Java---计算器（标准计算器，科学计算器）的实现

Java-计算器（标准计算器和科学计算器）的实现可以先建两个类，一个是Biaozhun 用来实现标准计算器，另一个是Kexue 用来实现科学计算器通过功能菜单实现科学计算器和标准计算器的转换具体代码中，在Biaozhun类和 Kexue类各自定义相对应的事件来实现转换menuItem_1.addActionListener(new ActionListener()menuItem....

via CHEng

19689人浏览 · 2019-05-22 14:18:31

via CHEng · 2019-05-22 14:18:31 发布

Java-计算器（标准计算器和科学计算器）的实现
/ 需要说明这里的文本框中并不能呈现出算数表达式，有时间改进
可以先建两个类，一个是Biaozhun 用来实现标准计算器，另一个是Kexue 用来实现科学计算器

通过功能菜单实现科学计算器和标准计算器的转换

具体代码中，在Biaozhun类和 Kexue类各自定义相对应的事件来实现转换

menuItem_1.addActionListener(new ActionListener()
menuItem.addActionListener(new ActionListener()

对于每一个按钮也要设置相应的事件响应（详情见代码）

代码部分

首先是标准计算器的实现

package dazuoye;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
@SuppressWarnings("serial")
public class Biaozhun extends JFrame implements ActionListener {
	private final String[] KEYS = { "*", "/", "7", "8", "9","+", "4", "5", "6", "-", "1", "2", "3", "|x|","0",".","=", "1/x" };
	private final String[] COMMAND = { "Back", "C" };
	private JButton keys[] = new JButton[KEYS.length];
	private JButton commands[] = new JButton[COMMAND.length];
	private JTextField resultText = new JTextField("0");
	private boolean firstDigit = true;
	private double resultNum = 0.0;
	private String operator = "=";
	private boolean operateValidFlag = true;
	StringBuffer sb = new StringBuffer();
	String vl = null;
	public Biaozhun() {
		setTitle("标准型");
		this.setBackground(Color.LIGHT_GRAY);
		this.setTitle("标准计算器");
		this.setLocation(500, 300);
		this.setSize(500, 500);
		this.setResizable(false);
		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
		JMenu menu = new JMenu("功能");
		menuBar.add(menu);
		JMenuItem menuItem = new JMenuItem("标准型");
		menu.add(menuItem);
		JMenuItem menuItem_1 = new JMenuItem("科学型");
		menu.add(menuItem_1);
		menuItem_1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				Kexue science = new Kexue();
				science.setVisible(true);
				}
			}
		);
		resultText.setHorizontalAlignment(JTextField.RIGHT);
		resultText.setBackground(Color.white);
		resultText.setFont(new Font("TimesRoman",Font.BOLD,46));
		JPanel PPanel = new JPanel();
		PPanel.setLayout(new GridLayout(5, 4, 3, 3));
		for (int i = 0; i < COMMAND.length; i++) {
			commands[i] = new JButton(COMMAND[i]);
			PPanel.add(commands[i]);
			commands[i].setFont(new Font("Courir",Font.PLAIN,20));
		}
		for (int i = 0; i < KEYS.length; i++) {
			keys[i] = new JButton(KEYS[i]);
			PPanel.add(keys[i]);
			keys[i].setFont(new Font("Courir",Font.ITALIC,20));
		}
		JPanel panel1 = new JPanel();
		panel1.setLayout(new BorderLayout(3,3));
		panel1.add("Center", PPanel);
		JPanel top = new JPanel();
		top.setLayout(new BorderLayout());
		top.add("Center", resultText);
		
		getContentPane().setLayout(new BorderLayout(3, 5));
		getContentPane().add("North", top);
		getContentPane().add("Center", panel1);
		for (int i = 0; i < KEYS.length; i++) {
			keys[i].addActionListener(this);
		}
		for (int i = 0; i < COMMAND.length; i++) {
			commands[i].addActionListener(this);
		}
	}
	
	public void actionPerformed(ActionEvent e) {
		String label = e.getActionCommand();
		if (label.equals(COMMAND[0])) {
			handleBack();
		} 
		else if (label.equals(COMMAND[1])) {
			handleC();
		} 
		else if ("0123456789.".indexOf(label) >= 0) {
			handleNumber(label);
		} 
		else
			handleOperator(label);
	}
	
	private void handleBack() {
		String text = resultText.getText();
		int i = text.length();
		if (i > 0) {
			text = text.substring(0, i - 1);
			if (text.length() == 0) {
				resultText.setText("0");
				firstDigit = true;
				operator = "=";
			}
			else
				resultText.setText(text);
		}
	}

	private void handleNumber(String key) {
		if (firstDigit) {
			resultText.setText(key);
		}
		else if ((key.equals(".")) && (resultText.getText().indexOf(".") < 0)) {
			resultText.setText(resultText.getText() + ".");
		}
		else if (!key.equals(".")) {
			resultText.setText(resultText.getText() + key);
		}
		firstDigit = false;
	}
	
	private void handleC() {
		resultText.setText("0");
		firstDigit = true;
		operator = "=";
	}
	
	private void handleOperator(String key) {
		if (operator.equals("/")) {
			if (getNumberFromText() == 0.0) {
				operateValidFlag = false;
				resultText.setText("除数不能为零");
			}
			else 
				resultNum /= getNumberFromText();
		} 
		else if (operator.equals("1/x")) {
			if (resultNum == 0.0) {
				operateValidFlag = false;
				resultText.setText("零没有倒数");
			}
			else
				resultNum = 1 / resultNum;
			}
		else if (operator.equals("+")) {
			resultNum += getNumberFromText();
		}
		else if (operator.equals("-")) {
			resultNum -= getNumberFromText();
		}
		else if (operator.equals("*")) {
			resultNum *= getNumberFromText();
		}
		else if (operator.equals("|x|")) {
			resultNum = Math.abs(resultNum);
		}
		else if (operator.equals("=")) {
			resultNum = getNumberFromText();
		}
		if (operateValidFlag) {
			long t1;
			double t2;
			t1 = (long) resultNum;
			t2 = resultNum - t1;
			if (t2 == 0) {
				resultText.setText(String.valueOf(t1));
			}
			else {
				resultText.setText(String.valueOf(resultNum));
			}
		}
		operator = key;
		firstDigit = true;
		operateValidFlag = true;
	}

	private double getNumberFromText() {
		double result = 0;
		try {
			result = Double.valueOf(resultText.getText()).doubleValue();
		} catch (NumberFormatException e) {}
		return result;
	}
	
	public static void main(String args[]) {
		Biaozhun application = new Biaozhun();
		application.setVisible(true);
		application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
}

接着是科学计算器的实现

package dazuoye;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
@SuppressWarnings("serial")
public class Kexue extends JFrame implements ActionListener {
	private final String[] KEYS = { "*", "/", "7", "8", "9","+", "4", "5", "6", "-", "1", "2", "3", "|x|","0",".","=", "1/x" };
	private final String[] COMMAND = { "Back", "C" };
	private JButton keys[] = new JButton[KEYS.length];
	private JButton commands[] = new JButton[COMMAND.length];
	private JTextField resultText = new JTextField("0");

	private boolean firstDigit = true;
	private double resultNum = 0.0;
	private String operator = "=";
	private boolean operateValidFlag = true;
	private final String[] KEYS2= {"X^2","X^3","X^Y","Sqrt","rt","X!","ln","lg","%","sin","cos","tan","PI","e","e^X"};
	private JButton keys2[]=new JButton[KEYS2.length];
	StringBuffer sb = new StringBuffer();
	String vl = null;
	private JPanel contentPane,contentpane2;

	private FlowLayout layout;
	
	public Kexue()
	{
		super("科学型");
		this.setBackground(Color.LIGHT_GRAY);
		this.setTitle("科学计算器");
		this.setSize(800, 500);
		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
		JMenu menu = new JMenu("功能");
		menuBar.add(menu);
		JMenuItem menuItem = new JMenuItem("标准型");
		menu.add(menuItem);
		JMenuItem menuItem_1 = new JMenuItem("科学型");
		menu.add(menuItem_1);
		menuItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				Biaozhun ordinary = new Biaozhun();
				ordinary.setVisible(true);
				}
			}
		);
		
		resultText.setHorizontalAlignment(JTextField.RIGHT);
		resultText.setBackground(Color.white);
		resultText.setFont(new Font("TimesRoman",Font.BOLD,46));
		
		JPanel PPanel=new JPanel();
		PPanel.setLayout(new GridLayout(5, 4, 3, 3));
		for (int i = 0; i < COMMAND.length; i++) {
			commands[i] = new JButton(COMMAND[i]);
			PPanel.add(commands[i]);
			commands[i].setFont(new Font("Courir",Font.PLAIN,20));
		}
		for (int i = 0; i < KEYS.length; i++) {
			keys[i] = new JButton(KEYS[i]);
			PPanel.add(keys[i]);
			keys[i].setFont(new Font("Courir",Font.ITALIC,20));
		}
		JPanel panel1 = new JPanel();
		panel1.setLayout(new BorderLayout(3,3));
		panel1.add("Center", PPanel);
		JPanel top = new JPanel();
		top.setLayout(new BorderLayout());
		top.add("Center", resultText);
		contentPane=new JPanel();
		contentPane.setLayout(new BorderLayout(3, 5));
		contentPane.add("North", top);
		contentPane.add("Center", panel1);
		
		
//second
		JPanel ppanel=new JPanel();
		ppanel.setLayout(new GridLayout(5, 3, 3, 3));
		for (int i = 0; i < KEYS2.length; i++) {
			keys2[i] = new JButton(KEYS2[i]);
			ppanel.add(keys2[i]);
			keys2[i].setFont(new Font("Courir",Font.ITALIC,20));
		}
		contentpane2 = new JPanel();
		contentpane2.setLayout(new BorderLayout(3, 5));
		contentpane2.add("Center", ppanel);
		
		layout=new FlowLayout();
		JPanel ane= new JPanel();
		ane.setLayout(layout);
		getContentPane().setLayout(new BorderLayout(3,5));
		getContentPane().add("Center", contentPane);
		getContentPane().add("East", contentpane2);
//event
		for (int i = 0; i < KEYS.length; i++) {
			keys[i].addActionListener(this);
		}
		for (int i = 0; i < COMMAND.length; i++) {
			commands[i].addActionListener(this);
		}
		for (int i = 0; i < KEYS2.length; i++)
			keys2[i].addActionListener(this);
		setVisible(true);
	}
//make it
		public void actionPerformed(ActionEvent e)
		{
			String label = e.getActionCommand();
			if (label.equals(COMMAND[0])) {
				handleBack();
			} 
			else if (label.equals(COMMAND[1])) {
				handleC();
			} 
			else if ("0123456789.".indexOf(label) >= 0) {
				handleNumber(label);
			}
			else if(label.equals("PI"))
				resultText.setText(String.valueOf(3.14159265));
			else if(label.equals("e"))
				resultText.setText(String.valueOf(2.17828));
			else
				handleOperator(label);
		}
		
		//
		private void handleBack() {
			String text = resultText.getText();
			int i = text.length();
			if (i > 0) {
				text = text.substring(0, i - 1);
				if (text.length() == 0) {
					resultText.setText("0");
					firstDigit = true;
					operator = "=";
				}
				else
					resultText.setText(text);
			}
		}

		private void handleNumber(String key) {
			if (firstDigit) {
				resultText.setText(key);
			}
			else if ((key.equals(".")) && (resultText.getText().indexOf(".") < 0)) {
				resultText.setText(resultText.getText() + ".");
			}
			else if (!key.equals(".")) {
				resultText.setText(resultText.getText() + key);
			}
			firstDigit = false;
		}
		
		private void handleC() {
			resultText.setText("0");
			firstDigit = true;
			operator = "=";
		}
		
		private void handleOperator(String key) {
			if (operator.equals("/")) {
				if (getNumberFromText() == 0.0) {
					operateValidFlag = false;
					resultText.setText("除数不能为零");
				}
				else 
					resultNum /= getNumberFromText();
			} 
			else if (operator.equals("1/x")) {
				if (resultNum == 0.0) {
					operateValidFlag = false;
					resultText.setText("零没有倒数");
				}
				else
					resultNum = 1 / resultNum;
				}
			else if (operator.equals("+")) {
				resultNum += getNumberFromText();
			}
			else if (operator.equals("-")) {
				resultNum -= getNumberFromText();
			}
			else if (operator.equals("*")) {
				resultNum *= getNumberFromText();
			}
			else if (operator.equals("|x|")) {
				resultNum = Math.abs(resultNum);
			}
			else if (operator.equals("X^2")) {
				resultNum = resultNum*resultNum;
			}
			else if (operator.equals("X^3")) {
				resultNum = resultNum*resultNum*resultNum;
			}
			else if (operator.equals("X^Y")) {
				resultNum = Math.pow(resultNum,getNumberFromText());
			}
			else if (operator.equals("Sqrt")) {
				resultNum = Math.sqrt(resultNum);
			}
			else if (operator.equals("rt")) {
				resultNum = resultNum*57.3;
			}
			else if (operator.equals("X!")) {
				int ee;
				double re=resultNum ;
				int c=1;
				for(ee=1;ee<=re;ee++)
				{
					c=c*ee;
					resultNum=c;}
			}
			else if (operator.equals("ln")) {
				resultNum = Math.log(resultNum);
			}
			else if (operator.equals("lg")) {
				resultNum = Math.log10(resultNum);
			}
			else if (operator.equals("%")) {
				resultNum %= getNumberFromText();
			}else if (operator.equals("sin")) {
				resultNum = Math.sin(resultNum);
			}
			else if (operator.equals("cos")) {
				resultNum = Math.cos(resultNum);
			}
			else if (operator.equals("tan")) {
				resultNum = Math.tan(resultNum);
			}
			else if (operator.equals("e^X")) {
				resultNum = Math.exp(resultNum);
			}
			else if (operator.equals("=")) {
				resultNum = getNumberFromText();
			}
			if (operateValidFlag) {
				long t1;
				double t2;
				t1 = (long) resultNum;
				t2 = resultNum - t1;
				if (t2 == 0) {
					resultText.setText(String.valueOf(t1));
				}
				else {
					resultText.setText(String.valueOf(resultNum));
				}
			}
			operator = key;
			firstDigit = true;
			operateValidFlag = true;
		}

		private double getNumberFromText() {
			double result = 0;
			try {
				result = Double.valueOf(resultText.getText()).doubleValue();
			} catch (NumberFormatException e) {}
			return result;
		}
		
		public static void main(String args[]) {
			EventQueue.invokeLater(new Runnable() {
				public void run() {
					try {
						Kexue application = new Kexue();
						application.setVisible(true);
						
						} catch (Exception e) {
							e.printStackTrace();
							}
					}
				}
			);
		}
		
}