Swing实现的简易计算器

学习了Swing基础中的基础知识，做了个简易中的简易版计算器，囧……

在退格按钮的事件处理代码块中还存在异常，不过不影响计算，纯属练习，呃,不多说了，上代码

 

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;

public class CounterTest {

 private JFrame frame;
 private JPanel panel;
 private JTextField textfile;
 private StringBuffer sb = new StringBuffer("");
 private StringBuffer sb1 = new StringBuffer("");   //用来暂时存储第一个数字的数据
 private StringBuffer sb2 = new StringBuffer("");   ////用来暂时存储第二个数字的数据
 private String countMethod = "";  //用来接收计算方法的字符串
 private Double num1;              //用来接收第一个数字
 private Double num2;              //用来接收第二个数字
 private double result = 0;        //用来接收计算结果
 
 public CounterTest(){
  frame = new JFrame("LHY版简易计算器");
  panel = new JPanel();
  textfile = new JTextField();
  frame.setBounds(20, 20, 400, 630);
  frame.setResizable(false);
  frame.setVisible(true);
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  createPanel();
  createNumBar();
 }
 
 /**
  * 创建计算器面板
  */
 public void createPanel(){
  frame.add(panel);
  panel.setLayout(null);
  panel.setBounds(20,20,400, 630);
  
  JButton btnNull = new JButton("欢迎使用");
  btnNull.setBounds(0, 100, 100, 100);
  panel.add(btnNull);
  
  //退格按钮
  JButton btnBack = new JButton("退格");
  btnBack.setBounds(100, 100, 100, 100);
  panel.add(btnBack);
  btnBack.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    Character judge = sb.toString().charAt(sb.length()-1);
    try{
     sb = sb.deleteCharAt(sb.length()-1);
     String str = sb.toString();
     textfile.setText(str);
     
     if((judge.equals("+") || judge.equals("-") || judge.equals("*") || judge.equals("/")) == true){
      countMethod = "";
      return;
     }else if(countMethod.length() != 0){
       sb2 = sb2.deleteCharAt(sb2.length()-1);
       String str2 = sb2.toString();
       num2 = Double.parseDouble(str2);
     }else if(countMethod.length() == 0){
      sb1 = sb1.deleteCharAt(sb1.length()-1);
      String str1 = sb1.toString();
      num1 = Double.parseDouble(str1);
     }
     
     ///////////////////////////////////////////////////////
//     if(countMethod.length() == 0){
//      sb1 = sb1.deleteCharAt(sb1.length()-1);
//      String str1 = sb1.toString();
//      num1 = Double.parseDouble(str1);
//     }else if(countMethod.length() != 0){
//      if(judge.equals("+") || judge.equals("-") || judge.equals("*") || judge.equals("/")){
//       countMethod = "";
//      }else{
//       sb2 = sb2.deleteCharAt(sb2.length()-1);
//       String str2 = sb2.toString();
//       num2 = Double.parseDouble(str2);
//      }
//     }
     ////////////////////////////////////////////////////////
     
    }catch(Exception ex){
     ex.printStackTrace();
    }
   }
  });
  
  //CE按钮
  JButton btnCE = new JButton("CE(清零)");
  btnCE.setBounds(200, 100, 100, 100);
  panel.add(btnCE);
  btnCE.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    createNumBar();
    sb = new StringBuffer("");
    sb1 = new StringBuffer("");
    sb2 = new StringBuffer("");
    countMethod = "";
   }
  });
  
  //C按钮
  JButton btnC = new JButton("C");
  btnC.setBounds(300, 100, 100, 100);
  panel.add(btnC);
  
  //数字7按钮
  JButton btn7 = new JButton("7");
  btn7.setBounds(0, 200, 100, 100);
  panel.add(btn7);
  btn7.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    
    sb.append("7");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("7");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("7");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字8按钮
  JButton btn8 = new JButton("8");
  btn8.setBounds(100, 200, 100, 100);
  panel.add(btn8);
  btn8.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("8");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("8");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("8");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字9按钮
  JButton btn9 = new JButton("9");
  btn9.setBounds(200, 200, 100, 100);
  panel.add(btn9);
  btn9.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("9");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("9");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("9");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //除号按钮
  JButton btnDivision = new JButton("/");
  btnDivision.setBounds(300, 200, 100, 100);
  panel.add(btnDivision);
  btnDivision.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    countMethod = "/";
    sb.append("/");
    String str = sb.toString();
    textfile.setText(str);
   }
  });
  
  //数字4按钮
  JButton btn4 = new JButton("4");
  btn4.setBounds(0, 300, 100, 100);
  panel.add(btn4);
  btn4.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("4");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("4");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("4");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字5按钮
  JButton btn5 = new JButton("5");
  btn5.setBounds(100, 300, 100, 100);
  panel.add(btn5);
  btn5.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("5");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("5");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("5");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字6按钮
  JButton btn6 = new JButton("6");
  btn6.setBounds(200, 300, 100, 100);
  panel.add(btn6);
  btn6.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("6");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("6");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("6");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //乘号按钮
  JButton btnMult = new JButton("*");
  btnMult.setBounds(300, 300, 100, 100);
  panel.add(btnMult);
  btnMult.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    countMethod = "*";
    sb.append("*");
    String str = sb.toString();
    textfile.setText(str);
   }
  });
  
  //数字1按钮
  JButton btn1 = new JButton("1");
  btn1.setBounds(0, 400, 100, 100);
  panel.add(btn1);
  btn1.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("1");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("1");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("1");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字2按钮
  JButton btn2 = new JButton("2");
  btn2.setBounds(100, 400, 100, 100);
  panel.add(btn2);
  btn2.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("2");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("2");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("2");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //数字3按钮
  JButton btn3 = new JButton("3");
  btn3.setBounds(200, 400, 100, 100);
  panel.add(btn3);
  btn3.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("3");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("3");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("3");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //减号按钮
  JButton btnSub = new JButton("-");
  btnSub.setBounds(300, 400, 100, 100);
  panel.add(btnSub);
  btnSub.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    countMethod = "-";
    sb.append("-");
    String str = sb.toString();
    textfile.setText(str);
   }
  });
  
  //数字0按钮
  JButton btn0 = new JButton("0");
  btn0.setBounds(0, 500, 100, 100);
  panel.add(btn0);
  btn0.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append("0");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append("0");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append("0");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //小数点按钮
  JButton btnDot = new JButton(".");
  btnDot.setBounds(100, 500, 100, 100);
  panel.add(btnDot);
  btnDot.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    sb.append(".");
    String str = sb.toString();
    textfile.setText(str);
    
    if(countMethod.length() == 0){
     sb1.append(".");
     num1 = Double.parseDouble(sb1.toString());
    }else if(countMethod.length() != 0){
     sb2.append(".");
     num2 = Double.parseDouble(sb2.toString());
    }
   }
  });
  
  //等号按钮
  JButton btnEqual = new JButton("=");
  btnEqual.setBounds(200, 500, 100, 100);
  panel.add(btnEqual);
  btnEqual.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    countNum();
   }
  });
  
  //加号按钮
  JButton btnAdd = new JButton("+");
  btnAdd.setBounds(300, 500, 100, 100);
  panel.add(btnAdd);
  btnAdd.addActionListener(new ActionListener() {
   
   @Override
   public void actionPerformed(ActionEvent e) {
    countMethod = "+";
    sb.append("+");
    String str = sb.toString();
    textfile.setText(str);
   }
  });
 }
 
 /**
  * 创建计算器显示条
  */
 public void createNumBar(){
  textfile.setText("");
  textfile.setBounds(0, 0, 400, 100);
  panel.add(textfile);
 }
 
 /**
  * 进行计算的方法
  */
 public void countNum(){
  if(countMethod.equals("+")){
   addMethod();
  }else if(countMethod.equals("-")){
   subMethod();
  }else if(countMethod.equals("*")){
   multMethod();
  }else if(countMethod.equals("/")){
   divisionMethod();
  }else{
   ///////////////////////////////////////
  }
 }
 
 /**
  * 加法
  */
 public void addMethod(){
  result = num1 + num2;
  sb.append("=").append(result);
  String str = sb.toString();
  textfile.setText(str);
 }
 
 /**
  * 减法
  */
 public void subMethod(){
  result = num1 - num2;
  sb.append("=").append(result);
  String str = sb.toString();
  textfile.setText(str);
 }
 
 /**
  * 乘法
  */
 public void multMethod(){
  result = num1 * num2;
  sb.append("=").append(result);
  String str = sb.toString();
  textfile.setText(str);
 }
 
 /**
  * 除法
  */
 public void divisionMethod(){
  result = num1 / num2;
  sb.append("=").append(result);
  String str = sb.toString();
  textfile.setText(str);
 }
 
 public static void main(String[] args) {
  
  new CounterTest();
 }

}