java实现的计算器功能示例【基于swing组件】
发布时间:2020-12-14 20:15:41 所属栏目:Java 来源:网络整理
导读:本篇章节讲解java实现的计算器功能。供大家参考研究具体如下: package awtDemo;import java.awt.BorderLayout;import java.awt.Color;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;impor
本篇章节讲解java实现的计算器功能。分享给大家供大家参考,具体如下: package awtDemo; import java.awt.BorderLayout; import java.awt.Color; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; @SuppressWarnings("serial") public class Calculator extends JFrame implements ActionListener { private final String[] KEYS = { "7","8","9","/","sqrt","4","5","6","*","%","1","2","3","-","1/x","0","+/-",".","+","=" }; private final String[] COMMAND = { "Backspace","CE","C" }; private JButton keys[] = new JButton[KEYS.length]; private JButton commands[] = new JButton[COMMAND.length]; private JTextField resultText = new JTextField("0"); private boolean firstDigit = true; private double resultNum = 0.0; private String operator = "="; private boolean operateValidFlag = true; public Calculator() { init(); this.setBackground(Color.LIGHT_GRAY); this.setTitle("www.aspzz.cn - 计算器"); this.setLocation(500,300); this.setResizable(false); this.pack(); } private void init() { resultText.setHorizontalAlignment(JTextField.RIGHT); resultText.setEditable(false); resultText.setBackground(Color.white); JPanel calckeysPanel = new JPanel(); calckeysPanel.setLayout(new GridLayout(4,5,3,3)); for (int i = 0; i < KEYS.length; i++) { keys[i] = new JButton(KEYS[i]); calckeysPanel.add(keys[i]); keys[i].setForeground(Color.blue); } keys[3].setForeground(Color.red); keys[8].setForeground(Color.red); keys[13].setForeground(Color.red); keys[18].setForeground(Color.red); keys[19].setForeground(Color.red); JPanel commandsPanel = new JPanel(); commandsPanel.setLayout(new GridLayout(1,3)); for (int i = 0; i < COMMAND.length; i++) { commands[i] = new JButton(COMMAND[i]); commandsPanel.add(commands[i]); commands[i].setForeground(Color.red); } JPanel panel1 = new JPanel(); panel1.setLayout(new BorderLayout(3,3)); panel1.add("North",commandsPanel); panel1.add("West",calckeysPanel); JPanel top = new JPanel(); top.setLayout(new BorderLayout()); top.add("Center",resultText); getContentPane().setLayout(new BorderLayout(3,5)); getContentPane().add("North",top); getContentPane().add("Center",panel1); for (int i = 0; i < KEYS.length; i++) { keys[i].addActionListener(this); } for (int i = 0; i < COMMAND.length; i++) { commands[i].addActionListener(this); } } public void actionPerformed(ActionEvent e) { String label = e.getActionCommand(); if (label.equals(COMMAND[0])) { handleBackspace(); } else if (label.equals(COMMAND[1])) { resultText.setText("0"); } else if (label.equals(COMMAND[2])) { handleC(); } else if ("0123456789.".indexOf(label) >= 0) { handleNumber(label); } else { handleOperator(label); } } private void handleBackspace() { String text = resultText.getText(); int i = text.length(); if (i > 0) { text = text.substring(0,i - 1); if (text.length() == 0) { resultText.setText("0"); firstDigit = true; operator = "="; } else { resultText.setText(text); } } } private void handleNumber(String key) { if (firstDigit) { resultText.setText(key); } else if ((key.equals(".")) && (resultText.getText().indexOf(".") < 0)) { resultText.setText(resultText.getText() + "."); } else if (!key.equals(".")) { resultText.setText(resultText.getText() + key); } firstDigit = false; } private void handleC() { resultText.setText("0"); firstDigit = true; operator = "="; } private void handleOperator(String key) { if (operator.equals("/")) { if (getNumberFromText() == 0.0) { operateValidFlag = false; resultText.setText("除数不能为零"); } else { resultNum /= getNumberFromText(); } } else if (operator.equals("1/x")) { if (resultNum == 0.0) { operateValidFlag = false; resultText.setText("零没有倒数"); } else { resultNum = 1 / resultNum; } } else if (operator.equals("+")) { resultNum += getNumberFromText(); } else if (operator.equals("-")) { resultNum -= getNumberFromText(); } else if (operator.equals("*")) { resultNum *= getNumberFromText(); } else if (operator.equals("sqrt")) { resultNum = Math.sqrt(resultNum); } else if (operator.equals("%")) { resultNum = resultNum / 100; } else if (operator.equals("+/-")) { resultNum = resultNum * (-1); } else if (operator.equals("=")) { resultNum = getNumberFromText(); } if (operateValidFlag) { long t1; double t2; t1 = (long) resultNum; t2 = resultNum - t1; if (t2 == 0) { resultText.setText(String.valueOf(t1)); } else { resultText.setText(String.valueOf(resultNum)); } } operator = key; firstDigit = true; operateValidFlag = true; } private double getNumberFromText() { double result = 0; try { result = Double.valueOf(resultText.getText()).doubleValue(); } catch (NumberFormatException e) { } return result; } public static void main(String args[]) { Calculator calculator1 = new Calculator(); calculator1.setVisible(true); calculator1.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE); } } 运行效果: PS:这里再为大家推荐几款计算工具供大家进一步参考借鉴: 在线一元函数(方程)求解计算工具: 科学计算器在线使用_高级计算器在线计算: 在线计算器_标准计算器: 更多关于java算法相关内容感兴趣的读者可查看本站专题:《Java数据结构与算法教程》、《Java操作DOM节点技巧总结》、《Java文件与目录操作技巧汇总》和《Java缓存操作技巧汇总》 希望本文所述对大家java程序设计有所帮助。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
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