Java swing实现的计算器功能完整实例

package awtDemo;import java.awt.*;import java.awt.event.*;import javax.swing.*;import java.util.Vector;public class Calculator {  String str1 = "0"; // 运算数1 初值一定为0 为了程序的安全  String str2 = "0"; // 运算数2  String signal = "+"; // 运算符  String result = "";// 结果  // 状态开关  int k1 = 1;// 开关1 用于选择输入方向 将要写入str2或 str2  int k2 = 1;// 开关2 符号键 次数 k2>1说明进行的是2+3-9+8 这样的多符号运算  int k3 = 1;// 开关3 str1 是否可以被清0 ==1时可以 !=1时不能被清0  int k4 = 1;// 开关4 str2 同上  int k5 = 1;// 开关5 控制小数点可否被录入 ==1时可以 !=1 输入的小数点被丢掉  JButton store; // 寄存器 记录 是否连续按下符号键  @SuppressWarnings("rawtypes")  Vector vt = new Vector(20, 10);  JFrame frame = new JFrame("VeVb武林网 - 计算器");  JTextField result_TextField = new JTextField(result, 20);// 20列  JButton clear_Button = new JButton("清除");  JButton button0 = new JButton("0");  JButton button1 = new JButton("1");  JButton button2 = new JButton("2");  JButton button3 = new JButton("3");  JButton button4 = new JButton("4");  JButton button5 = new JButton("5");  JButton button6 = new JButton("6");  JButton button7 = new JButton("7");  JButton button8 = new JButton("8");  JButton button9 = new JButton("9");  JButton button_Dian = new JButton(".");  JButton button_jia = new JButton("+");  JButton button_jian = new JButton("-");  JButton button_cheng = new JButton("*");  JButton button_chu = new JButton("/");  JButton button_dy = new JButton("=");  Calculator() {    button0.setMnemonic(KeyEvent.VK_0);// 等效键    // 其它 等效键 略,    result_TextField.setHorizontalAlignment(JTextField.RIGHT);// 文本框 右对齐    JPanel pan = new JPanel();    pan.setLayout(new GridLayout(4, 4, 5, 5));// 四行四列 边距为5像素    pan.add(button7);    pan.add(button8);    pan.add(button9);    pan.add(button_chu);    pan.add(button4);    pan.add(button5);    pan.add(button6);    pan.add(button_cheng);    pan.add(button1);    pan.add(button2);    pan.add(button3);    pan.add(button_jian);    pan.add(button0);    pan.add(button_Dian);    pan.add(button_dy);    pan.add(button_jia);    pan.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));// pan对象的边距    JPanel pan2 = new JPanel();    pan2.setLayout(new BorderLayout());    pan2.add(result_TextField, BorderLayout.WEST);    pan2.add(clear_Button, BorderLayout.EAST);    frame.setLocation(300, 200); // 主窗口 出现在位置    frame.setResizable(false); // 不能调大小    frame.getContentPane().setLayout(new BorderLayout());    frame.getContentPane().add(pan2, BorderLayout.NORTH);    frame.getContentPane().add(pan, BorderLayout.CENTER);    frame.pack();    frame.setVisible(true);    // 事件处理 程 序    // 数 字 键    class Listener implements ActionListener {      @SuppressWarnings("unchecked")      public void actionPerformed(ActionEvent e) {        String ss = ((JButton) e.getSource()).getText();        store = (JButton) e.getSource();        vt.add(store);        if (k1 == 1) {          if (k3 == 1) {            str1 = "";            k5 = 1;// 还原开关k5状态          }          str1 = str1 + ss;          k3 = k3 + 1;          result_TextField.setText(str1);// 显示        } else if (k1 == 2) {          if (k4 == 1) {            str2 = "";            k5 = 1; // 还原开关k5状态          }          str2 = str2 + ss;          k4 = k4 + 1;          result_TextField.setText(str2);        }      }    }    // 符 号    class Listener_signal implements ActionListener {      @SuppressWarnings("unchecked")      public void actionPerformed(ActionEvent e) {        String ss2 = ((JButton) e.getSource()).getText();        store = (JButton) e.getSource();        vt.add(store);        if (k2 == 1) {          k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写          k5 = 1;          signal = ss2;          k2 = k2 + 1;// 按符号键的次数        } else {          int a = vt.size();          JButton c = (JButton) vt.get(a - 2);          if (!(c.getText().equals("+"))              && !(c.getText().equals("-"))              && !(c.getText().equals("*"))              && !(c.getText().equals("/")))          {            cal();            str1 = result;            k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写            k5 = 1;            k4 = 1;            signal = ss2;          }          k2 = k2 + 1;        }      }    }    // 清除    class Listener_clear implements ActionListener {      @SuppressWarnings("unchecked")      public void actionPerformed(ActionEvent e) {        store = (JButton) e.getSource();        vt.add(store);        k5 = 1;        k2 = 1;        k1 = 1;        k3 = 1;        k4 = 1;        str1 = "0";        str2 = "0";        signal = "";        result = "";        result_TextField.setText(result);        vt.clear();      }    }    // 等 于    class Listener_dy implements ActionListener {      @SuppressWarnings("unchecked")      public void actionPerformed(ActionEvent e) {        store = (JButton) e.getSource();        vt.add(store);        cal();        k1 = 1; // 还原开关k1状态        // str1=result;        k2 = 1;        k3 = 1;// 还原开关k3状态        k4 = 1; // 还原开关k4状态        str1 = result; // 为7+5=12 +5=17 这种计算做准备      }    }    // 小数点    class Listener_xiaos implements ActionListener {      @SuppressWarnings("unchecked")      public void actionPerformed(ActionEvent e) {        store = (JButton) e.getSource();        vt.add(store);        if (k5 == 1) {          String ss2 = ((JButton) e.getSource()).getText();          if (k1 == 1) {            if (k3 == 1) {              str1 = "";              k5 = 1; // 还原开关k5状态            }            str1 = str1 + ss2;            k3 = k3 + 1;            result_TextField.setText(str1);// 显示          } else if (k1 == 2) {            if (k4 == 1) {              str2 = "";              k5 = 1; // 还原开关k5状态            }            str2 = str2 + ss2;            k4 = k4 + 1;            result_TextField.setText(str2);          }        }        k5 = k5 + 1;      }    }    // 注册 监听器    Listener_dy jt_dy = new Listener_dy();    Listener jt = new Listener();// 临听数字键    Listener_signal jt_signal = new Listener_signal();// 临 听符 号键    Listener_clear jt_c = new Listener_clear(); // 清除键    Listener_xiaos jt_xs = new Listener_xiaos();// 小数点 键    button7.addActionListener(jt);    button8.addActionListener(jt);    button9.addActionListener(jt);    button_chu.addActionListener(jt_signal);    button4.addActionListener(jt);    button5.addActionListener(jt);    button6.addActionListener(jt);    button_cheng.addActionListener(jt_signal);    button1.addActionListener(jt);    button2.addActionListener(jt);    button3.addActionListener(jt);    button_jian.addActionListener(jt_signal);    button0.addActionListener(jt);    button_Dian.addActionListener(jt_xs);    button_dy.addActionListener(jt_dy);    button_jia.addActionListener(jt_signal);    clear_Button.addActionListener(jt_c);    // 关闭事件处理程序    frame.addWindowListener(new WindowAdapter() {      public void windowClosing(WindowEvent e) {        System.exit(0);      }    });  }  // 计 算  public void cal() {    double a2;// 运算数1    double b2;// 运算数2    String c = signal;// 运算符    double result2 = 0;// 结果    if (c.equals("")) {      result_TextField.setText("请输入运算符");    } else {      if (str1.equals(".")) // 字符串 "." 转换成double型数据时 会出错 所以手工转        str1 = "0.0";      if (str2.equals("."))        str2 = "0.0";      a2 = Double.valueOf(str1).doubleValue();      b2 = Double.valueOf(str2).doubleValue();      if (c.equals("+")) {        result2 = a2 + b2;      }      if (c.equals("-")) {        result2 = a2 - b2;      }      if (c.equals("*")) {        result2 = a2 * b2;      }      if (c.equals("/")) {        if (b2 == 0) {          result2 = 0;        } else {          result2 = a2 / b2;        }      }      result = ((new Double(result2)).toString());      result_TextField.setText(result);    }  }  @SuppressWarnings("unused")  public static void main(String[] args) {    // 界面风格，可以去除  try {          UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");    } catch (Exception e) {      e.printStackTrace();    }    Calculator cal = new Calculator();  }}