java計算器程序

⑴ 求一個java計算器程序

正方形的，實現數字加、減、乘、除四則運算。

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.text.DecimalFormat;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator {
private JFrame f = new JFrame("Calculator");
private JPanel inputPanel = new JPanel();
private JPanel operationPanel = new JPanel();
private JPanel buttonsPanel = new JPanel();

private JTextField input = new JTextField(20);

private JButton backspace = new JButton("BackSpace");
private JButton CE = new JButton("CE ");
private JButton C = new JButton("C ");

private JButton add = new JButton("+");
private JButton sub = new JButton("-");
private JButton mul = new JButton("*");
private JButton div = new JButton("/");

private JButton decimal = new JButton(".");
private JButton equal = new JButton("=");

private JButton zero = new JButton("0");
private JButton one = new JButton("1");
private JButton two = new JButton("2");
private JButton three = new JButton("3");
private JButton four = new JButton("4");
private JButton five = new JButton("5");
private JButton six = new JButton("6");
private JButton seven = new JButton("7");
private JButton eight = new JButton("8");
private JButton nine = new JButton("9");

private String num1 = "";
private String operator = "";

public static void main(String[] args) {
new Calculator();
}

public Calculator(){
inputPanel.add(input);
f.add(inputPanel, BorderLayout.NORTH);

operationPanel.add(backspace);
operationPanel.add(CE);
operationPanel.add(C);
f.add(operationPanel, BorderLayout.CENTER);

buttonsPanel.add(add);
buttonsPanel.add(sub);
buttonsPanel.add(mul);
buttonsPanel.add(div);
buttonsPanel.add(one);
buttonsPanel.add(two);
buttonsPanel.add(three);
buttonsPanel.add(zero);
buttonsPanel.add(four);
buttonsPanel.add(five);
buttonsPanel.add(six);
buttonsPanel.add(decimal);
buttonsPanel.add(seven);
buttonsPanel.add(eight);
buttonsPanel.add(nine);
buttonsPanel.add(equal);
buttonsPanel.setLayout(new GridLayout(4, 4));
f.add(buttonsPanel, BorderLayout.SOUTH);

backspace.addMouseListener(new OperationMouseListener());
CE.addMouseListener(new OperationMouseListener());
C.addMouseListener(new OperationMouseListener());
decimal.addMouseListener(new OperationMouseListener());
equal.addMouseListener(new OperationMouseListener());

add.addMouseListener(new CalcMouseListener());
sub.addMouseListener(new CalcMouseListener());
mul.addMouseListener(new CalcMouseListener());
div.addMouseListener(new CalcMouseListener());

zero.addMouseListener(new NumberMouseListener());
one.addMouseListener(new NumberMouseListener());
two.addMouseListener(new NumberMouseListener());
three.addMouseListener(new NumberMouseListener());
four.addMouseListener(new NumberMouseListener());
five.addMouseListener(new NumberMouseListener());
six.addMouseListener(new NumberMouseListener());
seven.addMouseListener(new NumberMouseListener());
eight.addMouseListener(new NumberMouseListener());
nine.addMouseListener(new NumberMouseListener());

f.setVisible(true);
f.pack();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

private class NumberMouseListener implements MouseListener{

public void mouseClicked(MouseEvent e) {
if(input.getText().trim().equals("0")){
input.setText(((JButton)e.getSource()).getText().trim());
}else{
input.setText(input.getText().concat(((JButton)e.getSource()).getText().trim()));
}
}

public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}

private class CalcMouseListener implements MouseListener{

public void mouseClicked(MouseEvent e) {
num1 = input.getText().trim();input.setText("");
operator = ((JButton)e.getSource()).getText().trim();
}

public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}

private class OperationMouseListener implements MouseListener{

public void mouseClicked(MouseEvent e) {
if(e.getSource() == backspace){
String inputText = input.getText();
if(inputText.length() > 0){
input.setText(inputText.substring(0, inputText.length() - 1));
}
}else if(e.getSource() == C){
input.setText("0");
num1 = "";
}else if(e.getSource() == CE){
input.setText("0");
}else if(e.getSource() == decimal){
String text = input.getText().trim();

if(text.indexOf(".") == -1){
input.setText(text.concat("."));
}
}else if(e.getSource() == equal){
if(!operator.trim().equals("")){
if(!input.getText().trim().equals("")){
double result = 0D;
if(operator.equals("+")){
result = Double.parseDouble(num1) + Double.parseDouble(input.getText().trim());
}else if(operator.equals("-")){
result = Double.parseDouble(num1) - Double.parseDouble(input.getText().trim());
}else if(operator.equals("*")){
result = Double.parseDouble(num1) * Double.parseDouble(input.getText().trim());
}else if(operator.equals("/")){
result = Double.parseDouble(num1) / Double.parseDouble(input.getText().trim());
}

input.setText(new DecimalFormat("0.00").format(result));
}
}

}

}

public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}

}

⑵ java計算器程序

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class Calculator extends JFrame

{

private Container container;

private GridBagLayout layout;

private GridBagConstraints constraints;

private JTextField displayField;//計算結果顯示區

private String lastCommand;//保存+,-,*,/,=命令

private double result;//保存計算結果

private boolean start;//判斷是否為數字的開始

public Calculator()

{

super("Calculator");

container=getContentPane();

layout=new GridBagLayout();

container.setLayout(layout);

constraints=new GridBagConstraints();

start=true;

result=0;

lastCommand = "=";

displayField=new JTextField(20);

displayField.setHorizontalAlignment(JTextField.RIGHT);

constraints.gridx=0;

constraints.gridy=0;

constraints.gridwidth=4;

constraints.gridheight=1;

constraints.fill=GridBagConstraints.BOTH;

constraints.weightx=100;

constraints.weighty=100;

layout.setConstraints(displayField,constraints);

container.add(displayField);

ActionListener insert = new InsertAction();

ActionListener command = new CommandAction();

addButton("Backspace",0,1,2,1,insert);

addButton("CE",2,1,1,1,insert);

addButton("C",3,1,1,1,insert);

addButton("7",0,2,1,1,insert);

addButton("8",1,2,1,1,insert);

addButton("9",2,2,1,1,insert);

addButton("/",3,2,1,1,command);

addButton("4",0,3,1,1,insert);

addButton("5",1,3,1,1,insert);

addButton("6",2,3,1,1,insert);

addButton("*",3,3,1,1,command);

addButton("1",0,4,1,1,insert);

addButton("2",1,4,1,1,insert);

addButton("3",2,4,1,1,insert);

addButton("-",3,4,1,1,command);

addButton("0",0,5,1,1,insert);

addButton("+/-",1,5,1,1,insert);//只顯示"-"號,"+"沒有實用價值

addButton(".",2,5,1,1,insert);

addButton("+",3,5,1,1,command);

addButton("=",0,6,4,1,command);

setSize(300,300);

setVisible(true);

}

private void addButton(String label,int row,int column,int with,int height,ActionListener listener)

{

JButton button=new JButton(label);

constraints.gridx=row;

constraints.gridy=column;

constraints.gridwidth=with;

constraints.gridheight=height;

constraints.fill=GridBagConstraints.BOTH;

button.addActionListener(listener);

layout.setConstraints(button,constraints);

container.add(button);

}

private class InsertAction implements ActionListener

{

public void actionPerformed(ActionEvent event)

{

String input=event.getActionCommand();

if (start)

{

displayField.setText("");

start=false;

if(input.equals("+/-"))

displayField.setText(displayField.getText()+"-");

}

if(!input.equals("+/-"))

{

if(input.equals("Backspace"))

{

String str=displayField.getText();

if(str.length()>0)

displayField.setText(str.substring(0,str.length()-1));

}

else if(input.equals("CE")||input.equals("C"))

{

displayField.setText("0");

start=true;

}

else

displayField.setText(displayField.getText()+input);

}

}

}

private class CommandAction implements ActionListener

{

public void actionPerformed(ActionEvent evt)

{

String command=evt.getActionCommand();

if(start)

{

lastCommand=command;

}

else

{

calculate(Double.parseDouble(displayField.getText()));

lastCommand=command;

start=true;

}

}

}

public void calculate(double x)

{

if (lastCommand.equals("+")) result+= x;

else if (lastCommand.equals("-")) result-=x;

else if (lastCommand.equals("*")) result*=x;

else if (lastCommand.equals("/")) result/=x;

else if (lastCommand.equals("=")) result=x;

displayField.setText(""+ result);

}

public static void main(String []args)

{

Calculator calculator=new Calculator();

calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

}

⑶ 用JAVA設計一個計算器程序

我有，你聯系我，我把代碼給你！ 為了防止別人以為我們作弊了，在這里給出前半段代碼……

package MyProject;

import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import javax.swing.*;
public class Counter extends Frame
{
//聲明三個面板的布局
GridLayout gl1,gl2,gl3;
Panel p0,p1,p2,p3;
JTextField tf1;
TextField tf2;
Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19,b20,b21,b22,b23,b24,b25,b26;
StringBuffer str;//顯示屏所顯示的字元串
double x,y;//x和y都是運算數
int z;//Z表示單擊了那一個運算符.0表示"+",1表示"-",2表示"*",3表示"/"
static double m;//記憶的數字
public Counter()
{
gl1=new GridLayout(1,4,10,0);//實例化三個面板的布局
gl2=new GridLayout(4,1,0,15);
gl3=new GridLayout(4,5,10,15);

tf1=new JTextField(27);//顯示屏
tf1.setHorizontalAlignment(JTextField.RIGHT);
tf1.setEnabled(false);
tf1.setText("0");
tf2=new TextField(10);//顯示記憶的索引值
tf2.setEditable(false);
//實例化所有按鈕、設置其前景色並注冊監聽器
b0=new Button("Backspace");
b0.setForeground(Color.red);
b0.addActionListener(new Bt());
b1=new Button("CE");
b1.setForeground(Color.red);
b1.addActionListener(new Bt());
b2=new Button("C");
b2.setForeground(Color.red);
b2.addActionListener(new Bt());
b3=new Button("MC");
b3.setForeground(Color.red);
b3.addActionListener(new Bt());
b4=new Button("MR");
b4.setForeground(Color.red);
b4.addActionListener(new Bt());
b5=new Button("MS");
b5.setForeground(Color.red);
b5.addActionListener(new Bt());
b6=new Button("M+");
b6.setForeground(Color.red);
b6.addActionListener(new Bt());
b7=new Button("7");
b7.setForeground(Color.blue);
b7.addActionListener(new Bt());
b8=new Button("8");
b8.setForeground(Color.blue);
b8.addActionListener(new Bt());
b9=new Button("9");
b9.setForeground(Color.blue);
b9.addActionListener(new Bt());
b10=new Button("/");
b10.setForeground(Color.red);
b10.addActionListener(new Bt());
b11=new Button("sqrt");
b11.setForeground(Color.blue);
b11.addActionListener(new Bt());
b12=new Button("4");
b12.setForeground(Color.blue);
b12.addActionListener(new Bt());
b13=new Button("5");
b13.setForeground(Color.blue);
b13.addActionListener(new Bt());
b14=new Button("6");
b14.setForeground(Color.blue);
b14.addActionListener(new Bt());
b15=new Button("*");
b15.setForeground(Color.red);
b15.addActionListener(new Bt());
b16=new Button("%");
b16.setForeground(Color.blue);
b16.addActionListener(new Bt());
b17=new Button("1");
b17.setForeground(Color.blue);
b17.addActionListener(new Bt());
b18=new Button("2");
b18.setForeground(Color.blue);
b18.addActionListener(new Bt());
b19=new Button("3");
b19.setForeground(Color.blue);
b19.addActionListener(new Bt());
b20=new Button("-");
b20.setForeground(Color.red);
b20.addActionListener(new Bt());
b21=new Button("1/X");
b21.setForeground(Color.blue);
b21.addActionListener(new Bt());
b22=new Button("0");
b22.setForeground(Color.blue);
b22.addActionListener(new Bt());
b23=new Button("+/-");
b23.setForeground(Color.blue);
b23.addActionListener(new Bt());
b24=new Button(".");
b24.setForeground(Color.blue);
b24.addActionListener(new Bt());
b25=new Button("+");
b25.setForeground(Color.red);
b25.addActionListener(new Bt());
b26=new Button("=");
b26.setForeground(Color.red);
b26.addActionListener(new Bt());

//實例化四個面板
p0=new Panel();
p1=new Panel();
p2=new Panel();
p3=new Panel();
//創建一個空字元串緩沖區
str=new StringBuffer();

//添加面板p0中的組件和設置其在框架中的位置和大小
p0.add(tf1);
p0.setBounds(10,25,300,40);
//添加面板p1中的組件和設置其在框架中的位置和大小
p1.setLayout(gl1);
p1.add(tf2);
p1.add(b0);
p1.add(b1);
p1.add(b2);
p1.setBounds(10,65,300,25);
//添加面板p2中的組件並設置其的框架中的位置和大小
p2.setLayout(gl2);
p2.add(b3);
p2.add(b4);
p2.add(b5);
p2.add(b6);
p2.setBounds(10,110,40,150);
//添加面板p3中的組件並設置其在框架中的位置和大小
p3.setLayout(gl3);//設置p3的布局
p3.add(b7);
p3.add(b8);
p3.add(b9);
p3.add(b10);
p3.add(b11);
p3.add(b12);
p3.add(b13);
p3.add(b14);
p3.add(b15);
p3.add(b16);
p3.add(b17);
p3.add(b18);
p3.add(b19);
p3.add(b20);
p3.add(b21);
p3.add(b22);
p3.add(b23);
p3.add(b24);
p3.add(b25);
p3.add(b26);
p3.setBounds(60,110,250,150);
//設置框架中的布局為空布局並添加4個面板
setLayout(null);
add(p0);
add(p1);
add(p2);
add(p3);
setResizable(false);//禁止調整框架的大小
//匿名類關閉窗口
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e1)
{
MainFrame.getMyMainFrame().setEnabled(true);
Counter.this.dispose();
}
});
setBackground(Color.lightGray);
setBounds(100,100,320,280);
setVisible(true);

}

⑷ java編寫計算器的源程序

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Calculator extends JFrame implements ActionListener {
private JFrame jf;
private JButton[] allButtons;
private JButton clearButton;
private JTextField jtf;
public Calculator() {
//對圖形組件實例化
jf=new JFrame("任靜的計算器1.0：JAVA版");
jf.addWindowListener(new WindowAdapter(){
public void windowClosing(){
System.exit(0);
}
});
allButtons=new JButton[16];
clearButton=new JButton("清除");
jtf=new JTextField(25);
jtf.setEditable(false);
String str="123+456-789*0.=/";
for(int i=0;i<allButtons.length;i++){
allButtons[i]=new JButton(str.substring(i,i+1));

}

}
public void init(){
//完成布局
jf.setLayout(new BorderLayout());
JPanel northPanel=new JPanel();
JPanel centerPanel=new JPanel();
JPanel southPanel=new JPanel();
northPanel.setLayout(new FlowLayout());
centerPanel.setLayout(new GridLayout(4,4));
southPanel.setLayout(new FlowLayout());

northPanel.add(jtf);
for(int i=0;i<16;i++){
centerPanel.add(allButtons[i]);
}
southPanel.add(clearButton);

jf.add(northPanel,BorderLayout.NORTH);
jf.add(centerPanel,BorderLayout.CENTER);
jf.add(southPanel,BorderLayout.SOUTH);
addEventHandler();
}
//添加事件監聽
public void addEventHandler(){
jtf.addActionListener(this);
for(int i=0;i<allButtons.length;i++){

allButtons[i].addActionListener(this);

}

clearButton.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
Calculator.this.jtf.setText("");
}

});

}

//事件處理

public void actionPerformed(ActionEvent e) {
//在這里完成事件處理 使計算器可以運行
String action=e.getActionCommand();
if(action=="+"||action=="-"||action=="*"||action=="/"){

}

}
public void setFontAndColor(){
Font f=new Font("宋體",Font.BOLD,24);
jtf.setFont(f);
jtf.setBackground(new Color(0x8f,0xa0,0xfb));
for(int i=0;i<16;i++){
allButtons[i].setFont(f);
allButtons[i].setForeground(Color.RED);
}
}

public void showMe(){
init();
setFontAndColor();
jf.pack();
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String[] args){
new Calculator().showMe();
}
}

⑸ 用java編寫簡易計算器程序

//布局沒有調整，需要你自己去調整
代碼如下：
importjava.awt.FlowLayout;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;

importjavax.swing.*;

{
	
	JTextFieldc1;
	JTextFieldc2;
	JLabelc;
	JLabelequal=newJLabel("=");
	JLabelresult;
	JLabelchoose=newJLabel("請選擇");
	JButtonadd=newJButton("+");
	JButtonsub=newJButton("-");
	JButtonmul=newJButton("×");
	JButtondiv=newJButton("÷");
	
	JButtoncal=newJButton("計算");
	JButtonclear=newJButton("清除");
	
	publicJieMian(){
		(newFlowLayout());
		c1=newJTextField(5);
		c2=newJTextField(5);
		c=newJLabel("+");
		result=newJLabel("");
		add(c1);
		add(c);
		add(c2);
		add(equal);
		add(result);
		add(choose);
		add(add);
		add(sub);
		add(mul);
		add(div);
		add(cal);
		add(clear);
		add.addActionListener(this);
		sub.addActionListener(this);
		mul.addActionListener(this);
		div.addActionListener(this);
		cal.addActionListener(this);
		clear.addActionListener(this);
		setVisible(true);
		pack();
	}
	
	@Override
	publicvoidactionPerformed(ActionEvente){
		if(e.getSource()==add){
			c.setText("+");
		}elseif(e.getSource()==sub){
			c.setText("-");
		}elseif(e.getSource()==mul){
			c.setText("×");
		}elseif(e.getSource()==div){
			c.setText("÷");
		}elseif(e.getSource()==cal){
			doublecc1,cc2;
			try{
				cc1=Double.parseDouble(c1.getText());
			}catch(Exceptionex){
				cc1=0;
			}try{
				cc2=Double.parseDouble(c2.getText());
			}catch(Exceptionex){
				cc2=0;
			}
			if(c.getText()=="+"){
				result.setText(String.valueOf(cc1+cc2));
			}elseif(c.getText()=="-"){
				result.setText(String.valueOf(cc1-cc2));
			}elseif(c.getText()=="×"){
				result.setText(String.valueOf(cc1*cc2));
			}elseif(c.getText()=="÷"){
				if(cc2!=0){
					result.setText(String.valueOf(cc1/cc2));
				}else{
					result.setText("NAN");
				}
			}
		}elseif(e.getSource()==clear){
			c1.setText("");
			c2.setText("");
			result.setText("");
		}
	}
	
	publicstaticvoidmain(Stringargs[]){
		JieMianjiemian=newJieMian();
	}
	
}

⑹ 用Java編寫一個簡單的計算器程序

import java.awt.*;
import java.awt.event.*;

public class CalcAppDemo extends Frame{
private TextField t_result;
private Panel p_main; //主面板
private Panel p_num; //數字面板
private Panel p_oper; //操作符面板
private Panel p_show; //顯示面板
private Button b_num[]; //數字按鈕
private Button b_oper[]; //操作符面板

public CalcAppDemo(String title){
setTitle(title);
t_result = new TextField("0.0", 21);
p_main = new Panel();
p_num = new Panel();
p_oper = new Panel();
p_show = new Panel();
p_main.setLayout(new BorderLayout());
p_num.setLayout(new GridLayout(4, 3, 1, 1));
p_oper.setLayout(new GridLayout(4, 2, 1, 1));

b_num = new Button[12];
for(int i=0; i<9; i++)
{
b_num[i] = new Button(new Integer(i+1).toString());
}
b_num[9] = new Button("0");
b_num[10] = new Button("cls");
b_num[11] = new Button(".");
for(int i=0; i<12; i++)
{
p_num.add(b_num[i]);
}

b_oper = new Button[8];
b_oper[0] = new Button("+");
b_oper[1] = new Button("-");
b_oper[2] = new Button("*");
b_oper[3] = new Button("/");
b_oper[4] = new Button("pow");
b_oper[5] = new Button("sqrt");
b_oper[6] = new Button("+/-");
b_oper[7] = new Button("=");
for(int i=0; i<8; i++) //
{
p_oper.add(b_oper[i]);
}

t_result.setEditable(false);
p_show.add(t_result, BorderLayout.NORTH);
p_main.add(p_show, BorderLayout.NORTH);
p_main.add(p_num, BorderLayout.WEST);
p_main.add(p_oper, BorderLayout.EAST);
this.add(p_main, BorderLayout.CENTER);
setSize(400, 400);
setResizable(false);
pack();

this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
ButtonListener b1 = new ButtonListener();
for(int i=0; i<12; i++)
{
b_num[i].addActionListener(b1);
}
for(int i=0; i<8; i++)
{
b_oper[i].addActionListener(b1);
}
}

class ButtonListener implements ActionListener
{
private String lastOp; //存儲上一此操作符
private String strVal; //存儲數字對應的字元串
private double total; //總數
private double number; //存儲新輸入的數
private boolean firsttime; //判斷是否第一次按下的是操作符按鈕
private boolean operatorPressed;//判斷是否已經按過操作符按鈕

ButtonListener()
{
firsttime = true;
strVal = "";
}

//事件處理器
public void actionPerformed(ActionEvent e)
{
String s = ((Button)e.getSource()).getLabel().trim();

if(Character.isDigit(s.charAt(0)))
{//判斷是操作數還是操作符
handleNumber(s);
}
else
{
calculate(s);
}
}

//判斷是一元操作符還是二元操作符，並根據操作符類型做計算
void calculate(String op)
{
operatorPressed = true;

if(firsttime&&! isUnary(op))
{
total = getNumberOnDisplay();
firsttime = false;
}
if(isUnary(op))
{
handleUnaryOp(op);
}
else if(lastOp != null)
{
handleBinaryOp(lastOp);
}
if(! isUnary(op))
{
lastOp = op;
}
}

//判斷是否一元操作符
boolean isUnary(String s)
{
return s.equals("=")
||s.equals("cls")||s.equals("sqrt")
||s.equals("+/-")||s.equals(".");
}

//處理一元操作符
void handleUnaryOp(String op)
{
if(op.equals("+/-"))
{//
number = negate(getNumberOnDisplay() + "");
t_result.setText("");
t_result.setText(number + "");
return;
}else if(op.equals("."))
{
handleDecPoint();
return;
}else if(op.equals("sqrt"))
{
number = Math.sqrt(getNumberOnDisplay());
t_result.setText("");
t_result.setText(number + "");
return;
}else if(op.equals("="))
{//
if(lastOp!= null && !isUnary(lastOp))
{
handleBinaryOp(lastOp);
}
lastOp = null;
firsttime = true;
return;
}else
{
clear();
}
}

//處理二元運算符
void handleBinaryOp(String op)
{
if(op.equals("+"))
{
total +=number;
}else if(op.equals("-"))
{
total -=number;
}else if(op.equals("*"))
{
total *=number;
}else if(op.equals("/"))
{
try
{
total /=number;
}catch(ArithmeticException ae){}
}else if(op.equals("pow"))
total = Math.pow(total, number);
//t_result.setText("");
lastOp = null;
// strVal = "";
number = 0;
t_result.setText(total + "");
}

//該方法用於處理數字按鈕
void handleNumber(String s)
{
if(!operatorPressed)
{
strVal += s;
}else
{
operatorPressed = false;
strVal = s;
}
//
number = new Double(strVal).doubleValue();
t_result.setText("");
t_result.setText(strVal);
}

//該方法用於按下"."按鈕
void handleDecPoint()
{
operatorPressed = false;
//
if(strVal.indexOf(".")<0)
{
strVal += ".";
}
t_result.setText("");
t_result.setText(strVal);
}

//該方法用於將一個數求反
double negate(String s)
{
operatorPressed = false;
//如果是一個整數，去掉小數點後面的0
if(number == (int)number)
{
s = s.substring(0,s.indexOf("."));
}

//如果無"-"增加在該數的前面
if(s.indexOf("-")<0)
{
strVal = "-" + s;
}
else
{
strVal = s.substring(1);
}
return new Double(strVal).doubleValue();
}

//將顯示框中的值轉換成Double
double getNumberOnDisplay()
{
return new Double(t_result.getText()).doubleValue();
}

//清除屏幕並設置所有的標識
void clear()
{
firsttime = true;
lastOp = null;
strVal = "";
total = 0;
number = 0;
t_result.setText("0");
}
}

public static void main(String[] args) {
CalcAppDemo c = new CalcAppDemo("簡單的計算器程序");
c.setVisible(true);
}

}

⑺ 用JAVA實現一個計算器的應用程序

/**
@version 1.32 2004-05-05
@author Cay Horstmann
*/

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

public class Calculator
{
public static void main(String[] args)
{
CalculatorFrame frame = new CalculatorFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}

/**
A frame with a calculator panel.
*/
class CalculatorFrame extends JFrame
{
public CalculatorFrame()
{
setTitle("Calculator");
CalculatorPanel panel = new CalculatorPanel();
add(panel);
pack();
}
}

/**
A panel with calculator buttons and a result display.
*/
class CalculatorPanel extends JPanel
{
public CalculatorPanel()
{
setLayout(new BorderLayout());

result = 0;
lastCommand = "=";
start = true;

// add the display

display = new JButton("0");
display.setEnabled(false);
add(display, BorderLayout.NORTH);

ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();

// add the buttons in a 4 x 4 grid

panel = new JPanel();
panel.setLayout(new GridLayout(4, 4));

addButton("7", insert);
addButton("8", insert);
addButton("9", insert);
addButton("/", command);

addButton("4", insert);
addButton("5", insert);
addButton("6", insert);
addButton("*", command);

addButton("1", insert);
addButton("2", insert);
addButton("3", insert);
addButton("-", command);

addButton("0", insert);
addButton(".", insert);
addButton("=", command);
addButton("+", command);

add(panel, BorderLayout.CENTER);
}

/**
Adds a button to the center panel.
@param label the button label
@param listener the button listener
*/
private void addButton(String label, ActionListener listener)
{
JButton button = new JButton(label);
button.addActionListener(listener);
panel.add(button);
}

/**
This action inserts the button action string to the
end of the display text.
*/
private class InsertAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
String input = event.getActionCommand();
if (start)
{
display.setText("");
start = false;
}
display.setText(display.getText() + input);
}
}

/**
This action executes the command that the button
action string denotes.
*/
private class CommandAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
String command = event.getActionCommand();

if (start)
{
if (command.equals("-"))
{
display.setText(command);
start = false;
}
else
lastCommand = command;
}
else
{
calculate(Double.parseDouble(display.getText()));
lastCommand = command;
start = true;
}
}
}

/**
Carries out the pending calculation.
@param x the value to be accumulated with the prior result.
*/
public void calculate(double x)
{
if (lastCommand.equals("+")) result += x;
else if (lastCommand.equals("-")) result -= x;
else if (lastCommand.equals("*")) result *= x;
else if (lastCommand.equals("/")) result /= x;
else if (lastCommand.equals("=")) result = x;
display.setText("" + result);
}

private JButton display;
private JPanel panel;
private double result;
private String lastCommand;
private boolean start;
}

為java核心技術的計算器實現的程序，o(∩_∩)o...哈哈

⑻ java簡單計算器程序

importjava.awt.*;
importjava.awt.event.*;
importjavax.swing.*;

{
privateJTextFieldtext_operate1,text_operate2,text_result;
privateButtonbutton_add,button_minus,button_multiply,button_divide;

publicCaculator(){
super("計算器");
this.setBounds(300,300,560,180);//30030056090
this.setResizable(true);//setReaizable
this.setBackground(java.awt.Color.lightGray);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setLayout(newGridLayout(3,3,5,5));//GidLayout
this.getContentPane().add(newJLabel("操作數"));
text_operate1=newJTextField(5);
this.getContentPane().add(text_operate1);
this.getContentPane().add(newJLabel("操作數"));
text_operate2=newJTextField(5);
this.getContentPane().add(text_operate2);
button_add=newButton("+");
this.getContentPane().add(button_add);
button_add.addActionListener(this);//addCaretListener
button_minus=newButton("-");
this.getContentPane().add(button_minus);
button_minus.addActionListener(this);
button_multiply=newButton("x");
this.getContentPane().add(button_multiply);
button_multiply.addActionListener(this);
button_divide=newButton("/");
this.getContentPane().add(button_divide);//getContentPane
button_divide.addActionListener(this);
this.getContentPane().add(newJLabel("結果"));
text_result=newJTextField(10);
text_result.setHorizontalAlignment(JTextField.RIGHT);//setHororizontalAlignment
text_result.setEditable(false);
this.getContentPane().add(text_result);
this.setVisible(true);//setVisable
//actionPerformed(null);
}

publicvoidactionPerformed(ActionEventev)//publicint
{
if(ev.getSource()==button_add){
Stringstr=text_operate1.getText();
Stringstr1=text_operate2.getText();
intuni=Integer.parseInt(str);
intuni1=Integer.parseInt(str1);
//inttext_result=uni+uni1;
//returntext_result;
text_result.setText((uni+uni1)+"");

}elseif(ev.getSource()==button_minus){
Stringstr=text_operate1.getText();
Stringstr1=text_operate2.getText();
intuni=Integer.parseInt(str);
intuni1=Integer.parseInt(str1);
//inttext_result=uni-uni1;
//returntext_result;
text_result.setText((uni-uni1)+"");
}elseif(ev.getSource()==button_multiply){
Stringstr=text_operate1.getText();
Stringstr1=text_operate2.getText();
intuni=Integer.parseInt(str);
intuni1=Integer.parseInt(str1);
//inttext_result=uni*uni1;
//returntext_result;
text_result.setText((uni*uni1)+"");
}elseif(ev.getSource()==button_divide){
Stringstr=text_operate1.getText();
Stringstr1=text_operate2.getText();
intuni=Integer.parseInt(str);
intuni1=Integer.parseInt(str1);
//inttext_result=uni/uni1;
//returntext_result;
text_result.setText(uni/uni1+"");
}
}

publicstaticvoidmain(Stringargs[]){
newCaculator();
}
}