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主题：求教高手小程序问题

200618222 [专家分：0] 发布于 2008-12-13 13:09:00

最近老师留个JAVA小计算器。。完成+  -  *   /   的功能要求可以键盘输入~~以下是我自己编写的一个程序。。但就是实现不了用键盘也可一实现输入0--9，且用小键盘进行运算~~~请高手给改改。。。最后说明我哪做错了。。。。越明白越好。。本人很菜谢谢！！！

import java.awt.*;
import java.lang.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.text.DecimalFormat;
public class Calculator
    implements ActionListener { //导入动作监听接口
  //设计面板中的单位
  JFrame frame;
  JTextField textAnswer;
  JPanel panel, panel1, panel2, panel3;
  JMenuBar mainMenu;
  JTextField textMemory;
  JLabel labelMemSpace; //labelMemSpace单纯做摆设，控制面板的形状
  JButton buttonBk, buttonC;
  JButton button[];
  JButton  buttonMR, buttonMS;
  JButton buttonDot, buttonAdd, buttonSub, buttonMul,
      buttonDiv;
  JButton  buttonEqual;
  DecimalFormat df; //设置数据输出精度
  boolean clickable; //控制当前能否按键
  double memoryd; //使用内存中存储的数字
  int memoryi;
  double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd)
  short key = -1, prekey = -1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算
  String copy; //做复制用

  //构造函数
  public Calculator() {
    clickable = true;
    answerd = 0;
    JFrame frame = new JFrame("欢迎使用吕景先的计算器");
    df = new DecimalFormat("0.##############"); //设置数据输出精度(对于double型值)
    textAnswer = new JTextField(15);
    textAnswer.setText("");
    textAnswer.setEditable(false);
    textAnswer.setBackground(new Color(255, 255, 255));
    panel = new JPanel();
    frame.getContentPane().add(panel);
    panel1 = new JPanel();
    panel2 = new JPanel();
    panel.setLayout(new BorderLayout());
    //设计整个面板
    mainMenu = new JMenuBar();

    panel.add(mainMenu, BorderLayout.NORTH);
    panel.add(textAnswer, BorderLayout.CENTER);
    panel.add(panel1, BorderLayout.SOUTH);
    panel1.setLayout(new BorderLayout());
    textMemory = new JTextField(3);
    textMemory.setEditable(false);
    textMemory.setBackground(new Color(217, 217, 217));
    labelMemSpace = new JLabel("                   ");
    buttonBk = new JButton("退格(←)");
    buttonBk.setForeground(new Color(255, 0, 0));
    buttonC = new JButton("清除(Q)");
    buttonC.setForeground(new Color(255, 0, 0));
    buttonBk.addActionListener(this);
    buttonC.addActionListener(this);
    panel1.add(panel2, BorderLayout.NORTH);
    panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
    panel2.add(textMemory);
    panel2.add(labelMemSpace);
    panel2.add(buttonBk);
    panel2.add(buttonC);

    panel3 = new JPanel();
    panel1.add(panel3, BorderLayout.CENTER);
    button = new JButton[10];
    panel3.setLayout(new GridLayout(5,3));
    for (int i = 0; i < button.length; i++) {
      button = new JButton(Integer.toString(i));
      button.setForeground(new Color(0, 0, 255));
    }
    buttonMR = new JButton("显示（X）");
    buttonMR.setForeground(new Color(255, 0, 0));
    buttonMS = new JButton("记忆（j）");
    buttonMS.setForeground(new Color(255, 0, 0));
    buttonDot = new JButton(".");
    buttonDot.setForeground(new Color(0, 0, 255));
    buttonAdd = new JButton("+");
    buttonAdd.setForeground(new Color(255, 0, 0));
    buttonSub = new JButton("-");
    buttonSub.setForeground(new Color(255, 0, 0));
    buttonMul = new JButton("*");
    buttonMul.setForeground(new Color(255, 0, 0));
    buttonDiv = new JButton("/");
    buttonDiv.setForeground(new Color(255, 0, 0));
    buttonEqual = new JButton("=");
    buttonEqual.setForeground(new Color(255, 0, 0));
    //将所有行为与监听绑定
    panel3.add(button[7]);
    button[7].addActionListener(this);
    panel3.add(button[8]);
    button[8].addActionListener(this);
    panel3.add(button[9]);
    button[9].addActionListener(this);
    panel3.add(buttonDiv);
    buttonDiv.addActionListener(this);
    panel2.add(buttonMR);
    buttonMR.addActionListener(this);
    panel3.add(button[4]);
    button[4].addActionListener(this);
    panel3.add(button[5]);
    button[5].addActionListener(this);
    panel3.add(button[6]);
    button[6].addActionListener(this);
    panel3.add(buttonMul);
    buttonMul.addActionListener(this);
    panel2.add(buttonMS);
    buttonMS.addActionListener(this);
    panel3.add(button[1]);
    button[1].addActionListener(this);
    panel3.add(button[2]);
    button[2].addActionListener(this);
    panel3.add(button[3]);
    button[3].addActionListener(this);
    panel3.add(buttonSub);
    buttonSub.addActionListener(this);
    panel3.add(button[0]);
    button[0].addActionListener(this);
    panel3.add(buttonDot);
    buttonDot.addActionListener(this);
    panel3.add(buttonAdd);
    buttonAdd.addActionListener(this);
    panel3.add(buttonEqual);
    buttonEqual.addActionListener(this);


    frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
    frame.pack();
    frame.show();
  }
  //设置各个按钮行为
  public void actionPerformed(ActionEvent event) {

    Object temp = event.getSource();
    try {
      //如果按下数据按钮，将按下的按钮代表的数据插入的当前文本框字符串之后
      for (int i = 0; i <= 9; i++)
        if (temp == button && clickable == true)
          textAnswer.setText(textAnswer.getText() + Integer.toString(i));
          //按下'.'按钮时，判断当前文本框内字符串中含不含'.'，如果已含，则不允许再插入'.'
      if (temp == buttonDot && clickable == true) {
        boolean isDot = false;
        if (textAnswer.getText().length() == 0)
          isDot = true;
        for (int i = 0; i < textAnswer.getText().length(); i++)
          if ('.' == textAnswer.getText().charAt(i)) {
            isDot = true;
            break;
          }
        if (isDot == false)
          textAnswer.setText(textAnswer.getText() + ".");
      }
      if ( (temp == buttonAdd || temp == buttonSub || temp == buttonMul ||
            temp == buttonDiv) && clickable == true) {
        //'+'操作
        if (temp == buttonAdd) {
          switch (prekey) {
            case 0:
              answerd += Double.parseDouble(textAnswer.getText());
              break;
            case 1:
              answerd -= Double.parseDouble(textAnswer.getText());
              break;
            case 2:
              answerd *= Double.parseDouble(textAnswer.getText());
              break;
            case 3:
              if (Double.parseDouble(textAnswer.getText()) == 0) {
                textAnswer.setText("除数不能为零");
                clickable = false;
              }
              else
                answerd /= Double.parseDouble(textAnswer.getText());
              break;
            default:
              answerd = Double.parseDouble(textAnswer.getText());
          }
          textAnswer.setText("");
          prekey = key = 0;
        }
        //'-'操作
        if (temp == buttonSub) {
          switch (prekey) {
            case 0:
              answerd += Double.parseDouble(textAnswer.getText());
              break;
            case 1:
              answerd -= Double.parseDouble(textAnswer.getText());
              break;
            case 2:
              answerd *= Double.parseDouble(textAnswer.getText());
              break;
            case 3:
              if (Double.parseDouble(textAnswer.getText()) == 0) {
                textAnswer.setText("除数不能为零");
                clickable = false;
              }
              else
                answerd /= Double.parseDouble(textAnswer.getText());
              break;
            default:
              answerd = Double.parseDouble(textAnswer.getText());
          }
          textAnswer.setText("");
          prekey = key = 1;
        }

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沙发

200618222 [专家分：0] 发布于 2008-12-13 13:11:00

//'*'操作
        if (temp == buttonMul) {
          switch (prekey) {
            case 0:
              answerd += Double.parseDouble(textAnswer.getText());
              break;
            case 1:
              answerd -= Double.parseDouble(textAnswer.getText());
              break;
            case 2:
              answerd *= Double.parseDouble(textAnswer.getText());
              break;
            case 3:
              if (Double.parseDouble(textAnswer.getText()) == 0) {
                textAnswer.setText("除数不能为零");
                clickable = false;
              }
              else
                answerd /= Double.parseDouble(textAnswer.getText());
              break;
            default:
              answerd = Double.parseDouble(textAnswer.getText());
          }
          textAnswer.setText("");
          prekey = key = 2;
        }
        //'/'操作
        if (temp == buttonDiv) {
          switch (prekey) {
            case 0:
              answerd += Double.parseDouble(textAnswer.getText());
              break;
            case 1:
              answerd -= Double.parseDouble(textAnswer.getText());
              break;
            case 2:
              answerd *= Double.parseDouble(textAnswer.getText());
              break;
            case 3:
              if (Double.parseDouble(textAnswer.getText()) == 0) {
                textAnswer.setText("除数不能为零");
                clickable = false;
              }
              else
                answerd /= Double.parseDouble(textAnswer.getText());
              break;
            default:
              answerd = Double.parseDouble(textAnswer.getText());
          }
          textAnswer.setText("");
          prekey = key = 3;
        }
      }
      //'='操作
      if (temp == buttonEqual && clickable == true) {
        //如果连续按'=',则进行连续运算
        if (prekey == 5) {
          if (key == 0) {
            answerd += vard;
            textAnswer.setText(df.format(answerd));
          }
          if (key == 1) {
            answerd -= vard;
            textAnswer.setText(df.format(answerd));
          }
          if (key == 2) {
            answerd *= vard;
            textAnswer.setText(df.format(answerd));
          }
          if (key == 3) {
            if (Double.parseDouble(textAnswer.getText()) == 0) {
              textAnswer.setText("除数不能为零");
              clickable = false;
            }
            else {
              answerd /= vard;
              textAnswer.setText(df.format(answerd));
            }
          }
        }
        else {
          vard = Double.parseDouble(textAnswer.getText());
          if (key == 0) {
            prekey = -1;
            answerd += Double.parseDouble(textAnswer.getText());
            textAnswer.setText(df.format(answerd));
          }
          if (key == 1) {
            prekey = -1;
            answerd -= Double.parseDouble(textAnswer.getText());
            textAnswer.setText(df.format(answerd));
          }
          if (key == 2) {
            prekey = -1;
            answerd *= Double.parseDouble(textAnswer.getText());
            textAnswer.setText(df.format(answerd));
          }
          if (key == 3) {
            prekey = -1;
            if (Double.parseDouble(textAnswer.getText()) == 0) {
              textAnswer.setText("除数不能为零");
              clickable = false;
            }
            else {
              answerd /= Double.parseDouble(textAnswer.getText());
              textAnswer.setText(df.format(answerd));
            }
          }
        }
        prekey = 5;
      }

      //计算器有关内存操作

      //'MS'的操作，将当前文本框内容保存入内存，显示'M'
      if (temp == buttonMS && clickable == true) {
        boolean isDot = false;
        textMemory.setText("   M");
        for (int i = 0; i < textAnswer.getText().length(); i++)
          if ('.' == textAnswer.getText().charAt(i)) {
            isDot = true;
            break;
          }
        //如果是double,则存入memoryd(double存储器)
        if (isDot == true) {
          memoryd = Double.parseDouble(textAnswer.getText());
          memoryi = 0; //保证存储器中存放最新的值
        }
        //如果是int,则存入memoryi(int存储器)
        else {
          memoryi = Integer.parseInt(textAnswer.getText());
          memoryd = 0; //保证存储器中存放最新的值
        }
      }
      //'MR'的操作，将存储器中的信息输出
      if (temp == buttonMR && clickable == true) {
        if (memoryd != 0)
          textAnswer.setText(Double.toString(memoryd));
        if (memoryi != 0)
          textAnswer.setText(Integer.toString(memoryi));
      }

      //按下'Backspace'键，利用循环将当前字符串中的最后一个字母删除
      if (temp == buttonBk && clickable == true) {
        String s = textAnswer.getText();
        textAnswer.setText("");
        for (int i = 0; i < s.length() - 1; i++) {
          char a = s.charAt(i);
          textAnswer.setText(textAnswer.getText() + a);
        }
      }
      //按下'C'按钮，文本框内数据清除，同时var,answer清0
      if (temp == buttonC) {
        vard = answerd = 0;
        textAnswer.setText("");
        clickable = true;
      }

    }
    //输入中如果有操作非法，比如按下两次'+'，捕获异常
    catch (Exception e) {
      textAnswer.setText("操作非法");
      clickable = false;
    }
}
class KeyPanel extends JPanel
implements KeyListener
{
public KeyPanel()
{
  //注册监听器
      panel3.add(button[7]);
    button[7].addKeyListener(this);
    panel3.add(button[8]);
    button[8].addKeyListener(this);
    panel3.add(button[9]);
    button[9].addKeyListener(this);
    panel3.add(buttonDiv);
    buttonDiv.addKeyListener(this);
    panel2.add(buttonMR);
    buttonMR.addKeyListener(this);
    panel3.add(button[4]);
    button[4].addKeyListener(this);
    panel3.add(button[5]);
    button[5].addKeyListener(this);
    panel3.add(button[6]);
    button[6].addKeyListener(this);
    panel3.add(buttonMul);
    buttonMul.addKeyListener(this);
    panel2.add(buttonMS);
    buttonMS.addKeyListener(this);
    panel3.add(button[1]);
    button[1].addKeyListener(this);
    panel3.add(button[2]);
    button[2].addKeyListener(this);
    panel3.add(button[3]);
    button[3].addKeyListener(this);
    panel3.add(buttonSub);
    buttonSub.addKeyListener(this);
    panel3.add(button[0]);
    button[0].addKeyListener(this);
    panel3.add(buttonDot);
    buttonDot.addKeyListener(this);
    panel3.add(buttonAdd);
    buttonAdd.addKeyListener(this);
    panel3.add(buttonEqual);
    buttonEqual.addKeyListener(this);
}
public boolean isFocusTraversable()
{
  //允许面板获得焦点
  return true;
}
public void keyPressed(KeyEvent ke)
{
  //得到虚拟键码

}
public void keyReleased(KeyEvent ke) {
System.out.println(ke.getKeyChar());
// 从键盘读入数字
if (ke.getKeyChar() == '0') {
button[0].doClick();
}
if (ke.getKeyChar() == '1') {
button[1].doClick();
}
if (ke.getKeyChar() == '2') {
button[2].doClick();
}
if (ke.getKeyChar() == '3') {
button[3].doClick();
}
if (ke.getKeyChar() == '4') {
button[4].doClick();
}
if (ke.getKeyChar() == '5') {
button[5].doClick();
}
if (ke.getKeyChar() == '6') {
button[6].doClick();
}
if (ke.getKeyChar() == '7') {
button[7].doClick();
}
if (ke.getKeyChar() == '8') {
button[8].doClick();
}
if (ke.getKeyChar() == '9') {
button[9].doClick();
}
// 从键盘输入小数点
if (ke.getKeyChar() == '.')
buttonDot.doClick();
// 加法
if (ke.getKeyChar() == '+') {
buttonAdd.doClick();
}
// 减法
if (ke.getKeyChar() == '-') {
buttonSub.doClick();
}
// 乘法
if (ke.getKeyChar() == '*') {
buttonMul.doClick();
}
// 除法
if (ke.getKeyChar() == '/') {
buttonDiv.doClick();
}
if (ke.getKeyChar() == '=') {
buttonEqual.doClick();
}
if (ke.getKeyChar() == 'T') {
buttonBk.doClick();
}
if (ke.getKeyChar() == 'Q') {
buttonC.doClick();
}
}
public void keyTyped(KeyEvent ke) {
}
    }
  //主函数
  public static void main(String args[]) {
    new Calculator();
  }
}

板凳

lupj [专家分：10] 发布于 2008-12-14 00:49:00

temp == button && clickable == true 改为 temp == button[i] && clickable == true
Object temp = event.getSource();
temp只是其中一个button[i]对象
不要KeyPanel这个内部类了 ,让Calculator实现KeyListener接口

将keyReleased内的代码移到 keyPressed 中 ,别忘了把KeyPanel() 的代码加到Calculator()中

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