java简易计算器

只简单的说一下设计的思路

1.整个计算机的组件我分为三个部分，数字按键0-9， 符号按键+-*/= ，结果框resultField

2.变量解释说明

private String numList = "0123456789";

定义字符串包含所有的数字，因为对于数字按键的监听操作都是差不多的，通过获取数字按键的值在通过与numList的对比，就能确定数字按键的类型
private static int operation = 1; //record pervious operation,"+"——1(default)  "-"——2

符号标记值  记录上一次符号按键的值 1表示+ 2表示- 3表示*  4表示/

private static int result = 0;//record the result that stored currently

用来记录当前操作的最终结果值

private static int num_opera = 1;//if the pervious operation is pressing number,num_opera is 1,else if it is config operation, num_opera is 2
用来记录上一次的用户操作是数字按键还是符号按键

import java.awt.BorderLayout;import java.awt.Color;import java.awt.Dimension;import java.awt.GridLayout;import java.awt.TextField;import java.awt.Toolkit;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JOptionPane;import javax.swing.JPanel;/** *  * @author zero * */public class Calculator extends JFrame{private String numList = "0123456789";private static int operation = 1; //record pervious operation,"+"——1(default)  "-"——2    private static int result = 0;//record the result that stored currently    private static int num_opera = 1;//if the pervious operation is pressing number,num_opera is 1,else if it is config operation, num_opera is 2    private static TextField resultField;    public Calculator() {this.setTitle("简易计算器");this.setLocation(20, 20);setSizeAndCentralizeMe(320, 380);this.addWindowListener(new WindowAdapter() {@Overridepublic void windowOpened(WindowEvent e) {JOptionPane.showConfirmDialog(null, "Welcome to my litter calculator", "Welcome", JOptionPane.PLAIN_MESSAGE); super.windowOpened(e);}@Overridepublic void windowClosing(WindowEvent e) {JOptionPane.showConfirmDialog(null, "Thank you for your using...", "ByeBye", JOptionPane.PLAIN_MESSAGE); super.windowClosing(e);System.exit(0);}});}public void generateCalculator(Calculator calculator) {calculator.setLayout(new BorderLayout());JPanel mainPanel = new JPanel(new GridLayout(5, 3, 5, 5));JPanel panel = new JPanel(new GridLayout(1, 2, 3, 5));calculator.setBackground(Color.blue);for(int i=0; i<15; i++){ if(i<9) {JButton button = new JButton(String.valueOf(i+1));button.addMouseListener(buttonListener);mainPanel.add(button);}else {JButton button = new JButton();switch(i) {case 9 : {button.setText("-"); break;}case 10 : {button.setText("0"); break;}case 11 : {button.setText("+"); break;}case 12 : {button.setText("*"); break;}case 13 : {button.setText("C"); break;}case 14 : {button.setText("/"); break;}}if(!button.getText().equals("C")) {button.addMouseListener(buttonListener);}else {button.addMouseListener(cButtonListener);}mainPanel.add(button);}}JButton button = new JButton("=");button.addMouseListener(buttonListener);resultField = new TextField();panel.add(button);panel.add(resultField);panel.setVisible(true);mainPanel.setVisible(true);calculator.getContentPane().add("Center", mainPanel);calculator.getContentPane().add("South", panel);calculator.setVisible(true);}private void setSizeAndCentralizeMe(int width, int height) {Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();this.setSize(width, height);this.setLocation(screenSize.width / 2 - width / 2, screenSize.height/ 2 - height / 2);}private MouseListener cButtonListener = new MouseAdapter() {@Overridepublic void mouseClicked(MouseEvent e) {  operation = 1;      result = 0;      num_opera = 1;      resultField.setText("0");}};private  MouseListener buttonListener = new MouseAdapter() {@Overridepublic void mouseClicked(MouseEvent e) {String text = ((JButton)e.getSource()).getText();if(numList.contains(text)) {int number = Integer.valueOf(text); if (num_opera == 1) { String newtext = resultField.getText() + text; resultField.setText(newtext);     }else if (num_opera == 2) {     resultField.setText(text);         num_opera = 1;     }}else {if (num_opera == 1) {            if (operation == 1) {                result = result + Integer.valueOf(resultField.getText());                resultField.setText(String.valueOf(result));            }            else if (operation == 2)  {             result = result - Integer.valueOf(resultField.getText());             resultField.setText(String.valueOf(result));            }            else if (operation == 3)  {             result = result * Integer.valueOf(resultField.getText());             resultField.setText(String.valueOf(result));            }            else if (operation == 4)  {             result = result / Integer.valueOf(resultField.getText());              resultField.setText(String.valueOf(result));            }        }           switch(text) { case "+" : {operation = 1;break;}case "-" : {operation = 2;break;}case "*" : {operation = 3;break;}case "/" : {operation = 4;break;}case "=" : {operation = 1;break;}}num_opera = 2;}}};public static void main(String[] args) {Calculator calculator = new Calculator();calculator.generateCalculator(calculator);}}