基于windows的简单计算器

学习java时写的一个基于windows的简单计算器
BuildBtn.java

import java.awt.Color;
import java.awt.Font;
import java.awt.Insets;
import java.awt.event.ActionListener;

import javax.swing.JButton;
/**
 * 构造有监听器和颜色的按钮
 */
public class BuildBtn extends JButton {
	
	private String btnName;
	private ActionListener listener;
	private Color color;
	
	public BuildBtn()
	{
	}
	
	public BuildBtn(String btnName, ActionListener listener, Color color) {
		super();
		this.setFont(new Font("宋体",0,12));
		this.setMargin(new Insets(0,0,0,0));
		this.setText(btnName);
		this.addActionListener(listener);
		this.setForeground(color);
	}
	public String getBtnName() {
		return btnName;
	}
	public void setBtnName(String btnName) {
		this.btnName = btnName;
	}
	public ActionListener getListener() {
		return listener;
	}
	public void setListener(ActionListener listener) {
		this.listener = listener;
	}
	public Color getColor() {
		return color;
	}
	public void setColor(Color color) {
		this.color = color;
	}
	

}

Calculator.java

package com.demo;

import java.awt.Color;
import java.awt.GridLayout;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import com.sun.java.swing.plaf.windows.*;
/**
 * 计算器面板布局
 */
public class Calculator extends JFrame {
	
	private JButton b[];
	private JButton dotbtn,addbtn,subbtn,mulbtn,divbtn,backspace,
	       c,equalbtn,ce,mc,mr,ms,mm,dif,sqrt,percent,rec;
	private GridLayout gl1,gl2,gl3;
	private JTextField txtinput,mText;
	private JPanel p0,p1,p2,p3;
	private String showStr = "";//显示条显示的数字
	private Integer flag = 0;   //标志位
	private Double operatorX = 0d,operatorY = 0d; //操作数
	private Double result;   //操作结果
	private Boolean boperator = false;//判断是否是在点击运算符
	private Boolean bre = false;     //是否第一次按下操作数
	private Integer nIndex = 0;     //记录当前的操作数个数
	private static Double m = 0d; //记忆数字
	private Boolean isValue = false;//第二个操作数是否有值
	private Boolean isoperator = false;
	
	public Calculator() throws HeadlessException {
//		try {
//			UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
//		} catch (ClassNotFoundException e1) {
//			// TODO Auto-generated catch block
//			e1.printStackTrace();
//		} catch (InstantiationException e1) {
//			// TODO Auto-generated catch block
//			e1.printStackTrace();
//		} catch (IllegalAccessException e1) {
//			// TODO Auto-generated catch block
//			e1.printStackTrace();
//		} catch (UnsupportedLookAndFeelException e1) {
//			// TODO Auto-generated catch block
//			e1.printStackTrace();
//		}
		//设置Windows风格
		try {
			UIManager.setLookAndFeel(new WindowsLookAndFeel());
		} catch (UnsupportedLookAndFeelException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
		BtnListener btnListener = new BtnListener();
		b = new BuildBtn[10];
		for(int i = 0;i < 10;i++)
		{
			b[i] = new BuildBtn("" + i + "",btnListener,Color.blue);
		}
		// 声明三个面板的布局
		gl1 = new GridLayout(1,3,5,0);
		gl2 = new GridLayout(5,1,0,5);
		gl3 = new GridLayout(4,5,5,5);
		
		p0 = new JPanel();
		p1 = new JPanel();
		p2 = new JPanel();
		p3 = new JPanel();

		// 显示条
		txtinput = new JTextField(36);
		txtinput.setEditable(false);
		txtinput.setBackground(Color.white);
		txtinput.setHorizontalAlignment(JTextField.RIGHT);
		txtinput.setText("0.");

		p0.add(txtinput);
		p0.setBounds(0, 20, 248, 25);
		this.add(p0);

		// 实例化按钮并添加面板p2中的组件和设置其在框架中的位置和大小
		this.setLayout(null);
		mText = new JTextField();
		
		mText.setEditable(false);
		mText.setBorder(BorderFactory.createLoweredBevelBorder());
		mc = new BuildBtn("MC",btnListener,Color.red);
		mr = new BuildBtn("MR",btnListener,Color.red);
		ms = new BuildBtn("MS",btnListener,Color.red);
		mm = new BuildBtn("M+",btnListener,Color.red);
		p2.setLayout(gl2);
		p2.add(mText);
		p2.add(mc);
		p2.add(mr);
		p2.add(ms);
		p2.add(mm);
		//p2.setBackground(Color.red);
		p2.setBounds(10, 55, 30, 150);
		this.add(p2);
		
		// 实例化按钮并添加面板p1中的组件和设置其在框架中的位置和大小
		backspace = new BuildBtn("Backspace",btnListener,Color.red);
		ce = new BuildBtn("CE",btnListener,Color.red);
		c = new BuildBtn("C",btnListener,Color.red);
		p1.setLayout(gl1);
		//p1.setBackground(Color.red);
		p1.add(backspace);
		p1.add(ce);
		p1.add(c);
		p1.setBounds(48, 55, 190, 25);
		this.add(p1);

		// 实例化按钮并添加面板p3中的组件和设置其在框架中的位置和大小
		dotbtn = new BuildBtn(".",btnListener,Color.blue);
		addbtn = new BuildBtn("+",btnListener,Color.red);
		subbtn = new BuildBtn("-",btnListener,Color.red);
		mulbtn = new BuildBtn("*",btnListener,Color.red);
		divbtn = new BuildBtn("/",btnListener,Color.red);
		dif = new BuildBtn("+/-",btnListener,Color.blue);
		sqrt = new BuildBtn("sqrt",btnListener,Color.blue);
		percent = new BuildBtn("%",btnListener,Color.blue);
		rec = new BuildBtn("1/x",btnListener,Color.blue);
		equalbtn = new BuildBtn("=",btnListener,Color.red);
		p3.setLayout(gl3);
		//p3.setBackground(Color.green);
		p3.add(b[7]);
		p3.add(b[8]);
		p3.add(b[9]);
		p3.add(divbtn);
		p3.add(sqrt);
		
		p3.add(b[4]);
		p3.add(b[5]);
		p3.add(b[6]);
		p3.add(mulbtn);
		p3.add(percent);
		
		p3.add(b[1]);
		p3.add(b[2]);
		p3.add(b[3]);
		p3.add(subbtn);
		p3.add(rec);
		
		p3.add(b[0]);
		p3.add(dif);
		p3.add(dotbtn);
		p3.add(addbtn);
		p3.add(equalbtn);

		p3.setBounds(48, 85, 190, 120);
		this.add(p3);
	
		

		// 关闭窗口   
		addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		
		this.setTitle("计算器");
		this.setResizable(false);
		this.setBackground(Color.darkGray);
		this.setBounds(50, 50, 255, 245);
		this.setVisible(true);
	}
	
	
	public class BtnListener implements ActionListener {
		public void init()
		{
			showStr = "";
			operatorX = 0d;
			operatorY = 0d;
			flag = 0;
			result = 0d;
			nIndex = 0;
			isValue = false;
			bre = false;
			txtinput.setText("0.");
		}

		public void actionPerformed(ActionEvent e) {
			if(e.getSource() == ce)// 选择"CE"清零
			{
				this.init();
			}else if(e.getSource() == c)// 选择"C"清零
			{
				this.init();
				
			}else if(e.getSource() == backspace)//退格
			{
				if(txtinput.getText().equals("0."));
				else if(txtinput.getText().length() == 1)
				{
					showStr = "";
					txtinput.setText("0.");
				}
				else if(!boperator)
				{
					showStr = showStr.substring(0, showStr.length() - 1);
					txtinput.setText(showStr);
					//txtinput.setText(txtinput.getText().substring(0, txtinput.getText().length() - 1));
				}
			}else if(e.getSource() == mc)//清除记忆数字
			{
				bre = false;
				showStr = "";
				m = 0d;
				mText.setText("");
			}else if(e.getSource() == mr)//提起记忆数字
			{
				showStr = "";
				if(m == 0)
					txtinput.setText("0.");
				else
				{
					txtinput.setText(m.toString());
					if(flag == 0)
					{
						nIndex++;
						if(nIndex > 2)nIndex = 2;
						operatorX = m;
					}
					else
					{
						nIndex++;
						if(nIndex > 2)nIndex = 2;
						isValue = true;
						operatorY = m;
					}
				}
			}else if(e.getSource() == ms)//存取记忆数字
			{
				if(Double.parseDouble(txtinput.getText()) == 0);
				else
				{
					showStr = "";
					m = Double.parseDouble(txtinput.getText());
					mText.setText("M");
				}
				   
			}else if(e.getSource() == mm)//当前数字加上存取的记忆数作为新记忆数
			{
				showStr = "";
				m += Double.parseDouble(txtinput.getText());
			}else if(e.getSource() == b[0])//当输入0的时候
			{
				if(showStr.length() == 0);
				else
				{
					showStr = txtinput.getText() + e.getActionCommand().toString();
					txtinput.setText(showStr);
					if(nIndex == 1)
						operatorX = Double.parseDouble(showStr);
					if(nIndex == 2)
						operatorY = Double.parseDouble(showStr);
				}				
			}else if(e.getSource() == dotbtn)//点击小数点的时候
			{
				if(showStr.contains("."));
				else
				{
					if(bre)nIndex++;
					if(showStr.length() == 0)
						showStr += "0";
					showStr += e.getActionCommand().toString();
					txtinput.setText(showStr);
					if(nIndex == 1)
						operatorX = Double.parseDouble(showStr);
					if(nIndex == 2)
						operatorY = Double.parseDouble(showStr);
				}	
			}else if(e.getSource() == dif)//改变符号
			{
				if(txtinput.getText().equals("0."));
				else 
				{
					Double temp = Double.parseDouble(txtinput.getText());
					temp = -temp;
					showStr = temp.toString();
					txtinput.setText(showStr);
					if(nIndex == 1)
						operatorX = Double.parseDouble(showStr);
					if(nIndex == 2)
						operatorY = Double.parseDouble(showStr);
				}		
			}else if(e.getSource() == addbtn)//点击加号
			{
				operatorNumber(bre,nIndex,flag);
				bre = true;
				flag = 1;
				
			}else if(e.getSource() == subbtn)//点击减号
			{
				operatorNumber(bre,nIndex,flag);
				bre = true;
				flag = 2;
				
			}else if(e.getSource() == mulbtn)//点击乘号
			{
				operatorNumber(bre,nIndex,flag);
				bre = true;
				flag = 3;
				
			}else if(e.getSource() == divbtn)//点击除号
			{
				operatorNumber(bre,nIndex,flag);
				bre = true;
				flag = 4;
				
			}else if(e.getSource() == sqrt)//开根号
			{
				boperator = true;
				flag = 0;
				if(Double.parseDouble(txtinput.getText()) < 0)
					txtinput.setText("函数输入无效.");
				else if(nIndex == 1)
				{
					operatorX = Math.sqrt(operatorX);
					showStr = operatorX.toString();
					txtinput.setText(showStr);
					showStr = "";
				}
				else if(nIndex == 2)
				{
					operatorY = Math.sqrt(operatorY);	
					showStr = operatorY.toString();
					txtinput.setText(showStr);
					showStr = "";
				}
			}else if(e.getSource() == percent)//点击%号
			{
				boperator = true;
				flag = 0;
				if(nIndex < 2 && flag == 0)
				{
					this.init();
				}
				else
				{
					operatorX = operatorX*operatorY/100.0;	
					showStr = operatorX.toString();
					txtinput.setText(showStr);
					showStr = "";
				}
			}
			else if(e.getSource() == rec)//点击求倒数
			{
				boperator = true;
				flag = 0;
				if(Double.parseDouble(txtinput.getText()) == 0)
					txtinput.setText("除数不能为0.");
				if(nIndex == 1)
				{
					operatorX = 1.0/operatorX;;
					showStr = operatorX.toString();
					txtinput.setText(showStr);
					showStr = "";
				}
				if(nIndex == 2)
				{
					operatorY = 1.0/operatorY;;		
					showStr = operatorY.toString();
					txtinput.setText(showStr);
					showStr = "";
				}
			}else if(e.getSource() == equalbtn)//点击等号
			{			
				operatorEqual(bre,nIndex,flag);
			}
			else
			{
				boperator = false;
				showStr += e.getActionCommand().toString();
				txtinput.setText(showStr);
				if(bre&&flag != 0)
				{
					if(!isoperator)
					{
						operatorY = Double.parseDouble(txtinput.getText().trim());
						isValue = true;
						nIndex++;
						if(nIndex > 2)nIndex = 2;
					}
				}
				else//初始化第一个操作数
				{
					operatorX = Double.parseDouble(txtinput.getText().trim());
					operatorY = Double.parseDouble(txtinput.getText().trim());  //默认两个操作数是一样的
					nIndex++;
					if(nIndex > 2)nIndex = 2;
				}
			}
			
		}
	}
	
	/**
	 * 加减乘除运算
	 * @param bre 是否第一次按下操作数
	 * @param nIndex 操作数个数
	 * @param flag 标志位
	 */
	public void operatorNumber(Boolean bre,Integer nIndex,Integer flag)
	{
		isoperator = false;
		boperator = true;
		if(bre&&nIndex == 2)
		{
			switch(flag)
			{
			case 1:
				operatorX += operatorY;
				showStr = operatorX.toString();
				txtinput.setText(showStr);
				break;
			case 2:
				operatorX -= operatorY;
				showStr = operatorX.toString();
				txtinput.setText(showStr);
				break;
			case 3:
				operatorX *= operatorY;
				showStr = operatorX.toString();
				txtinput.setText(showStr);
				break;
			case 4:
				if(operatorY == 0)
					txtinput.setText("除数不能为0.");
				else
				{
					operatorX /= operatorY;
					showStr = operatorX.toString();
					txtinput.setText(showStr);
				}
				break;
			}
		}
		result = operatorX;
		showStr = "";
		this.nIndex = 1;
	}
	/**
	 * =号运算
	 * @param bre 是否第一次按下操作数
	 * @param nIndex 操作数个数
	 * @param flag 标志位
	 */
	public void operatorEqual(Boolean bre,Integer nIndex,Integer flag)
	{
		boperator = true;
		if(bre&&nIndex == 1)//操作连加
		{
			if(isValue)operatorX = operatorY;
			switch(flag)
			{
			case 1:
				result += operatorX;
				showStr = result.toString();;
				txtinput.setText(showStr);
				break;
			case 2:
				result -= operatorX;
				showStr = result.toString();;
				txtinput.setText(showStr);
				break;
			case 3:
				result *= operatorX;
				showStr = result.toString();;
				txtinput.setText(showStr);
				break;
			case 4:
				if(operatorY == 0)
					txtinput.setText("除数不能为0.");
				else
				{
					result /= operatorX;
					showStr = result.toString();;
					txtinput.setText(showStr);
				}
				break;
			}
			showStr = "";
			this.nIndex = 1;
		}
		if(bre&&nIndex == 2)//普通情况的求等
		{
			switch(flag)
			{
			case 1:
				result = operatorX + operatorY;
				showStr = result.toString();
				txtinput.setText(showStr);
				break;
			case 2:
				result = operatorX - operatorY;
				showStr = result.toString();;
				txtinput.setText(showStr);
				break;
			case 3:
				result = operatorX*operatorY;
				showStr = result.toString();;
				txtinput.setText(showStr);
				break;
			case 4:
				if(operatorY == 0)
					txtinput.setText("除数不能为0.");
				else
				{
					result = operatorX/operatorY;
					showStr = result.toString();;
					txtinput.setText(showStr);
				}
				break;
			}
			//operatorX = operatorY;
			showStr = "";
			this.nIndex = 1;
		}
		isoperator = true;
		showStr = "";
		operatorX = result;
		bre = true;
	}
	

}

test.java

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		new Calculator();

	}

}