JAVA 一个简单的图形界面计算器
来源：互联网 发布：姬存希 知乎 编辑：程序博客网 时间：2024/05/18 00:10
<pre name="code" class="java">package 计算器;import java.awt.EventQueue;import javax.swing.JFrame;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.border.EmptyBorder;import javax.swing.JTextField;import javax.swing.JButton;import java.awt.event.ActionListener;import java.awt.event.ActionEvent;import java.awt.Font;import javax.swing.SwingConstants;import java.awt.Color;import java.awt.Point;import java.awt.Toolkit;public class 计算器 extends JFrame {/** * */private static final long serialVersionUID = 7390993416513457117L;private JPanel contentPane;private JTextField textField;private JButton btnC;// 标志用户按的是否是整个表达式的第一个数字,或者是运算符后的第一个数字 private boolean firstDigit = true; // 计算的中间结果。 private double resultNum = 0.0; // 当前运算的运算符 private String operator = "="; // 操作是否合法 private boolean operateValidFlag = true; //储存临时结果 private double memoryNum = 0.0; //储存变量中是否有值 private boolean isNum = false; /** * Launch the application. */public static void main(String[] args) {EventQueue.invokeLater(new Runnable() {public void run() {try {计算器 frame = new 计算器();frame.setVisible(true);} catch (Exception e) {e.printStackTrace();}}});}/** * 处理在储存键被按下的事件 * * @param key */private void handleMemoryNumber(String key) {if(key.equals("M+")){memoryNum += getNumberFromText(); //获取当前文本框中的数字，并储存isNum = true; //改变是否有保存数字的状态为真textField.setText("0"); //清除文本框显示内容 firstDigit = true; //设置首位数字为真 resultNum = 0.0; //设置中间结果变量为初始值}else if(key.equals("M-")){if(isNum){ //首先判断储存变量内部是否有值memoryNum -= getNumberFromText(); //有值时用原有的值减去当前获取的值if(memoryNum==0.0){isNum = false; //减完的差为0时，还原是否有储存值状态为假}else{isNum = true; //如果差不为0时，保持储存值状态为真}textField.setText("0"); //设置文本框为0 firstDigit = true; //设置首数字为真 resultNum = 0.0; //清除中间结果变量值为初始值 }else{memoryNum = getNumberFromText(); //储存变量中没有保存数值时，直接获取数值进行保存if(memoryNum==0.0){ //如果其中数值为0，设置是否有储存数变量为假，否则为真isNum = false;}else{isNum = true;}textField.setText("0"); firstDigit = true; resultNum = 0.0; }}else if(key.equals("MR")){ //如果是否储存数据变量为真时，显示储存的数值到文本框，并显示正确的格式if(isNum){long t1; double t2; t1 = (long) memoryNum; t2 = memoryNum - t1; if (t2 == 0) { textField.setText(String.valueOf(t1)); firstDigit = true; } else { textField.setText(String.valueOf(memoryNum)); firstDigit = true; } }else{ textField.setText("0"); //如果是否储存数据变量为假时，清除文本框内容为0 firstDigit = true; }}else if(key.equals("MC")){ memoryNum = 0.0; //清除储存变量中的数值，并设置为初始值isNum = false; //设置是否储存数值变量为初始值textField.setText("0"); //清除文本框显示内容firstDigit = true; resultNum = 0.0;}}/** * 处理数字键被按下的事件 * * @param key */ private void handleNumber(String key) { if (firstDigit) { if (key.equals(".")){ textField.setText("0"+key); }else if(key.equals("0") ){ //在首位数字状态时，如果按下的是零键，除非是输入第二位操作数时显示为“0”，否则忽略按键操作 //如果是输入第二个操作数时，按下首位的零给予显示 if(operator.equals("-") || operator.equals("+") || operator.equals("*") || operator.equals("/")|| operator.equals("=")){ textField.setText(key); }else{ return; //如果首位数字按下的是零键时进行忽略 } }else{ // 输入的第一个数字 textField.setText(key); } } else if ((key.equals(".")) && (textField.getText().indexOf(".") < 0)) { // 输入的是小数点，并且之前没有小数点，则将小数点附在结果文本框的后面 textField.setText(textField.getText() + "."); } else if(key.equals("0")){ //非首位数字时按下零键，如果首位已经是“0”时，忽略本次按键操作，否则正常给后位增加“0” if(textField.getText().equals("0")){ return; }else{ textField.setText(textField.getText() + key); } } else if (!key.equals(".")&&!key.equals("0")) { //按下的键非小数点和0键时，如果首位已经是“0”，用输入键的数字代替首位数字的“0”，否则在原内容后增加“0” if(textField.getText().equals("0")){ textField.setText(key); }else{ // 如果输入的不是小数点，则将数字附在结果文本框的后面 textField.setText(textField.getText() + key); } } // 以后输入的肯定不是第一个数字了 firstDigit = false; } /** * 处理单独的操作符键 * * @param key */private void handleOperatorOne(String key) {if(textField.getText().equals("除数不能为零，请重新计算") || textField.getText().equals("零没有倒数")){ return; }else{ double Num = getNumberFromText(); switch(key){ case "+/-": //正负号运算 resultNum = Num*(-1); operateValidFlag(); firstDigit = true; break; case "sqrt":// 平方根运算 resultNum = Math.sqrt(Num); operateValidFlag(); firstDigit = true; break; case "%":// 百分号运算，除以100 resultNum = Num / 100; operateValidFlag(); firstDigit = true; break; case "1/x":// 倒数运算 if (Num == 0.0) { // 操作不合法 textField.setText("零没有倒数"); firstDigit = true; break; } else { resultNum = 1 / Num; operateValidFlag(); firstDigit = true; break; } default: break; } } } /** * 处理运算符键被按下的事件 * * @param key */ private void handleOperator(String key) { if(textField.getText().equals("除数不能为零，请重新计算") || textField.getText().equals("零没有倒数")){ resultNum = 0.0; textField.setText("0"); operateValidFlag = false; }else if (operator.equals("/")) { // 除法运算 // 如果当前结果文本框中的值等于0 if (getNumberFromText() == 0.0) { // 操作不合法 operateValidFlag = false; textField.setText("除数不能为零，请重新计算"); resultNum = 0.0; } else { resultNum /= getNumberFromText(); } }else if (operator.equals("+")) { // 加法运算 resultNum += getNumberFromText(); } else if (operator.equals("-")) { // 减法运算 resultNum -= getNumberFromText(); } else if (operator.equals("*")) { // 乘法运算 resultNum *= getNumberFromText(); } else if (operator.equals("=")) { // 赋值运算 resultNum = getNumberFromText(); } if (operateValidFlag) { operateValidFlag(); } // 运算符等于用户按的按钮 operator = key; firstDigit = true; operateValidFlag = true; } /* * 操作有效时输出格式正确的值 */private void operateValidFlag(){long t1; double t2; t1 = (long) resultNum; t2 = resultNum - t1; if (t2 == 0) { textField.setText(String.valueOf(t1)); } else { textField.setText(String.valueOf(resultNum)); }} /** * 从结果文本框中获取数字 * * @return */ private double getNumberFromText() { double result = 0; try { result = Double.valueOf(textField.getText()).doubleValue(); } catch (NumberFormatException e) { JOptionPane.showMessageDialog(null, e); } return result; }/** * 处理按键C的处理方法 */ private void handleC() {/** * 处理C键被按下的事件 */ // 初始化计算器的各种值textField.setText("0");resultNum = 0.0; firstDigit = true; operator = "="; } /** * 处理Backspace键的方法 */private void handleBackspace() {// TODO 自动生成的方法存根String text = textField.getText(); int i = text.length(); if (i > 0) { // 退格，将文本最后一个字符去掉 text = text.substring(0, i - 1); if (text.length() == 0) { // 如果文本没有了内容，则初始化计算器的各种值 textField.setText("0"); firstDigit = true; operator = "="; } else { // 显示新的文本 textField.setText(text); } }}/** * 处理CE键的方法 */private void handleCE(){// 用户按了"CE"键textField.setText("0");firstDigit = true;}/** * Create the frame. */public 计算器() {setIconImage(Toolkit.getDefaultToolkit().getImage(getClass().getResource("/calc.png")));setResizable(false);setLocation(new Point(500, 300));setTitle("\u8BA1\u7B97\u5668 by \u547C\u7F8E\u8FB0 \u9AD8\u65B0\u4E00\u5C0F\u56DB3\u73ED");setBackground(Color.LIGHT_GRAY);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setBounds(100, 100, 506, 380);contentPane = new JPanel();contentPane.setBackground(new Color(255, 153, 102));contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));setContentPane(contentPane);contentPane.setLayout(null);JPanel panel = new JPanel();panel.setBackground(new Color(255, 153, 153));panel.setBounds(10, 10, 481, 332);contentPane.add(panel);panel.setLayout(null);textField = new JTextField();textField.setEditable(false);textField.setForeground(new Color(255, 51, 255));textField.setBackground(Color.WHITE);textField.setHorizontalAlignment(SwingConstants.RIGHT);textField.setFont(new Font("宋体", Font.PLAIN, 24));textField.setText("0");textField.setBounds(16, 16, 446, 36);panel.add(textField);textField.setColumns(10);JButton btnSqrt = new JButton("sqrt");btnSqrt.setFont(new Font("Dialog", Font.PLAIN, 17));btnSqrt.setForeground(new Color(255, 102, 255));btnSqrt.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) { handleOperatorOne(btnSqrt.getText());}});btnSqrt.setBounds(401, 120, 61, 37);panel.add(btnSqrt);JButton button_1 = new JButton("%");button_1.setFont(new Font("Dialog", Font.PLAIN, 17));button_1.setForeground(new Color(255, 102, 255));button_1.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperatorOne(button_1.getText());}});button_1.setBounds(401, 173, 61, 37);panel.add(button_1);JButton button_2 = new JButton("1/x");button_2.setFont(new Font("Dialog", Font.PLAIN, 17));button_2.setForeground(new Color(255, 102, 255));button_2.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperatorOne(button_2.getText());}});button_2.setBounds(401, 226, 61, 37);panel.add(button_2);JButton button_3 = new JButton("/");button_3.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperator(button_3.getText());}});button_3.setFont(new Font("Dialog", Font.PLAIN, 17));button_3.setForeground(new Color(255, 102, 0));button_3.setBounds(324, 120, 61, 37);panel.add(button_3);JButton button_4 = new JButton("*");button_4.setFont(new Font("Dialog", Font.PLAIN, 17));button_4.setForeground(new Color(255, 102, 0));button_4.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperator(button_4.getText());}});button_4.setBounds(324, 173, 61, 37);panel.add(button_4);JButton button_5 = new JButton("-");button_5.setFont(new Font("Dialog", Font.PLAIN, 17));button_5.setForeground(new Color(255, 102, 0));button_5.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperator(button_5.getText());}});button_5.setBounds(324, 226, 61, 37);panel.add(button_5);JButton button_6 = new JButton("+");button_6.setFont(new Font("Dialog", Font.PLAIN, 17));button_6.setForeground(new Color(255, 102, 0));button_6.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperator(button_6.getText());}});button_6.setBounds(324, 279, 61, 37);panel.add(button_6);JButton button_7 = new JButton("9");button_7.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_7.getText());}});button_7.setFont(new Font("Dialog", Font.PLAIN, 17));button_7.setForeground(new Color(255, 51, 255));button_7.setBounds(247, 120, 61, 37);panel.add(button_7);JButton button_8 = new JButton("6");button_8.setFont(new Font("Dialog", Font.PLAIN, 17));button_8.setForeground(new Color(255, 51, 255));button_8.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_8.getText());}});button_8.setBounds(247, 173, 61, 37);panel.add(button_8);JButton button_9 = new JButton("3");button_9.setFont(new Font("Dialog", Font.PLAIN, 17));button_9.setForeground(new Color(255, 51, 255));button_9.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_9.getText());}});button_9.setBounds(247, 226, 61, 37);panel.add(button_9);JButton button_10 = new JButton(".");button_10.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_10.getText());}});button_10.setFont(new Font("Dialog", Font.PLAIN, 17));button_10.setForeground(new Color(255, 51, 255));button_10.setBounds(247, 279, 61, 37);panel.add(button_10);JButton button_11 = new JButton("8");button_11.setFont(new Font("Dialog", Font.PLAIN, 17));button_11.setForeground(new Color(255, 51, 255));button_11.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_11.getText());}});button_11.setBounds(170, 120, 61, 37);panel.add(button_11);JButton button_12 = new JButton("5");button_12.setFont(new Font("Dialog", Font.PLAIN, 17));button_12.setForeground(new Color(255, 51, 255));button_12.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_12.getText());}});button_12.setBounds(170, 173, 61, 37);panel.add(button_12);JButton button_13 = new JButton("2");button_13.setFont(new Font("Dialog", Font.PLAIN, 17));button_13.setForeground(new Color(255, 51, 255));button_13.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_13.getText());}});button_13.setBounds(170, 226, 61, 37);panel.add(button_13);JButton button_14 = new JButton("+/-");button_14.setFont(new Font("Dialog", Font.PLAIN, 17));button_14.setForeground(new Color(255, 102, 0));button_14.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperatorOne(button_14.getText());}});button_14.setBounds(170, 279, 61, 37);panel.add(button_14);JButton button_15 = new JButton("7");button_15.setForeground(new Color(255, 51, 255));button_15.setFont(new Font("Dialog", Font.PLAIN, 17));button_15.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_15.getText());}});button_15.setBounds(93, 120, 61, 37);panel.add(button_15);JButton button_16 = new JButton("4");button_16.setForeground(new Color(255, 51, 255));button_16.setFont(new Font("Dialog", Font.PLAIN, 17));button_16.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_16.getText());}});button_16.setBounds(93, 173, 61, 37);panel.add(button_16);JButton button_17 = new JButton("1");button_17.setForeground(new Color(255, 51, 255));button_17.setFont(new Font("Dialog", Font.PLAIN, 17));button_17.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) { handleNumber(button_17.getText());}});button_17.setBounds(93, 226, 61, 37);panel.add(button_17);JButton button_18 = new JButton("0");button_18.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleNumber(button_18.getText());}});button_18.setForeground(new Color(255, 51, 255));button_18.setFont(new Font("Dialog", Font.PLAIN, 17));button_18.setBounds(93, 279, 61, 37);panel.add(button_18);JButton button = new JButton("=");button.setForeground(new Color(255, 102, 0));button.setFont(new Font("宋体", Font.BOLD, 26));button.setBounds(401, 279, 61, 37);button.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleOperator(button.getText());}});panel.add(button);handleOperator(button.getText());JButton btnMc = new JButton("MC");btnMc.setForeground(new Color(255, 102, 255));btnMc.setFont(new Font("宋体", Font.PLAIN, 15));btnMc.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleMemoryNumber(btnMc.getText());}});btnMc.setBounds(16, 120, 61, 37);panel.add(btnMc);JButton btnMr = new JButton("MR");btnMr.setForeground(new Color(255, 102, 255));btnMr.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleMemoryNumber(btnMr.getText());}});btnMr.setFont(new Font("宋体", Font.PLAIN, 15));btnMr.setBounds(16, 173, 61, 37);panel.add(btnMr);JButton btnMs = new JButton("M-");btnMs.setForeground(new Color(255, 102, 255));btnMs.setFont(new Font("宋体", Font.PLAIN, 15));btnMs.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleMemoryNumber(btnMs.getText());}});btnMs.setBounds(16, 226, 61, 37);panel.add(btnMs);JButton btnM = new JButton("M+");btnM.setForeground(new Color(255, 102, 255));btnM.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleMemoryNumber(btnM.getText());}});btnM.setFont(new Font("宋体", Font.PLAIN, 15));btnM.setBounds(16, 279, 61, 37);panel.add(btnM);btnC = new JButton("C");btnC.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) { handleC();}});btnC.setForeground(new Color(255, 102, 0));btnC.setFont(new Font("宋体", Font.PLAIN, 15));btnC.setBounds(350, 68, 112, 36);panel.add(btnC);JButton btnNewButton = new JButton("CE");btnNewButton.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleCE();}});btnNewButton.setForeground(new Color(255, 102, 0));btnNewButton.setFont(new Font("宋体", Font.PLAIN, 15));btnNewButton.setBounds(226, 68, 112, 36);panel.add(btnNewButton);JButton btnBackspace = new JButton("Backspace");btnBackspace.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {handleBackspace();}});btnBackspace.setForeground(new Color(255, 102, 0));btnBackspace.setFont(new Font("宋体", Font.PLAIN, 15));btnBackspace.setBounds(102, 68, 112, 36);panel.add(btnBackspace);}} 0 0
- JAVA 一个简单的图形界面计算器
- 用JAVA写的一个简单的图形界面计算器
- 创建一个图形界面的计算器
- java图形界面UI设计——简单的计算器
- java图形界面UI设计——简单的计算器
- 利用java做一个简单的计算器
- 一个简单的java计算器源码分析
- 利用java做一个简单的计算器
- 利用java做一个简单的计算器
- 一个简单的Java计算器实现
- 分享一个java写的简单计算器
- 用java编写一个简单的计算器
- JAVA一个超级简单的计算器
- java 写一个简单的计算器
- 一个简单的计算器（Java）
- 基于Java实现的一个简单计算器
- 一个简单的计算器（java）
- 怎样用Java写一个简单的计算器？
- Activity的生命周期（一）
- C++ DirectX 游戏开发初级视频教程 20 资源下载链接
- Activity的生命周期（二）——简单继承父类
- DE26 Continuation: Repeated Real Eigenvalues
- Python图像处理库PIL的ImageEnhance模块介绍
- JAVA 一个简单的图形界面计算器
- 3910: 火车 LCA+并查集
- Activity的生命周期（三）——结合Activity的生命周期理解子类继承父类预加载数据
- Boost MPI send and recv
- 获取UIWebView的高度
- CS0234The type or namespace name 'Mvc' does not exist in the namespace 'Microsoft.AspNet' (are you
- 详解配置java环境变量那点事儿
- 第52课：Hadoop链式MapReduce编程实战
- 心路
