calculator.java

一个 简单的java 编写的绘图程序

package Calculator;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

public class Calculator extends JFrame {
  JPanel contentPane;
  BorderLayout borderLayout1 = new BorderLayout();
//实例化控件

  private JTextField txtNumber = new JTextField();
                private JTextField txt = new JTextField();

                private JButton jb0 = new JButton("0");
                private JButton jb1 = new JButton("1");
                private JButton jb2 = new JButton("2");
                private JButton jb3 = new JButton("3");
                private JButton jb4 = new JButton("4");
                private JButton jb5 = new JButton("5");
                private JButton jb6 = new JButton("6");
                private JButton jb7 = new JButton("7");
                private JButton jb8 = new JButton("8");
                private JButton jb9 = new JButton("9");

                private JButton jbsum = new JButton("+");
                private JButton jbdec = new JButton("-");
                private JButton jbride = new JButton("*");
                private JButton jbrem = new JButton("/");

                private JButton jbsqrt = new JButton("sqrt");
                private JButton jbfshu = new JButton("1/x");
                private JButton jbbfen = new JButton("%");
                private JButton jbamount = new JButton("=");

                private JButton jbZorF = new JButton("+/-");
                private JButton jbdian = new JButton(".");

                private JButton jbmc = new JButton("MC");
                private JButton jbmr = new JButton("MR");
                private JButton jbms = new JButton("MS");
                private JButton jbmjia = new JButton("M+");

                private JButton jbbackspace = new JButton("Backspace");
                private JButton jbce = new JButton("CE");
                private JButton jbc = new JButton("C");

                private double tmp;
                private int op;

                private boolean bool;


  //Construct the frame
  public Calculator() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception  {
    contentPane = (JPanel) this.getContentPane();
    contentPane.setLayout(borderLayout1);
    this.setSize(new Dimension(400, 300));
    this.setTitle("计算器");
    txtNumber.setHorizontalAlignment(txtNumber.RIGHT);

                txt.setBackground(Color.lightGray);
                txt.disable();

                //设置数据面板
                JPanel pNumber = new JPanel(new GridLayout(4,5));
                pNumber.add(jb7);
                pNumber.add(jb8);
                pNumber.add(jb9);
                pNumber.add(jbrem);
                pNumber.add(jbsqrt);

                pNumber.add(jb4);
                pNumber.add(jb5);
                pNumber.add(jb6);
                pNumber.add(jbride);

    pNumber.add(jbbfen, null);
    pNumber.add(jb1);
    pNumber.add(jb2);
                pNumber.add(jb3);
                pNumber.add(jbdec);
                pNumber.add(jbfshu);

                pNumber.add(jbZorF);
    pNumber.add(jb0);
                pNumber.add(jbdian);
                pNumber.add(jbsum);
                pNumber.add(jbamount);

		pNumber.setBorder(new EtchedBorder());
 //               pNumber.setBorder(new LineBorder(Color.BLUE));

                //设置清除面板
                JPanel pClear = new JPanel(new GridLayout(1,4));
                pClear.add(txt);
        pClear.add(jbbackspace);
        pClear.add(jbce);
                pClear.add(jbc);
                pClear.setBorder(new LineBorder(Color.BLUE));

                //设置存储面板
                JPanel pMemory = new JPanel(new GridLayout(4,1));
                pMemory.add(jbmc);
                pMemory.add(jbmr);
                pMemory.add(jbms);
                pMemory.add(jbmjia);
                pMemory.setBorder(new LineBorder(Color.BLUE));

                //设置综合面板
                JPanel p = new JPanel(new BorderLayout());
                p.add(pClear,BorderLayout.NORTH);
                p.add(pMemory,BorderLayout.WEST);
                p.add(pNumber,BorderLayout.CENTER);
                p.setBorder(new EtchedBorder());
                JPanel ptxt = new JPanel(new BorderLayout());
                ptxt.add(txtNumber,BorderLayout.CENTER);
                ptxt.setBorder(new LineBorder(Color.BLUE));

                Container c = this.getContentPane();
                c.setLayout(new BorderLayout());
                c.add(ptxt,BorderLayout.NORTH);
                c.add(p,BorderLayout.CENTER);

                //设置窗体
                int width=350,height=250;
                this.setSize(width,height);
                Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
                this.setLocation((d.width-width)/2,(d.height-height)/2);
                this.setResizable(false);
                this.setVisible(true);
                this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                //为按纽事件添加监听

                //数字按纽，使用内部类  NumberListener;
                jb0.addActionListener(new NumberListener());
                jb1.addActionListener(new NumberListener());
                jb2.addActionListener(new NumberListener());
                jb3.addActionListener(new NumberListener());
                jb4.addActionListener(new NumberListener());
                jb5.addActionListener(new NumberListener());
                jb6.addActionListener(new NumberListener());
                jb7.addActionListener(new NumberListener());
                jb8.addActionListener(new NumberListener());
                jb9.addActionListener(new NumberListener());

                //运算按纽，使用内部类  OperationListener;
                jbsum.addActionListener(new OperationListener());
                jbdec.addActionListener(new OperationListener());
                jbride.addActionListener(new OperationListener());
                jbrem.addActionListener(new OperationListener());
                jbamount.addActionListener(new OperationListener());
                jbsqrt.addActionListener(new OperationListener());
                jbfshu.addActionListener(new OperationListener());


                //正负号按纽
                jbZorF.addActionListener(new ActionListener(){
                        public void actionPerformed(ActionEvent e){

                                if(txtNumber.getText().indexOf("-") == -1){
                                        txtNumber.setText("-" + txtNumber.getText());
                                }else{
                                        int i = txtNumber.getText().length();
                                        txtNumber.setText(txtNumber.getText().substring(1,i));
                                }
                        }
                });

                //小数点按纽
                jbdian.addActionListener(new ActionListener(){
                        public void actionPerformed(ActionEvent e){
                                if(bool){
                                        txtNumber.setText("0.");
                                        bool = false;
                                }
                                if(txtNumber.getText().indexOf(".") == -1){
                                        txtNumber.setText(txtNumber.getText() + ".");
                                }
                        }
                });

                //
                //清除按纽


                jbc.addActionListener(new ActionListener(){

                        public void actionPerformed(ActionEvent e){
                                txtNumber.setText("");
                                tmp = 0;
                                op = 0;
                                bool = false;

                        }
                });

                jbce.addActionListener(new ActionListener(){

                        public void actionPerformed(ActionEvent e){
                                txtNumber.setText("");
                        }

                });

                jbbackspace.addActionListener(new ActionListener(){

                        public void actionPerformed(ActionEvent e){
                                int i = txtNumber.getText().length();
                                txtNumber.setText(txtNumber.getText().substring(0,i-1));

                        }
                });

                //存储按纽





  }
  //内部类，NumberListener 为数字监听类，用于数字按纽的监听
        private class NumberListener implements ActionListener{
                public void actionPerformed(ActionEvent e){

                        if(bool){
                                txtNumber.setText("");
                                bool=false;
                        }
                        txtNumber.setText(txtNumber.getText() + e.getActionCommand());

                }
        }

        //内部类，OperationListener 为运算按纽监听类，用于对四则运算按纽的监听
        private class OperationListener implements ActionListener{
                double res;
                void result(){
                        double tmpend = Double.parseDouble(txtNumber.getText());

                        switch (op){
                                case 1:
                                        res = tmp + tmpend;
                                        break;

                                case 2:
                                        res = tmp - tmpend;
                                        break;

                                case 3:
                                        res = tmp * tmpend;
                                        break;

                                case 4:
                                        try{
                                                res = tmp / tmpend;
                                        }catch(Exception ex){
                                                        txtNumber.setText("除数不能为零");
                                        }
                                        break;
                        }
                        txtNumber.setText(new Double(res).toString());
                        tmp = 0;
                        op = 0;

                }
                public void actionPerformed(ActionEvent e){

                        String str=e.getActionCommand();

                        char s=str.charAt(0);

                        if (op!=0){
                                result();
                        }

                        bool=true;

                        switch (s){
                                case '+':
                                        tmp = Double.parseDouble(txtNumber.getText());
                                        op = 1;
                                        break;

                                case '-':
                                        tmp = Double.parseDouble(txtNumber.getText());
                                        op = 2;
                                        break;

                                case '*':
                                        tmp = Double.parseDouble(txtNumber.getText());
                                        op = 3;
                                        break;

                                case '/':
                                        tmp = Double.parseDouble(txtNumber.getText());
                                        op=4;
                                        break;

                                case '=':
                                        result();
                                        break;
                        }

                        if ("sqrt" == str){
                                res = Math.sqrt(Double.parseDouble(txtNumber.getText()));
                                txtNumber.setText(new Double(res).toString());
                        }

                        if ("1/x" == str){
                                tmp = Double.parseDouble(txtNumber.getText());
                                if (tmp != 0){
                                        res = 1 / tmp;
                                        txtNumber.setText(new Double(res).toString());
                                }else{
                                        txtNumber.setText("除数不能为零");
                                }
                        }
                }
        }

  //Overridden so we can exit when window is closed
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }
  public static void main(String[] args){
  	new Calculator();	
  }
}