java设计计算器
1. java设计一个简单的计算器，要求根据输入的操作数和运算符(+-*/)计算其值
include<iostream>
float a,b,m=1;
string n;
while(m==1){
cin>>a>>b;
cin>>n;
switch(n){
case `+` : cout<<a<<"+"<<b<<"="<<a+b
<<end1;
break;
case `-` : cout<<a<<"-"<<b<<"="<<a-b
<<end1;
break;
case `*` : cout<<a<<"*"<<b<<"="<<a*b
<<end1;
break;
case `/` : cout<<a<<"/"<<b<<"="<<a/b
<<end1;
break;
case `%` : cout<<a<<"%"<<b<<"="<<a%b
<<end1;
break;
defult: cout<<"输入错误，请检查"
<<end1;
}
cout<<"按1继续，其他键退出:";
cin>>m;
}
2. 用java设计计算器
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
public class calculator extends JFrame implements ActionListener
{//这里我把JFrame写成Frame，这个错误找了好久
JFrame frame;
private JButton jia=new JButton("+");
private JButton jian=new JButton("-");
private JButton cheng=new JButton("*");
private JButton chu=new JButton("/");
private JButton qiuyi=new JButton("%");
private JButton deng=new JButton("=");
private JButton fu=new JButton("+/-");
private JButton dian=new JButton(".");
private JButton kai=new JButton("sqrt");
private JButton diao=new JButton("1/x");
private JButton aa=new JButton("A");
private JButton bb=new JButton("B");
private JButton cc=new JButton("C");
private JButton dd=new JButton("D");
private JButton ee=new JButton("E");
private JButton ff=new JButton("F");
private TextField k1=new TextField();
private objConversion convert = new objConversion();
JMenuItem ,paste,s,t,help,about,me;
JRadioButton sixteen,ten,eight,two;
JButton backspace,ce,c,num0,num1,num2,num3,num4,num5,num6,num7,num8,num9;
Container cp;
JTextField text;
String content="";
boolean clickable=true,clear=true;
int all=0;
double qian;
String fuhao;
int jin=10,first=1;
public calculator()
{
setTitle("计算器－杨彩制作");
setSize(400,300);
setLocation(250,200);
text=new JTextField(25);
// text.setEnabled(false);
text.setText("0.");
text.setHorizontalAlignment(JTextField.RIGHT);//从右到左
JPanel cp1=new JPanel();
JPanel cp2=new JPanel();
JPanel cp3=new JPanel();
cp=getContentPane();
cp.add(cp1,"North");
cp.add(cp2,"Center");
cp.add(cp3,"South");
cp1.setLayout(new GridLayout(1,6));
cp2.setLayout(new GridLayout(2,4));
cp3.setLayout(new GridLayout(6,6));
sixteen=new JRadioButton("十六进制");
sixteen.setVisible(false);
ten=new JRadioButton("十进制",true);
ten.setVisible(false);
eight=new JRadioButton("八进制");
eight.setVisible(false);
two=new JRadioButton("二进制");
two.setVisible(false);
sixteen.addActionListener(this);
ten.addActionListener(this);
eight.addActionListener(this);
two.addActionListener(this);
ButtonGroup btg=new ButtonGroup();
btg.add(sixteen);
btg.add(ten);
btg.add(eight);
btg.add(two);
JTextField t3=new JTextField(25);
cp1.add(text);
// text.setEnabled(false);
text.setEditable(false);
text.setBackground(new Color(255, 255, 255));
cp2.add(sixteen);
cp2.add(ten);
cp2.add(eight);
cp2.add(two);
backspace=new JButton("Backspace");
backspace.setForeground(new Color(255,0,0));
backspace.addActionListener(this);
ce=new JButton("CE");
ce.setForeground(new Color(255,0,0));
ce.addActionListener(this);
c=new JButton("C");
c.setForeground(new Color(255,0,0));
c.addActionListener(this);
k1.setVisible(false);
cp2.add(k1);
cp2.add(backspace);
cp2.add(ce);
cp2.add(c);
num0=new JButton("0");
num1=new JButton("1");
num2=new JButton("2");
num3=new JButton("3");
num4=new JButton("4");
num5=new JButton("5");
num6=new JButton("6");
num7=new JButton("7");
num8=new JButton("8");
num9=new JButton("9");
cp3.add(num7);
num7.addActionListener(this);
cp3.add(num8);
num8.addActionListener(this);
cp3.add(num9);
num9.addActionListener(this);
cp3.add(chu);
chu.setForeground(new Color(255,0,0));
chu.addActionListener(this);
cp3.add(kai);
kai.addActionListener(this);
cp3.add(num4);
num4.addActionListener(this);
cp3.add(num5);
num5.addActionListener(this);
cp3.add(num6);
num6.addActionListener(this);
cp3.add(cheng);
cheng.setForeground(new Color(255,0,0));
cheng.addActionListener(this);
cp3.add(qiuyi);
qiuyi.addActionListener(this);
cp3.add(num1);
num1.addActionListener(this);
cp3.add(num2);
num2.addActionListener(this);
cp3.add(num3);
num3.addActionListener(this);
cp3.add(jian);
jian.setForeground(new Color(255,0,0));
jian.addActionListener(this);
cp3.add(diao);
diao.addActionListener(this);
cp3.add(num0);
num0.addActionListener(this);
cp3.add(fu);
fu.addActionListener(this);
cp3.add(dian);
dian.addActionListener(this);
cp3.add(jia);
jia.setForeground(new Color(255,0,0));
jia.addActionListener(this);
cp3.add(deng);
deng.setForeground(new Color(255,0,0));
deng.addActionListener(this);
cp3.add(aa);
aa.addActionListener(this);
cp3.add(bb);
bb.addActionListener(this);
cp3.add(cc);
cc.addActionListener(this);
cp3.add(dd);
dd.addActionListener(this);
cp3.add(ee);
ee.addActionListener(this);
cp3.add(ff);
ff.addActionListener(this);
aa.setVisible(false);
bb.setVisible(false);
cc.setVisible(false);
dd.setVisible(false);
ee.setVisible(false);
ff.setVisible(false);
JMenuBar mainMenu = new JMenuBar();
setJMenuBar(mainMenu);
JMenu editMenu = new JMenu("编辑");
JMenu viewMenu = new JMenu("查看");
JMenu helpMenu = new JMenu("帮助");
mainMenu.add(editMenu);
mainMenu.add(viewMenu);
mainMenu.add(helpMenu);
= new JMenuItem(" 复制");
paste = new JMenuItem(" 粘贴");
KeyStroke ks=KeyStroke.getKeyStroke(KeyEvent.VK_C,Event.CTRL_MASK);
.setAccelerator(ks);//设置退出菜单选项加上快捷键
KeyStroke pasteks=KeyStroke.getKeyStroke(KeyEvent.VK_V,Event.CTRL_MASK);
paste.setAccelerator(pasteks);//设置退出菜单选项加上快捷键
editMenu.add();
editMenu.add(paste);
.addActionListener(this);
paste.addActionListener(this);
t = new JMenuItem("●标准型");
s = new JMenuItem(" 科学型");
viewMenu.add(t);
viewMenu.add(s);
t.addActionListener(this);
s.addActionListener(this);
help = new JMenuItem(" 帮助主题");
about = new JMenuItem(" 关于计算器");
me = new JMenuItem(" 作者主页");
helpMenu.add(help);
helpMenu.add(about);
helpMenu.add(me);
help.addActionListener(this);
about.addActionListener(this);
me.addActionListener(this);
addWindowListener(new WindowDestroyer());//结束窗口
}
public void actionPerformed(ActionEvent e)
{//响应动作代码
if(first==1)
text.setText("");
first=0;//第一次把文本框0.清空
Object temp = e.getSource();
if(temp==)
{
content = text.getText();
}
if(temp==paste)
{
text.setText(text.getText()+content);
}
if(temp==t)
{//标准
sixteen.setVisible(false);
ten.setVisible(false);
eight.setVisible(false);
two.setVisible(false);
t.setText("●标准型");
s.setText(" 科学型");
aa.setVisible(false);
bb.setVisible(false);
cc.setVisible(false);
dd.setVisible(false);
ee.setVisible(false);
ff.setVisible(false);
}
if(temp==s)
{//科学
sixteen.setVisible(true);
ten.setVisible(true);
eight.setVisible(true);
two.setVisible(true);
t.setText(" 标准型");
s.setText("●科学型");
aa.setVisible(true);
bb.setVisible(true);
cc.setVisible(true);
dd.setVisible(true);
ee.setVisible(true);
ff.setVisible(true);
aa.setEnabled(false);
bb.setEnabled(false);
cc.setEnabled(false);
dd.setEnabled(false);
ee.setEnabled(false);
ff.setEnabled(false);
}
if(temp==help)
{ //打开系统帮助文件 要查资料
try
{
String filePath = "C:/WINDOWS/Help/calc.chm";
Runtime.getRuntime().exec("cmd.exe /c "+filePath);
}
catch(Exception eeee)
{
System.out.println("打开系统的计算器出错");
}
}
if(temp==about)
{
JOptionPane.showMessageDialog(frame," Java计算器 杨彩 制作 http://blog.sina.com.cn/m/yangcai","关于计算器",JOptionPane.INFORMATION_MESSAGE); ;
}
if(temp==me)
{
try
{
Process p = Runtime.getRuntime().exec("explorer http://blog.sina.com.cn/m/yangcai");
}
catch(Exception eeee)
{
System.out.println("打开指定网页出错");
}
}
try
{
if(temp==sixteen)
{
String hex=text.getText();
int inthex=Integer.parseInt(hex,jin);//先把数变为10进制
text.setText(convert.decHex(inthex)) ;
jin=16;
aa.setEnabled(true);
bb.setEnabled(true);
cc.setEnabled(true);
dd.setEnabled(true);
ee.setEnabled(true);
ff.setEnabled(true);
num2.setEnabled(true);
num3.setEnabled(true);
num4.setEnabled(true);
num5.setEnabled(true);
num6.setEnabled(true);
num7.setEnabled(true);
num8.setEnabled(true);
num9.setEnabled(true);
}
if(temp==eight)
{
String oct =text.getText();
int intoct=Integer.parseInt(oct,jin);
text.setText(convert.decOct(intoct)) ;
jin=8;
aa.setEnabled(false);
bb.setEnabled(false);
cc.setEnabled(false);
dd.setEnabled(false);
ee.setEnabled(false);
ff.setEnabled(false);
num2.setEnabled(true);
num3.setEnabled(true);
num4.setEnabled(true);
num5.setEnabled(true);
num6.setEnabled(true);
num7.setEnabled(true);
num8.setEnabled(false);
num9.setEnabled(false);
}
if(temp==two)
{
String bin=text.getText();
int intbin=Integer.parseInt(bin,jin);
text.setText(convert.decBin(intbin));
jin=2;
aa.setEnabled(false);
bb.setEnabled(false);
cc.setEnabled(false);
dd.setEnabled(false);
ee.setEnabled(false);
ff.setEnabled(false);
num2.setEnabled(false);
num3.setEnabled(false);
num4.setEnabled(false);
num5.setEnabled(false);
num6.setEnabled(false);
num7.setEnabled(false);
num8.setEnabled(false);
num9.setEnabled(false);
}
if(temp==ten)
{
String dec=text.getText();
int intdec=Integer.parseInt(dec,jin);
// text.setText(convert.decDec(intdec)); //本句会把123变成321
text.setText(intdec+"");
jin=10;
aa.setEnabled(false);
bb.setEnabled(false);
cc.setEnabled(false);
dd.setEnabled(false);
ee.setEnabled(false);
ff.setEnabled(false);
num2.setEnabled(true);
num3.setEnabled(true);
num4.setEnabled(true);
num5.setEnabled(true);
num6.setEnabled(true);
num7.setEnabled(true);
num8.setEnabled(true);
num9.setEnabled(true);
}
}
catch(Exception ee)
{
System.out.println("转换出错,可能你没有输入任何字符");
text.setText("转换出错");
clear=false;
}
if(temp==backspace)
{//退格
String s = text.getText();
text.setText("");
for (int i = 0; i < s.length() - 1; i++)
{
char a = s.charAt(i);
text.setText(text.getText() + a);
}
}
if (temp==ce)
{
text.setText("0.");
clear=true;
first=1;
}
if (temp==c)
{
text.setText("0."); ;
clear=true;
first=1;
}
if(temp==num0)
{
if(clear==false)//判断是否点击了符号位
text.setText("");
text.setText(text.getText()+"0");
}
if(temp==num1)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"1");
clear=true;//第二次不在清空（前二句）
}
if(temp==num2)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"2");
clear=true;
}
if(temp==num3)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"3");
clear=true;
}
if(temp==num4)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"4");
clear=true;
}
if(temp==num5)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"5");
clear=true;
}
if(temp==num6)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"6");
clear=true;
}
if(temp==num7)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"7");
clear=true;
}
if(temp==num8)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"8");
clear=true;
}
if(temp==num9)
{
if(clear==false)
text.setText("");
text.setText(text.getText()+"9");
clear=true;
}
if(temp==aa)
{
text.setText(text.getText()+"A");
}
if(temp==bb)
{
text.setText(text.getText()+"B");
}
if(temp==cc)
{
text.setText(text.getText()+"C");
}
if(temp==dd)
{
text.setText(text.getText()+"D");
}
if(temp==ee)
{
text.setText(text.getText()+"E");
}
if(temp==ff)
{
text.setText(text.getText()+"F");
}
if(temp==dian)
{
clickable=true;
for (int i = 0; i < text.getText().length(); i++)
if ('.' == text.getText().charAt(i))
{
clickable=false;
break;
} //第一层判断是否里面含有小数点;
if(clickable==true)//第二坛判断
text.setText(text.getText()+".");
}
try
{
if(temp==jia)
{//加法
qian=Double.parseDouble(text.getText());
fuhao="+";
clear=false;
}
if(temp==jian)
{
qian=Double.parseDouble(text.getText());
fuhao="-";
clear=false;
;
}
if(temp==cheng)
{
qian=Double.parseDouble(text.getText());
fuhao="*";
clear=false;
}
if(temp==chu)
{
qian=Double.parseDouble(text.getText());
fuhao="/";
clear=false;
}
if(temp==deng)
{
double ss=Double.parseDouble(text.getText());
text.setText("");
if(fuhao=="+")
text.setText(qian+ss+"");
if(fuhao=="-")
text.setText(qian-ss+"");
if(fuhao=="*")
text.setText(qian*ss+"");
if(fuhao=="/")
text.setText(qian/ss+"");
clear=false;//要清空前一次的数据
;
}
if(temp==kai)
{
String s = text.getText();
if (s.charAt(0) == '-')
{
text.setText("负数不能开根号");
}
else
text.setText(Double.toString(java.lang.Math.sqrt(Double.parseDouble(text.getText()))));
clear=false;
}
if(temp==diao)
{
if (text.getText().charAt(0) == '0'&&text.getText().length() == 1)
{
text.setText("除数不能为零");
}
else
{
boolean isDec = true;
int i, j, k;
String s = Double.toString(1 / Double.parseDouble(text.getText()));
for (i = 0; i < s.length(); i++)
if (s.charAt(i) == '.')
break;
for (j = i + 1; j < s.length(); j++)
if (s.charAt(j) != '0')
{
isDec = false;
break;
}
if (isDec == true)
{
String stemp = "";
for (k = 0; k < i; k++)
stemp += s.charAt(k);
text.setText(stemp);
}
else
text.setText(s);
}
clear=false;
}
if(temp==qiuyi)
{
text.setText("0");
clear=false;
}
if (temp == fu)
{ //导师，此方法参考书中例子
boolean isNumber = true;
String s = text.getText();
for (int i = 0; i < s.length(); i++)
if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' ||
s.charAt(i) == '-'))
{
isNumber = false;
break;
}
if (isNumber == true)
{
//如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉
if (s.charAt(0) == '-')
{
text.setText("");
for (int i = 1; i < s.length(); i++)
{
char a = s.charAt(i);
text.setText(text.getText() + a);
}
}
//如果当前字符串第一个字符不是符号，则添加一个符号在首字母处
else
text.setText('-' + s);
}
}
}
catch(Exception eee)
{
System.out.println("运算时,首先输入数字或字符");
text.setText("运算出错");
clear=false;
}
}
class WindowDestroyer extends WindowAdapter
{//退出窗口动作
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
class objConversion
{//导师,本进制类参考了CSMD类转换例子
public void objConversion ()
{
}
public String decDec (int decNum)
{//10
String strDecNum = Integer.toString(decNum);
for (int i = strDecNum.length(); i < 3; i++)
{
strDecNum = "0" + strDecNum;
}
// return strDecNum;
return invert (strDecNum, 5);
}
public String decHex (int decNum)
{//10 to 16
String strHexNum = "";
int currentNum = 0;
while (decNum != 0)
{
if (decNum > 15)
{
currentNum = decNum % 16;
decNum /= 16;
}
else
{
currentNum = decNum;
decNum = 0;
}
switch (currentNum)
{
case 15: strHexNum += "F";
break;
case 14: strHexNum += "E";
break;
case 13: strHexNum += "D";
break;
case 12: strHexNum += "C";
break;
case 11: strHexNum += "B";
break;
case 10: strHexNum += "A";
break;
default: strHexNum += Integer.toString(currentNum);
break;
}
}
return invert (strHexNum, 2);
}
public String decOct (int decNum)
{//10 to 8
String strOctNum = "";
while (decNum != 0)
{
if (decNum > 7)
{
strOctNum += Integer.toString(decNum % 8);
decNum /= 8;
}
else
{
strOctNum += Integer.toString(decNum);
decNum = 0;
}
}
return invert (strOctNum, 3);
}
public String decBin (int decNum)
{//10 to 2
String strBinNum = "";
while (decNum != 0)
{
if (decNum > 1)
{
strBinNum += Integer.toString(decNum % 2);
decNum /= 2;
}
else
{
strBinNum += Integer.toString(decNum);
decNum = 0;
}
}
return invert (strBinNum, 8);
}
private String invert (String strNum, int minLength) //转换长度
{
String answer = "";
int length = strNum.length();
if (length < minLength)
{
for (int padding = (minLength - length); padding > 0; padding--)
{
answer += "0";
}
}
for (int i = length; i > 0; i--)
{
answer += strNum.charAt (i - 1);
}
return answer;
}
}
public static void main(String arg[])//产生窗口
{
calculator win = new calculator();
win.setVisible(true);
}
}
3. 用java程序编写一个计算器
给你一个参考，希望不要被网络吞了当晚餐
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 {
//计算器面板
private JFrame f = new JFrame("Calculator");
//输入面扳
private JPanel inputPanel = new JPanel();
//加减乘除面板
private JPanel operationPanel = new JPanel();
//数字面板
private JPanel buttonsPanel = new JPanel();
//输入数据文本框
private JTextField input = new JTextField(20);
//退格键
private JButton backspace = new JButton("BackSpace");
//清空
private JButton CE = new JButton("CE ");
//删除
private JButton C = new JButton("C ");
//四则运算符号键
private JButton add = new JButton("+");
private JButton sub = new JButton("-");
private JButton mul = new JButton("*");
private JButton div = new JButton("/");
//小数点
private JButton decimal = new JButton(".");
//等号
private JButton equal = new JButton("=");
//数字键
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 = "";//保存第一个运算数字
private String operator = "";//保存运算符号
public static void main(String[] args) {
new Calculator();//new计算器实例
}
public Calculator(){
//添加组件，布局
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);
//注册各个组件监听事件
backspace.addMouseListener(new OperationMouseListener());
CE.addMouseListener(new OperationMouseListener());
C.addMouseListener(new OperationMouseListener());
decimal.addMouseListener(new OperationMouseListener());
equal.addMouseListener(new OperationMouseListener());
//注册四则运算监听
add.addMouseListener(new CalcMouseListener());
sub.addMouseListener(new CalcMouseListener());
mul.addMouseListener(new CalcMouseListener());
div.addMouseListener(new CalcMouseListener());
//注册数字监听事件
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")){//如果文本框已经是0，结果还是0
input.setText(((JButton)e.getSource()).getText().trim());
}else{//否则的话，把0添加到后面，譬如文本框是1，结果就为10
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{
//如果输入的是运算符号，保存第一个结果和运算符号
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){//退格键，删除一个直到没有字符删除
String inputText = input.getText();
if(inputText.length() > 0){
input.setText(inputText.substring(0, inputText.length() - 1));
}
}else if(e.getSource() == C){
input.setText("0");//C，清空所有运算数字和符号
num1 = "";
}else if(e.getSource() == CE){
input.setText("0");//CE-->将文本框置为0
}else if(e.getSource() == decimal){
String text = input.getText().trim();
//如果按了小数点，如果文本框已经有小数点，不做任何操作，否则在结果后面加上小数点
if(text.indexOf(".") == -1){
input.setText(text.concat("."));
}
}else if(e.getSource() == equal){
//如果是等号
if(!operator.trim().equals("")){
if(!input.getText().trim().equals("")){
double result = 0D;
if(operator.equals("+")){//执行加法运算
result = Double.parseDouble(num1) + Double.parseDouble(input.getText().trim());
}else if(operator.equals("-")){//减法运算
result = Double.parseDouble(num1) - Double.parseDouble(input.getText().trim());
}else if(operator.equals("*")){//乘法运算
result = Double.parseDouble(num1) * Double.parseDouble(input.getText().trim());
}else if(operator.equals("/")){//除法运算
result = Double.parseDouble(num1) / Double.parseDouble(input.getText().trim());
}
//格式化最终结果，保留两位小数点
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) {}
}
}
4. 用JAVA编写一个计算器
打开IED：打开自己java编程的软件，采用的是eclipse软件。
建立java工程。
编写类。
5. 如何java设计计算器并实现功能
java设计计算器，主要是使用java swing，对每个按钮进行监听，实现相关功能，如下代码：
packagecom.qiu.lin.he;
importjava.awt.BorderLayout;
importjava.awt.Color;
importjava.awt.GridLayout;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjavax.swing.ImageIcon;
importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JPanel;
importjavax.swing.JTextField;
importjavax.swing.SwingConstants;
{
/**
*
*/
=1L;
Resultresult=newResult();//定义text的面板
Number_Keynumber_key=newNumber_Key();//定义按钮面板
//当点击按钮+、-、*、/时，com=true
booleancom=false;
//当i=0时说明是我们第一次输入，字符串text不会累加
inti=0;
//存放text的内容
Stringtext="";
//存放点击按钮+、-、*、/之前的数值
doubledefbutton=0;
//+、-、*、/的代号分别为1，2，3，4
intsymbol=0;
//构造函数
Jisuanqi(){
super("WangJiao");//设定标题
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设定关闭窗体时退出程序
JPanelpane=newJPanel();//定义主面板
pane.setLayout(newBorderLayout());
setBounds(380,220,30,80);//前两个参数是在屏幕上显示的坐标，后两个是大小
//替换图标
ImageIconicon=newImageIcon("F:1.GIF");
//Jisuanqi.class.getResource("APPLE.GIF")
//);
setIconImage(icon.getImage());
pane.add(result,BorderLayout.NORTH);
pane.add(number_key,BorderLayout.CENTER);
pane.add(number_key.equal,BorderLayout.SOUTH);
number_key.one.addActionListener(this);//对1按钮添加监听事件
number_key.two.addActionListener(this);//对2按钮添加监听事件
number_key.three.addActionListener(this);//对3按钮添加监听事件
number_key.four.addActionListener(this);//对4按钮添加监听事件
number_key.five.addActionListener(this);//对5按钮添加监听事件
number_key.six.addActionListener(this);//对6按钮添加监听事件
number_key.seven.addActionListener(this);//对7按钮添加监听事件
number_key.eight.addActionListener(this);//对8按钮添加监听事件
number_key.nine.addActionListener(this);//对9按钮添加监听事件
number_key.zero.addActionListener(this);//对0按钮添加监听事件
number_key.ce.addActionListener(this);//对置零按钮添加监听事件
number_key.plus.addActionListener(this);//对+按钮添加监听事件
number_key.equal.addActionListener(this);//对=按钮添加监听事件
number_key.sub.addActionListener(this);//对-按钮添加监听事件
number_key.mul.addActionListener(this);//对*按钮添加监听事件
number_key.div.addActionListener(this);//对/按钮添加监听事件
number_key.point.addActionListener(this);//对.按钮添加监听事件
setContentPane(pane);
pack();//初始化窗体大小为正好盛放所有按钮
}
//各个按钮触发的事件
publicvoidactionPerformed(ActionEvente){
/*
*如果是点击数字按钮那么先要判断是否在此之前点击了+、-、*、/、=，如果是那么com=true如果没有com=
*false;或者是否点击数字键，如果是i=1,如果没有i=0;
*/
if(e.getSource()==number_key.one){
if(com||i==0){
result.text.setText("1");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"1");
}
}elseif(e.getSource()==number_key.two){
if(com||i==0){
result.text.setText("2");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"2");
}
}elseif(e.getSource()==number_key.three){
if(com||i==0){
result.text.setText("3");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"3");
}
}elseif(e.getSource()==number_key.four){
if(com||i==0){
result.text.setText("4");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"4");
}
}elseif(e.getSource()==number_key.five){
if(com||i==0){
result.text.setText("5");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"5");
}
}elseif(e.getSource()==number_key.six){
if(com||i==0){
result.text.setText("6");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"6");
}
}elseif(e.getSource()==number_key.seven){
if(com||i==0){
result.text.setText("7");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"7");
}
}elseif(e.getSource()==number_key.eight){
if(com||i==0){
result.text.setText("8");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"8");
}
}elseif(e.getSource()==number_key.nine){
if(com||i==0){
result.text.setText("9");
com=false;
i=1;
}else{
text=result.text.getText();
result.text.setText(text+"9");
}
}
/*
*对于0这个按钮有一定的说法，在我的程序里不会出现如00000这样的情况，我加了判断条件就是
*如果text中的数值=0就要判断在这个数值中是否有.存在?如果有那么就在原来数值基础之上添加0;否则保持原来的数值不变
*/
elseif(e.getSource()==number_key.zero){//result.text.getText()是得到text里内容的意思
if(com||i==0){
result.text.setText("0");
com=false;
i=1;
}else{
text=result.text.getText();
if(Float.parseFloat(text)>0||Float.parseFloat(text)<0){//Float.parseFloat(text)就是类型转换了，下面都是一样
result.text.setText(text+"0");
}else{
if(text.trim().indexOf(".")==-1){
result.text.setText(text);
}else{
result.text.setText(text+"0");
}
}
}
}elseif(e.getSource()==number_key.ce){
result.text.setText("0");
i=0;
com=true;
//text="";
defbutton=0;
}
/*
*本程序不会让一个数值中出现2个以上的小数点.具体做法是:判断是否已经存在.存在就不添加,不存在就添加.
*/
elseif(e.getSource()==number_key.point){
if(com||i==0){
result.text.setText("0.");
com=false;
i=1;
}else{
text=result.text.getText();
if(text.trim().indexOf(".")==-1){
result.text.setText(text+".");
}else{
result.text.setText(text);
}
}
}//获得点击+之前的数值
elseif(e.getSource()==number_key.plus){
com=true;
i=0;
defbutton=Double.parseDouble(result.text.getText());
symbol=1;
}//获得点击-之前的数值
elseif(e.getSource()==number_key.sub){
com=true;
i=0;
defbutton=Double.parseDouble(result.text.getText());
symbol=2;
}//获得点击*之前的数值
elseif(e.getSource()==number_key.mul){
com=true;
i=0;
defbutton=Double.parseDouble(result.text.getText());
System.out.println(defbutton);
symbol=3;
}//获得点击/之前的数值
elseif(e.getSource()==number_key.div){
com=true;
i=0;
defbutton=Double.parseDouble(result.text.getText());
symbol=4;
}elseif(e.getSource()==number_key.equal){
switch(symbol){
case1:{//计算加法
doublead=defbutton
+Double.parseDouble(result.text.getText());
result.text.setText(ad+"");
i=0;
text="";
break;
}
case2:{//计算减法
doublead=defbutton
-Double.parseDouble(result.text.getText());
result.text.setText(String.valueOf(ad));
i=0;
text="";
break;
}
case3:{//计算乘法
doublead=defbutton
*Double.parseDouble(result.text.getText());
result.text.setText(ad+"");
i=0;
text="";
break;
}
case4:{//计算除法
doublead=defbutton
/Double.parseDouble(result.text.getText());
result.text.setText(ad+"");
i=0;
text="";
break;
}
}
System.out.println(com);
}
System.out.println(result.text.getText());
}
@SuppressWarnings("deprecation")
publicstaticvoidmain(String[]args){
Jisuanqiloveyou=newJisuanqi();
loveyou.show();
}
}
//计算器数字按钮定义面板
classNumber_KeyextendsJPanel{
/**
*
*/
=1L;
JButtonzero=newJButton("0");//数字键0
JButtonone=newJButton("1");//数字键1
JButtontwo=newJButton("2");//数字键2
JButtonthree=newJButton("3");//数字键3
JButtonfour=newJButton("4");//数字键4
JButtonfive=newJButton("5");//数字键5
JButtonsix=newJButton("6");//数字键6
JButtonseven=newJButton("7");//数字键7
JButtoneight=newJButton("8");//数字键8
JButtonnine=newJButton("9");//数字键9
JButtonplus=newJButton("+");
JButtonsub=newJButton("-");
JButtonmul=newJButton("*");
JButtondiv=newJButton("/");
JButtonequal=newJButton("=");
JButtonce=newJButton("清零");//置零键
JButtonpoint=newJButton(".");
Number_Key(){
setLayout(newGridLayout(4,4,1,1));//定义布局管理器为网格布局
setBackground(Color.blue);//设置背景颜色
//添加按钮
add(one);
add(two);
add(three);
add(four);
add(five);
add(six);
add(seven);
add(eight);
add(nine);
add(zero);
add(plus);
add(sub);
add(mul);
add(div);
add(point);
add(equal);
add(ce);
}
}
//计算器显示结果的窗体
classResultextendsJPanel{
/**
*
*/
=1L;
//text先是输入和结果
JTextFieldtext=newJTextField("0");
@SuppressWarnings("deprecation")
Result(){//讲输入的数字或得到的结果在text的右边显示
text.setHorizontalAlignment(SwingConstants.RIGHT);
text.enable(false);//文本框不能编辑
setLayout(newBorderLayout());//设定布局管理器边框布局
add(text,BorderLayout.CENTER);//text放置在窗体的中间
}
}
运行结果如下：
6. Java设计计算器
****************************************************************
写了一天，终于写完了。
****************************************************************
说明：
类Calc.java出了界面符合你的要求外，还有以下优点：
1.对输入内容进行校验，如果是非法字符（如字母），不响应键盘事件，而且单个文本框只能输入一个小数点；
2.使用Windows界面风格；
3.采用大数计算，更精准；
4.其它……
****************************************************************
代码如下：
****************************************************************
importjava.awt.BorderLayout;
importjava.awt.Dimension;
importjava.awt.FlowLayout;
importjava.awt.Toolkit;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.awt.event.KeyAdapter;
importjava.awt.event.KeyEvent;
importjava.math.BigDecimal;
importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JLabel;
importjavax.swing.JMenu;
importjavax.swing.JMenuBar;
importjavax.swing.JMenuItem;
importjavax.swing.JOptionPane;
importjavax.swing.JPanel;
importjavax.swing.JTextField;
importjavax.swing.UIManager;
/**
*@authorGodwin
*@version2010-05-16
*/
{
JTextFieldnumber1Text;
JTextFieldnumber2Text;
JTextFieldresultText;
publicCalc(){
this.setTitle("计算器");
/*
*菜单栏
*/
//Operation菜单
JMenuItemaddMenuItem=newJMenuItem("Add");
addMenuItem.setMnemonic('a');
JMenuItemsubtractMenuItem=newJMenuItem("Subtract");
subtractMenuItem.setMnemonic('s');
JMenuItemmultiplyMenuItem=newJMenuItem("Multiply");
multiplyMenuItem.setMnemonic('m');
JMenuItemdivideMenuItem=newJMenuItem("Divide");
divideMenuItem.setMnemonic('d');
JMenuoperationFile=newJMenu("Operation");
operationFile.setMnemonic('o');
operationFile.add(addMenuItem);
operationFile.add(subtractMenuItem);
operationFile.add(multiplyMenuItem);
operationFile.add(divideMenuItem);
//Exit菜单
JMenuexitMenu=newJMenu("Exit");
exitMenu.setMnemonic('x');
JMenuItemexitItem=newJMenuItem("Exit");
exitItem.setMnemonic('x');
exitItem.addActionListener(newExitActionListener());
exitMenu.add(exitItem);
//添加Operation和Exit菜单
JMenuBarmenubar=newJMenuBar();
menubar.add(operationFile);
menubar.add(exitMenu);
/*
*操作数和结果
*/
JLabelnumber1Label=newJLabel("Number1");
number1Text=newJTextField(6);
JLabelnumber2Label=newJLabel("Number2");
number2Text=newJTextField(6);
JLabelresultLabel=newJLabel("Result");
resultText=newJTextField(10);
resultText.setEditable(false);
JPaneloperandPanel=newJPanel(newFlowLayout());
operandPanel.add(number1Label);
operandPanel.add(number1Text);
operandPanel.add(number2Label);
operandPanel.add(number2Text);
operandPanel.add(resultLabel);
operandPanel.add(resultText);
/*
*操作符
*/
JButtonaddButton=newJButton("Add");
JButtonsubtractButton=newJButton("Subtract");
JButtonmultiplyButton=newJButton("Multiply");
JButtondivideButton=newJButton("Divide");
JPaneloperatorPanel=newJPanel(newFlowLayout());
operatorPanel.add(addButton);
operatorPanel.add(subtractButton);
operatorPanel.add(multiplyButton);
operatorPanel.add(divideButton);
/*
*添加所有面板
*/
this.add(menubar,BorderLayout.NORTH);
this.add(operandPanel,BorderLayout.CENTER);
this.add(operatorPanel,BorderLayout.SOUTH);
this.pack();
this.setResizable(false);
Toolkittool=Toolkit.getDefaultToolkit();
Dimensionscreen=tool.getScreenSize();
this.setLocation(screen.width/2-this.getWidth()/2,screen.height
/2-this.getHeight()/2);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
/*
*添加事件监听
*/
//菜单监听
addMenuItem.addActionListener(this);
subtractMenuItem.addActionListener(this);
multiplyMenuItem.addActionListener(this);
divideMenuItem.addActionListener(this);
//文本框监听
number1Text.addKeyListener(newVerifyInputKeyAdapter());
number2Text.addKeyListener(newVerifyInputKeyAdapter());
//按钮监听
addButton.addActionListener(this);
subtractButton.addActionListener(this);
multiplyButton.addActionListener(this);
divideButton.addActionListener(this);
}
{
publicvoidkeyTyped(KeyEvente){
charc=e.getKeyChar();
System.out.println(c);
if(!(('0'<=c)&&(c<='9')||(c==KeyEvent.VK_DELETE)||(c==KeyEvent.VK_BACK_SPACE))){
if(!((!((JTextField)(e.getSource())).getText().contains("."))&&(c=='.'))){
e.consume();
}
}
}
}
{
publicvoidactionPerformed(ActionEvente){
System.exit(0);
}
}
publicvoidactionPerformed(ActionEvente){
Stringoperand1=number1Text.getText();
BigDecimalbig1=BigDecimal.valueOf(Double.valueOf(operand1));
Stringoperand2=number2Text.getText();
BigDecimalbig2=BigDecimal.valueOf(Double.valueOf(operand2));
if((!(operand1.equals("")))&&(operand1!=null)
&&(!(operand2.equals("")))&&(operand2!=null)){
Stringname=e.getSource().getClass().getSimpleName();
Stringoperator="";
if(name.equals("JButton")){
JButtonb=(JButton)(e.getSource());
operator=b.getText();
}elseif(name.equals("JMenuItem")){
JMenuItemm=(JMenuItem)e.getSource();
operator=m.getText();
}
if(operator.equals("Add")){
resultText.setText(String.valueOf(big1.add(big2)));
}elseif(operator.equals("Subtract")){
resultText.setText(String.valueOf(big1.subtract(big2)));
}elseif(operator.equals("Multiply")){
resultText.setText(String.valueOf(big1.multiply(big2)));
}elseif(operator.equals("Divide")){
resultText.setText(String.valueOf(big1.divide(big2)));
}else{
JOptionPane.showMessageDialog(this,"操作有误！","错误提示",
JOptionPane.WARNING_MESSAGE);
}
}else{
JOptionPane.showMessageDialog(this,"请输入操作数！","错误提示",
JOptionPane.WARNING_MESSAGE);
number1Text.requestFocus();
}
}
publicstaticvoidmain(String[]args)throwsException{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
newCalc();
}
}
****************************************************************
运行结果如下：
7. JAVA设计计算器
packagecn.hnpi;
importjava.awt.BorderLayout;
importjava.awt.GridLayout;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JPanel;
importjavax.swing.JTextField;
{
JButtonb0=newJButton("0");
JButtonb1=newJButton("1");
JButtonb2=newJButton("2");
JButtonb3=newJButton("3");
JButtonb4=newJButton("4");
JButtonb5=newJButton("5");
JButtonb6=newJButton("6");
JButtonb7=newJButton("7");
JButtonb8=newJButton("8");
JButtonb9=newJButton("9");
JButtonjiaButton=newJButton("+");
JButtonjianButton=newJButton("-");
JButtonchengButton=newJButton("*");
JButtonchuButton=newJButton("/");
JButtonyuButton=newJButton("%");
JButtonjjButton=newJButton("+/-");
JButtonsqrtButton=newJButton("sqrt");
JButtondianButton=newJButton(".");
JButtondengButton=newJButton("=");
JButtonButton=newJButton("1/x");
JButtonbackButton=newJButton("Backpace");
JButtoncButton=newJButton("C");
publicdoubleop1;
publicdoubleop2;
publicstaticfinalintJIA=0;
publicstaticfinalintJIAN=1;
publicstaticfinalintCHENG=2;
publicstaticfinalintCHU=3;
publicstaticfinalintJJ=4;
publicstaticfinalintDIAN=5;
publicintcurrent0p=0;
privatebooleanopEnd=false;
JPanelpanel1=newJPanel();
JPanelpanel2=newJPanel();
JPanelpanel3=newJPanel();
JPanelpanel4=newJPanel();
JTextFieldresult=newJTextField(20);
publicCalculator(){
initPanel2();
initPanel3();
panel2.setLayout(newGridLayout(5,4));
panel1.setLayout(newBorderLayout());
panel1.add(panel3,BorderLayout.NORTH);//设置位置
panel1.add(panel2,BorderLayout.CENTER);//设置位置
getContentPane().add(panel1);
addActionListeners();
setSize(260,260);
setLocation(500,300);
setVisible(true);
setDefaultCloseOperation(Calculator.EXIT_ON_CLOSE);
this.setResizable(false);
this.setTitle("计算器");
}
privatevoidinitPanel2(){
//把组件添加到相应的panel上
panel2.add(b7);
panel2.add(b8);
panel2.add(b9);
panel2.add(chuButton);
panel2.add(b4);
panel2.add(b5);
panel2.add(b6);
panel2.add(chengButton);
panel2.add(b1);
panel2.add(b2);
panel2.add(b3);
panel2.add(jianButton);
panel2.add(b0);
panel2.add(jjButton);
panel2.add(dianButton);
panel2.add(jiaButton);
panel2.add(Button);
panel2.add(yuButton);
panel2.add(sqrtButton);
panel2.add(dengButton);
}
privatevoidaddActionListeners(){
ActionHandlerc=newActionHandler();
b0.addActionListener(c);
b1.addActionListener(c);
b2.addActionListener(c);
b3.addActionListener(c);
b4.addActionListener(c);
b5.addActionListener(c);
b6.addActionListener(c);
b7.addActionListener(c);
b8.addActionListener(c);
b9.addActionListener(c);
jiaButton.addActionListener(c);
dengButton.addActionListener(c);
chengButton.addActionListener(c);
chuButton.addActionListener(c);
jianButton.addActionListener(c);
jjButton.addActionListener(c);
dianButton.addActionListener(c);
sqrtButton.addActionListener(c);
yuButton.addActionListener(c);
Button.addActionListener(c);
backButton.addActionListener(c);
cButton.addActionListener(c);
}
{
publicvoidactionPerformed(ActionEvente){
if(e.getSource()==b0){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"0");
}
if(e.getSource()==b1){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"1");
opEnd=true;
}
if(e.getSource()==b2){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"2");
opEnd=true;
}
if(e.getSource()==b3){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"3");
opEnd=true;
}
if(e.getSource()==b4){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"4");
opEnd=true;
}
if(e.getSource()==b5){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"5");
opEnd=true;
}
if(e.getSource()==b6){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"6");
opEnd=true;
}
if(e.getSource()==b7){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"7");
opEnd=true;
}
if(e.getSource()==b8){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"8");
opEnd=true;
}
if(e.getSource()==b9){
if(opEnd==false){
result.setText("");
}
result.setText(result.getText()+"9");
opEnd=true;
}
try{
if(e.getSource()==jiaButton){
op1=Double.parseDouble(result.getText());
//2、说明操作数已经输入完毕
opEnd=false;
current0p=JIA;
}
if(e.getSource()==chengButton){
op1=Double.parseDouble(result.getText());
//2、说明操作数已经输入完毕
opEnd=false;
current0p=CHENG;
}
if(e.getSource()==chuButton){
op1=Double.parseDouble(result.getText());
//2、说明操作数已经输入完毕
opEnd=false;
current0p=CHU;
}
if(e.getSource()==jianButton){
op1=Double.parseDouble(result.getText());
//2、说明操作数已经输入完毕
opEnd=false;
current0p=JIAN;
}
if(e.getSource()==jjButton){
Stringtmp=result.getText();
if(tmp.equals("")||tmp.equals("0")){
return;
}
if(tmp.charAt(0)=='-'){
tmp=tmp.substring(1);
}else{
tmp='-'+tmp;
}
result.setText(tmp);
}
if(e.getSource()==dianButton){
Stringtmp=result.getText();
if(tmp.equals("")){
return;
}
if(tmp.indexOf(".")!=-1){
return;
}
tmp=tmp+".";
result.setText(tmp);
}
if(e.getSource()==sqrtButton){
Stringtmp=result.getText();
if(tmp.equals("")){
return;
}
doubled;
d=Double.parseDouble(tmp);//先定义一个double类型的d
if(d<0){
result.setText("不能对负数求平方根！");
return;
}
op2=Math.sqrt(d);
result.setText(op2+"");
}
if(e.getSource()==backButton){
Strings=result.getText();
result.setText("");
for(inti=0;i<s.length()-1;i++){
chara=s.charAt(i);
result.setText(result.getText()+a);
}
}
if(e.getSource()==cButton){
result.setText("0");
opEnd=false;
}
if(e.getSource()==dengButton){
op2=Double.parseDouble(result.getText());
switch(current0p){
caseJIA:
result.setText(op1+op2+"");
break;
caseJIAN:
result.setText(op1-op2+"");
break;
caseCHENG:
result.setText(op1*op2+"");
break;
caseCHU:
if(op2==0){
result.setText("被除数不能为零！");
break;
}
result.setText(op1/op2+"");
break;
}
opEnd=false;
}
}catch(Exceptione1){
result.setText("Wrong");
opEnd=false;
}
}
}
privatevoidinitPanel3(){
panel3.setLayout(newGridLayout(2,1));
panel3.add(result);
panel3.add(panel4);
panel4.setLayout(newGridLayout(1,2));
panel4.add(backButton);
panel4.add(cButton);
//panel3.setPreferredSize(newDimension(260,65));
}
publicstaticvoidmain(String[]args){
Calculatorc=newCalculator();//生成类的实例
}
}
8. java设计个简单计算器
packagezhang16;
importjava.awt.*;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.text.DecimalFormat;
importjavax.swing.*;
importjavax.swing.border.Border;
importjavax.swing.border.LineBorder;
publicclass简单计算器16_4extendsJFrame{
privatedoublenum1,num2,res;
privateJTextFieldnumber1=newJTextField(5);
privateJTextFieldnumber2=newJTextField(5);
privateJTextFieldresult=newJTextField(10);
JButtonjia=newJButton("jia");
JButtonjian=newJButton("jian");
JButtoncheng=newJButton("cheng");
JButtonchu=newJButton("chu");
public简单计算器16_4(){
//TODOAuto-generatedconstructorstub
JPanelp1=newJPanel();
JPanelp2=newJPanel();
setLayout(newGridLayout(2,1));
this.add(p1,newFlowLayout());
p1.add(newJLabel("num1"));
p1.add(number1);
p1.add(newJLabel("num"));
p1.add(number2);
p1.add(newJLabel("result"));
p1.add(result);
Borderb=newLineBorder(Color.black,1);
this.add(p2,newFlowLayout());
p2.add(jia);
p2.add(jian);
p2.add(cheng);
p2.add(chu);
p1.setBorder(b);
p2.setBorder(b);
ButtonListenerActionListener=newButtonListener();
jia.addActionListener(ActionListener);
jian.addActionListener(ActionListener);
cheng.addActionListener(ActionListener);
chu.addActionListener(ActionListener);
}
{
@Override
publicvoidactionPerformed(ActionEvente){
//TODOAuto-generatedmethodstub
DecimalFormatdf=newDecimalFormat("0.00");
if(e.getSource()==jia){
Stringnum11=number1.getText();
num1=Double.parseDouble(num11);
Stringnum22=number2.getText();
num2=Double.parseDouble(num22);
res=num1+num2;
result.setText(df.format(res)+"");
}elseif(e.getSource()==jian){
Stringnum11=number1.getText();
num1=Double.parseDouble(num11);
Stringnum22=number2.getText();
num2=Double.parseDouble(num22);
res=num1-num2;
result.setText(df.format(res)+"");
}elseif(e.getSource()==cheng){
Stringnum11=number1.getText();
num1=Double.parseDouble(num11);
Stringnum22=number2.getText();
num2=Double.parseDouble(num22);
res=num1*num2;
result.setText(df.format(res)+"");
}elseif(e.getSource()==chu){
Stringnum11=number1.getText();
num1=Double.parseDouble(num11);
Stringnum22=number2.getText();
num2=Double.parseDouble(num22);
res=num1/num2;
result.setText(df.format(res)+"");
}
}
}
publicstaticvoidmain(String[]args){
//TODOAuto-generatedmethodstub
JFramef=new简单计算器16_4();
f.setSize(400,130);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLocationRelativeTo(null);
}
}
9. 用JAVA编写一个简单的计算器，要求如下
太麻烦了 说个思路, 过去字符串后 先获取+-*%的下标.然后然后分割,获取到一个数组或list
然后循环获取() 按照数学运算顺序拼起来,
然后把公式拆分一步一步操作就得出结果啦
10. 用JAVA编写一个简单计算器界面做出来了。
import sun.plugin.security.Broken11ClassFixer;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JFrame;
import java.awt.FlowLayout;
import javax.swing.JButton;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Scanner;
public class Test extends JFrame{
private JTextField t1;
private JTextField t2;
private JTextField t3;
private JButton b1;
public Test(){
p1=new JPanel();
JPanel p2=new JPanel();
p1.setLayout(new FlowLayout(FlowLayout.LEFT,4,3));
t1 = new JTextField("0",4);
t2 = new JTextField("0",4);
t3 = new JTextField(8);
b1 = new JButton("=");
p1.add(t1);
p1.add(new JTextField(" + "));
p1.add(t2);
p1.add(new JLabel("="));
p1.add(t3);
p2.add(b1,BorderLayout.CENTER);
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
t3.setText(Integer.toString(Integer.parseInt(t1.getText())+Integer.parseInt(t2.getText())));
}
});
add(p1,BorderLayout.NORTH);
add(p2,BorderLayout.SOUTH);
}
public static void main(String[] args){
Test frame=new Test();
frame.setTitle("计算器");
frame.setSize(300,100);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
帮你完善了下，其他来不及写了都是一样的，稍微改一下就行