  this.setResizable(false);

  Toolkit tool = Toolkit.getDefaultToolkit();

  Dimension screen = tool.getScreenSize();

  this.setLocation(screen.width / 2 - this.getWidth() / 2, screen.height

  / 2 - this.getHeight() / 2);

  this.setVisible(true);

  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  /*

  *

  */

  // 菜单

  addMenuItem.addActionListener(this);

  subtractMenuItem.addActionListener(this);

  multiplyMenuItem.addActionListener(this);

  divideMenuItem.addActionListener(this);

  // 文本框

  number1Text.addKeyListener(new VerifyInputKeyAdapter());

  number2Text.addKeyListener(new VerifyInputKeyAdapter());

  // 按钮

  addButton.addActionListener(this);

  subtractButton.addActionListener(this);

  multiplyButton.addActionListener(this);

  divideButton.addActionListener(this);

  }

  class VerifyInputKeyAdapter extends KeyAdapter {

  public void keyTyped(KeyEvent e) {

  char c = e.getKeyChar();

  System.out.println(c);

  if (!(('0' <= c) && (c <= '9') || (c == KeyEvent.VK_DELETE) || (c == KeyEvent.VK_BACK_SPACE))) {

  if (!((!((JTextField) (e.getSource())).getText().contains(".")) && (c == '.'))) {

  e.consume();

  }

  }

  }

  }

  class ExitActionListener implements ActionListener {

  public void actionPerformed(ActionEvent e) {

  System.exit(0);

  }

  }

  public void actionPerformed(ActionEvent e) {

  String operand1 = number1Text.getText();

  BigDecimal big1 = BigDecimal.valueOf(Double.valueOf(operand1));

  String operand2 = number2Text.getText();

  BigDecimal big2 = BigDecimal.valueOf(Double.valueOf(operand2));

  if ((!(operand1.equals(""))) && (operand1 != null)

  && (!(operand2.equals(""))) && (operand2 != null)) {

  String name = e.getSource().getClass().getSimpleName();

  String operator = "";

  if (name.equals("JButton")) {

  JButton b = (JButton) (e.getSource());

  operator = b.getText();

  } else if (name.equals("JMenuItem")) {

  JMenuItem m = (JMenuItem) e.getSource();

  operator = m.getText();

  }

  if (operator.equals("Add")) {

  resultText.setText(String.valueOf(big1.add(big2)));

  } else if (operator.equals("Subtract")) {

  resultText.setText(String.valueOf(big1.subtract(big2)));

  } else if (operator.equals("Multiply")) {

  resultText.setText(String.valueOf(big1.multiply(big2)));

  } else if (operator.equals("Divide")) {

  resultText.setText(String.valueOf(big1.divide(big2)));

  } else {

  JOptionPane.showMessageDialog(this, "作有误！", "错误提示",

  JOptionPane.WARNING_MESSAGE);

  }

  } else {

  JOptionPane.showMessageDialog(this, "请输入作数！", "错误提示",

  JOptionPane.WARNING_MESSAGE);

  number1Text.requestFocus();

  }

  }

  public static void main(String[] args) throws Exception {

  UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

  new Calc();

  }

  }

  ****************************************************************

  运行结果如下：

  浏览 239赞 73时间 2023-07-01
• 游客小孩儿

  我晕，谁会为你写这么一堆，而且很没意义的代？
  ……

  浏览 215赞 112时间 2023-04-10
• 潘潘吃吃吃啊

  先等着吧，写好了再给你
  有邮箱没？？写好了发给你

  浏览 263赞 130时间 2022-06-11
• wangxinrose

  就这么点要求都100分啊，太简单了

  浏览 210赞 55时间 2022-03-30