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JAVA计算器实验代码 基于java的计算器实现代码
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用JAVA编写一个简单的计算器，要求如下:
然后 通过输入 显示结果，比如说：
以下是上图计算器JAVA计算器实验代码的代码:
package Computer;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Stack;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Count extends JApplet implements ActionListener
{
/**
*
*/
private static final long serialVersionUID = 1L;
private JTextField textField = new JTextField("请输入");
String operator = "";//操作
String input = "";//输入的 式子
boolean flag = true;
// boolean flag1 = true;
// boolean flag2 = true;
public void init()//覆写Applet里边的init方法
{
Container C = getContentPane();
JButton b[] = new JButton[16];
JPanel panel = new JPanel();
C.add(textField, BorderLayout.NORTH);
C.add(panel,BorderLayout.CENTER);
panel.setLayout(new GridLayout(4, 4,5,5));
String name[]={"7","8","9","+","4","5","6","-","1","2","3","*","0","C","=","/"};//设置 按钮
for(int i=0;i16;i++)//添加按钮
{
b[i] = new JButton(name[i]);
b[i].setBackground(new Color(192,192,192));
b[i].setForeground(Color.BLUE);//数字键 设置为 蓝颜色
if(i%4==3)
b[i].setForeground(Color.RED);
b[i].setFont(new Font("宋体",Font.PLAIN,16));//设置字体格式
panel.add(b[i]);
b[i].addActionListener(this);
}
b[13].setForeground(Color.RED);//非数字键，即运算键设置为红颜色
b[13].setForeground(Color.RED);
}
public void actionPerformed(ActionEvent e)
{
int cnt = 0;
String actionCommand = e.getActionCommand();
if(actionCommand.equals("+")||actionCommand.equals("-")||actionCommand.equals("*") ||actionCommand.equals("/"))
input +=" "+actionCommand+" ";//设置输入，把输入的样式改成 需要的样子
else if(actionCommand.equals("C"))
input = "";
else if(actionCommand.equals("="))//当监听到等号时，则处理 input
{
input+= "="+compute(input);
textField.setText(input);
input="";
cnt = 1;
}
else
input += actionCommand;//数字为JAVA计算器实验代码了避免多位数的输入 不需要加空格
if(cnt==0)
textField.setText(input);
}
private String compute(String input)//即1237 的 样例
{
String str[];
str = input.split(" ");
StackDouble s = new StackDouble();
double m = Double.parseDouble(str[0]);
s.push(m);
for(int i=1;istr.length;i++)
{
if(i%2==1)
{
if(str[i].compareTo("+")==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(help);
}
if(str[i].compareTo("-")==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(-help);
}
if(str[i].compareTo("*")==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();//取出栈顶元素
s.pop();//消栈
ans*=help;
s.push(ans);
}
if(str[i].compareTo("/")==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();
s.pop();
ans/=help;
s.push(ans);
}
}
}
double ans = 0d;
while(!s.isEmpty())
{
ans+=s.peek();
s.pop();
}
String result = String.valueOf(ans);
return result;
}
public static void main(String args[])
{
JFrame frame = new JFrame("Count");
Count applet = new Count();
frame.getContentPane().add(applet, BorderLayout.CENTER);
applet.init();//applet的init方法
applet.start();//线程开始
frame.setSize(350, 400);//设置窗口大小
frame.setVisible(true);//设置窗口可见
}
}
相关问答
Q1: java编一个计算器的代码
界面漂亮堪比系统自带计算器JAVA计算器实验代码，功能完美加减乘除开平方等等全部具备JAVA计算器实验代码，还有清零按钮，小数点JAVA计算器实验代码的使用，连加连乘功能完全参考系统官方计算器经过长期调试改进而成，马上拷贝代码拿去试试看吧，绝不后悔！
代码如下：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Counter {
public static void main(String[] args) {
CounterFrame frame = new CounterFrame();
frame.show();
}
}
class CounterFrame extends JFrame {
public CounterFrame() {
JMenuBar menuBar = new JMenuBar();
JMenu menuFile = new JMenu();
JMenu menuFile1 = new JMenu();
JMenu menuFile2 = new JMenu();
JMenu menuFile3 = new JMenu();
JMenuItem menuFileExit = new JMenuItem();
menuFile.setText("文件");
menuFile1.setText("编辑");
menuFile2.setText("查看");
menuFile3.setText("帮助");
menuFileExit.setText("退出");
menuFileExit.addActionListener
(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
CounterFrame.this.windowClosed();
}
}
);
menuFile.add(menuFileExit);
menuBar.add(menuFile);
menuBar.add(menuFile1);
menuBar.add(menuFile2);
menuBar.add(menuFile3);
setTitle("计算器");
setJMenuBar(menuBar);
setSize(new Dimension(400, 280));
this.getContentPane().add(new Allpanel());
this.addWindowListener
(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
CounterFrame.this.windowClosed();
}
}
);
}
protected void windowClosed() {
System.exit(0);
}
}
class Tool {
public static Tool instance;
private JTextField field;
private Tool() {
this.field=new JTextField(30);
this.field.setHorizontalAlignment(JTextField.RIGHT);
}
public static Tool getinstance()
{
if(instance==null)
{
instance=new Tool();
}
return instance;
}
public JTextField getfield()
{
return (this.field);
}
}
class Allpanel extends JPanel {
public Allpanel() {
this.setLayout(new BorderLayout(0,7));
Northpanel np=new Northpanel();
Centerpanel cp=new Centerpanel();
this.add(np,BorderLayout.NORTH);
this.add(cp,BorderLayout.CENTER);
}
}
class Centercenter extends JPanel {
static Vector Vec=new Vector();
static Vector vc=new Vector();
static Vector vc1=new Vector();
static Vector vc2=new Vector();
static Vector vc3=new Vector();
static String begin="yes";
static double add;
static double jq;
static double cs;
static double cq;
static double dy;
static String jg;
static String what;
static double tool=0;
static String to="yes";
/**
* Method Centercenter
*
*
*/
public Centercenter() {
// TODO: Add your code here
final JTextField text=Tool.getinstance().getfield();
this.setLayout(new GridLayout(4,5,3,3));
String arg[] ={"7","8","9","/","sqrt","4","5","6","*","%","1","2","3","-","1/x","0","+/-",".","+","="};
for(int i=0;i20;i++)
{
final JButton b=new JButton(arg[i]);
//this.add(new JButton(arg[i]));
this.add(b);
if(i==0||i==1||i==2||i==5||i==6||i==7||i==10||i==11||i==12||i==15)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String mark=b.getText();
String ma=text.getText();
if(vc3.contains("v3"))
{
text.setText("0."+mark);
vc3.clear();
}
else if(vc.contains("a"))
{
if(vc2.contains("v2"))
{
text.setText("0."+mark);
vc.clear();
vc2.clear();
}
else
{
text.setText(mark);
vc.clear();
Vec.clear();
Vec.add(mark);
}
}
else
{
text.setText(ma.trim()+mark);
Vec.add(mark);
}
begin="no";
to="yes";
}
});
}
if(i==17)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String mar=b.getText();
String m=text.getText();
if("yes".equals(begin))
{
vc3.add("v3");
}
if(vc1.contains("v1"))
{
vc2.add("v2");
vc1.clear();
}
if(!Vec.contains(".")!vc.contains("a"))
{
text.setText(m.trim()+mar);
Vec.add(".");
}
}
});
}
if(i==18)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
add=Double.parseDouble(ma);
if(what==null)
{
tool=add;
what="add";
}
else
{
tool=tool+add;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="+";
}
});
}
if(i==13)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
jq=Double.parseDouble(ma);
if(what==null)
{
tool=jq;
what="jq";
}
else
{
tool=tool-jq;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="-";
}
});
}
if(i==3)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
cq=Double.parseDouble(ma);
if(what==null)
{
tool=cq;
what="cq";
}
else
{
tool=tool/cq;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="/";
}
});
}
if(i==4)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
cq=Double.parseDouble(ma);
text.setText(String.valueOf(Math.sqrt(cq)));
}
});
}
if(i==8)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
cs=Double.parseDouble(ma);
if(what==null)
{
tool=cs;
what="cs";
}
else
{
tool=tool*cs;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="*";
}
});
}
if(i==19)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
dy=Double.parseDouble(ma);
if(what=="add")
{
jg=String.valueOf((tool+dy));
}
if(what=="jq")
{
jg=String.valueOf((tool-dy));
}
if(what=="cs")
{
jg=String.valueOf((tool*dy));
}
if(what=="cq")
{
jg=String.valueOf((tool/dy));
}
if(what==null)
{
if(to=="+")
{
tool=add;
jg=String.valueOf(tool+dy);
}
else if(to=="-")
{
tool=jq;
jg=String.valueOf(dy-tool);
}
else if(to=="*")
{
tool=cs;
jg=String.valueOf(dy*tool);
}
else if(to=="/")
{
tool=cq;
jg=String.valueOf(dy/tool);
}
else
{
jg=String.valueOf(dy);
}
}
text.setText(jg);
Vec.clear();
Vec.add(".");
vc.add("a");
vc1.add("v1");
what=null;
tool=0;
}
});
}
}
}
}
class Centernorth extends JPanel {
public Centernorth() {
final JTextField text=Tool.getinstance().getfield();
JButton jb1=new JButton("Backspace");
JButton jb2=new JButton(" CE ");
JButton jb3=new JButton(" C ");
this.add(jb1);
this.add(jb2);
this.add(jb3);
jb1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
String back=Tool.getinstance().getfield().getText();
text.setText(backmethod(back));
Centercenter.Vec.remove(Centercenter.Vec.size()-1);
}
});
jb3.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
text.setText("0.");
Centercenter.Vec.clear();
Centercenter.Vec.add(".");
Centercenter.vc.add("a");
Centercenter.begin="yes";
Centercenter.vc1.clear();
Centercenter.what=null;
Centercenter.tool=0;
}
});
}
public String backmethod(String str)
{
return str.substring(0,str.length()-1);
}
}
class Centerpanel extends JPanel {
public Centerpanel() {
this.setLayout(new BorderLayout(8,7));
Centernorth cn=new Centernorth();
Centercenter cc=new Centercenter();
Centerwest cw=new Centerwest();
this.add(cn,BorderLayout.NORTH);
this.add(cc,BorderLayout.CENTER);
this.add(cw,BorderLayout.WEST);
}
}
class Centerwest extends JPanel {
public Centerwest() {
this.setLayout(new GridLayout(4,1,3,3));
this.add(new JButton("MC"));
this.add(new JButton("MR"));
this.add(new JButton("MS"));
this.add(new JButton("M+"));
}
}
class Northpanel extends JPanel {
private JTextField tf;
public Northpanel() {
tf=Tool.getinstance().getfield();
this.add(tf);
}
}
---------------------------------------------------------------------------
=============《按你要求特意后改过的最简单功能的代码如下》========================
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Counter2 {
public static void main(String[] args) {
CounterFrame frame = new CounterFrame();
frame.show();
}
}
class CounterFrame extends JFrame {
public CounterFrame() {
setTitle("计算器");
setSize(new Dimension(400, 280));
this.getContentPane().add(new Allpanel());
this.addWindowListener
(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
CounterFrame.this.windowClosed();
}
}
);
}
protected void windowClosed() {
System.exit(0);
}
}
class Tool {
public static Tool instance;
private JTextField field;
private Tool() {
this.field=new JTextField(30);
this.field.setHorizontalAlignment(JTextField.RIGHT);
}
public static Tool getinstance()
{
if(instance==null)
{
instance=new Tool();
}
return instance;
}
public JTextField getfield()
{
return (this.field);
}
}
class Allpanel extends JPanel {
public Allpanel() {
this.setLayout(new BorderLayout(0,7));
Northpanel np=new Northpanel();
Centerpanel cp=new Centerpanel();
this.add(np,BorderLayout.NORTH);
this.add(cp,BorderLayout.CENTER);
}
}
class Centercenter extends JPanel {
static Vector Vec=new Vector();
static Vector vc=new Vector();
static Vector vc1=new Vector();
static Vector vc2=new Vector();
static Vector vc3=new Vector();
static String begin="yes";
static double add;
static double jq;
static double cs;
static double cq;
static double dy;
static String jg;
static String what;
static double tool=0;
static String to="yes";
/**
* Method Centercenter
*
*
*/
public Centercenter() {
// TODO: Add your code here
final JTextField text=Tool.getinstance().getfield();
this.setLayout(new GridLayout(4,5,3,3));
String arg[] ={"7","8","9","/","4","5","6","*","1","2","3","-","0","=",".","+"};
for(int i=0;i16;i++)
{
final JButton b=new JButton(arg[i]);
//this.add(new JButton(arg[i]));
this.add(b);
if(i==0||i==1||i==2||i==4||i==5||i==6||i==8||i==9||i==10||i==12)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String mark=b.getText();
String ma=text.getText();
if(vc3.contains("v3"))
{
text.setText("0."+mark);
vc3.clear();
}
else if(vc.contains("a"))
{
if(vc2.contains("v2"))
{
text.setText("0."+mark);
vc.clear();
vc2.clear();
}
else
{
text.setText(mark);
vc.clear();
Vec.clear();
Vec.add(mark);
}
}
else
{
text.setText(ma.trim()+mark);
Vec.add(mark);
}
begin="no";
to="yes";
}
});
}
if(i==14)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String mar=b.getText();
String m=text.getText();
if("yes".equals(begin))
{
vc3.add("v3");
}
if(vc1.contains("v1"))
{
vc2.add("v2");
vc1.clear();
}
if(!Vec.contains(".")!vc.contains("a"))
{
text.setText(m.trim()+mar);
Vec.add(".");
}
}
});
}
if(i==15)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
add=Double.parseDouble(ma);
if(what==null)
{
tool=add;
what="add";
}
else
{
tool=tool+add;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="+";
}
});
}
if(i==11)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
jq=Double.parseDouble(ma);
if(what==null)
{
tool=jq;
what="jq";
}
else
{
tool=tool-jq;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="-";
}
});
}
if(i==3)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
cq=Double.parseDouble(ma);
if(what==null)
{
tool=cq;
what="cq";
}
else
{
tool=tool/cq;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="/";
}
});
}
if(i==7)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
cs=Double.parseDouble(ma);
if(what==null)
{
tool=cs;
what="cs";
}
else
{
tool=tool*cs;
text.setText(String.valueOf((tool)));
}
vc.add("a");
vc1.add("v1");
to="*";
}
});
}
if(i==13)
{
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String ma=text.getText();
dy=Double.parseDouble(ma);
if(what=="add")
{
jg=String.valueOf((tool+dy));
}
if(what=="jq")
{
jg=String.valueOf((tool-dy));
}
if(what=="cs")
{
jg=String.valueOf((tool*dy));
}
if(what=="cq")
{
jg=String.valueOf((tool/dy));
}
if(what==null)
{
if(to=="+")
{
tool=add;
jg=String.valueOf(tool+dy);
}
else if(to=="-")
{
tool=jq;
jg=String.valueOf(dy-tool);
}
else if(to=="*")
{
tool=cs;
jg=String.valueOf(dy*tool);
}
else if(to=="/")
{
tool=cq;
jg=String.valueOf(dy/tool);
}
else
{
jg=String.valueOf(dy);
}
}
text.setText(jg);
Vec.clear();
Vec.add(".");
vc.add("a");
vc1.add("v1");
what=null;
tool=0;
}
});
}
}
}
}
class Centernorth extends JPanel {
public Centernorth() {
final JTextField text=Tool.getinstance().getfield();
}
}
class Centerpanel extends JPanel {
public Centerpanel() {
this.setLayout(new BorderLayout(8,7));
Centernorth cn=new Centernorth();
Centercenter cc=new Centercenter();
Centerwest cw=new Centerwest();
this.add(cn,BorderLayout.NORTH);
this.add(cc,BorderLayout.CENTER);
this.add(cw,BorderLayout.WEST);
}
}
class Centerwest extends JPanel {
public Centerwest() {
}
}
class Northpanel extends JPanel {
private JTextField tf;
public Northpanel() {
tf=Tool.getinstance().getfield();
this.add(tf);
}
}
------------------------------------------------------------
才子_辉祝您愉快！
Q2: java 计算器代码
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.HashMap;
/**
* 我的计算器。Cheshi 继承于 JFrame，是计算器的界面
c*/
public class Cheshi extends JFrame {
private Border border = BorderFactory.createEmptyBorder(5, 5, 5, 5);
private JTextField textbox = new JTextField("0");
private CalculatorCore core = new CalculatorCore();
private ActionListener listener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton b = (JButton) e.getSource();
String label = b.getText();
String result = core.process(label);
textbox.setText(result);
}
};
public Cheshi(String title) throws HeadlessException {
super(title); // 调用父类构造方法
setupFrame(); // 调整窗体属性
setupControls(); // 创建控件
}
private void setupControls() {
setupDisplayPanel(); // 创建文本面板
setupButtonsPanel(); // 创建按钮面板
}
// 创建按钮面板并添加按钮
private void setupButtonsPanel() {
JPanel panel = new JPanel();
panel.setBorder(border);
panel.setLayout(new GridLayout(4, 5, 3, 3));
createButtons(panel, new String[]{
"7", "8", "9", "+", "C",
"4", "5", "6", "-", "CE",
"1", "2", "3", "*", "", // 空字符串表示这个位置没有按钮
"0", ".", "=", "/", ""
});
this.add(panel, BorderLayout.CENTER);
}
/**
* 在指定的面板上创建按钮
*
* @param panel 要创建按钮的面板
* @param labels 按钮文字
*/
private void createButtons(JPanel panel, String[] labels) {
for (String label : labels) {
// 如果 label 为空，则表示创建一个空面板。否则创建一个按钮。
if (label.equals("")) {
panel.add(new JPanel());
} else {
JButton b = new JButton(label);
b.addActionListener(listener); // 为按钮添加侦听器
panel.add(b);
}
}
}
// 设置显示面板，用一个文本框来作为计算器的显示部分。
private void setupDisplayPanel() {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.setBorder(border);
setupTextbox();
panel.add(textbox, BorderLayout.CENTER);
this.add(panel, BorderLayout.NORTH);
}
// 调整文本框
private void setupTextbox() {
textbox.setHorizontalAlignment(JTextField.RIGHT); // 文本右对齐
textbox.setEditable(false); // 文本框只读
textbox.setBackground(Color.white); // 文本框背景色为白色
}
// 调整窗体
private void setupFrame() {
this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 当窗体关闭时程序结束
this.setLocation(100, 50); // 设置窗体显示在桌面上的位置
this.setSize(300, 200); // 设置窗体大小
this.setResizable(false); // 窗体大小固定
}
// 程序入口
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
Cheshi frame = new Cheshi("我的计算器");
frame.setVisible(true); // 在桌面上显示窗体
}
}
/**
* 计算器核心逻辑。这个逻辑只能处理 1~2 个数的运算。
*/
class CalculatorCore {
private String displayText = "0"; // 要显示的文本
boolean reset = true;
private BigDecimal number1, number2;
private String operator;
private HashMapString, Operator operators = new HashMapString, Operator();
private HashMapString, Processor processors = new HashMapString, Processor();
CalculatorCore() {
setupOperators();
setupProcessors();
}
// 为每种命令添加处理方式
private void setupProcessors() {
processors.put("[0-9]", new Processor() {
public void calculate(String command) {
numberClicked(command);
}
});
processors.put("\\.", new Processor() {
public void calculate(String command) {
dotClicked();
}
});
processors.put("=", new Processor() {
public void calculate(String command) {
equalsClicked();
}
});
processors.put("[+\\-*/]", new Processor() {
public void calculate(String command) {
operatorClicked(command);
}
});
processors.put("C", new Processor() {
public void calculate(String command) {
clearClicked();
}
});
processors.put("CE", new Processor() {
public void calculate(String command) {
clearErrorClicked();
}
});
}
// 为每种 operator 添加处理方式
private void setupOperators() {
operators.put("+", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.add(number2);
}
});
operators.put("-", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.subtract(number2);
}
});
operators.put("*", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.multiply(number2);
}
});
operators.put("/", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.divide(number2, 30, RoundingMode.HALF_UP);
}
});
}
// 根据命令处理。这里的命令实际上就是按钮文本。
public String process(String command) {
for (String pattern : processors.keySet()) {
if (command.matches(pattern)) {
processors.get(pattern).calculate(command);
break;
}
}
return displayText;
}
// 当按下 CE 时
private void clearErrorClicked() {
if (operator == null) {
number1 = null;
} else {
number2 = null;
}
displayText = "0";
reset = true;
}
// 当按下 C 时，将计算器置为初始状态。
private void clearClicked() {
number1 = null;
number2 = null;
operator = null;
displayText = "0";
reset = true;
}
// 当按下 = 时
private void equalsClicked() {
calculateResult();
number1 = null;
number2 = null;
operator = null;
reset = true;
}
// 计算结果
private void calculateResult() {
number2 = new BigDecimal(displayText);
Operator oper = operators.get(operator);
if (oper != null) {
BigDecimal result = oper.process(number1, number2);
displayText = result.toString();
}
}
// 当按下 +-*/ 时（这里也可以扩展成其他中间操作符）
private void operatorClicked(String command) {
if (operator != null) {
calculateResult();
}
number1 = new BigDecimal(displayText);
operator = command;
reset = true;
}
// 当按下 . 时
private void dotClicked() {
if (displayText.indexOf(".") == -1) {
displayText += ".";
} else if (reset) {
displayText = "0.";
}
reset = false;
}
// 当按下 0-9 时
private void numberClicked(String command) {
if (reset) {
displayText = command;
} else {
displayText += command;
}
reset = false;
}
// 运算符处理接口
interface Operator {
BigDecimal process(BigDecimal number1, BigDecimal number2);
}
// 按钮处理接口
interface Processor {
void calculate(String command);
}
}
Q3: JAVA简单咋做，计算器代码
简单写了下JAVA计算器实验代码，代码如下请参照JAVA计算器实验代码：
/**
* 计算器类
*
* @author Administrator
*
*/
public class Calculator extends JFrame implements ActionListener {
private static final long serialVersionUID = 3868243398506940702L;
// 文本框
private JTextField result;
// 按钮数组
private JButton[] buttons;
// 按钮文本
private final String[] characters = { "7", "8", "9", "/", "4", "5", "6",
"*", "1", "2", "3", "-", "0", ".", "=", "+" };
// 是否为第一个输入的数字
private boolean isFirstDigit = true;
// 运算结果
private double resultNum = 0.0;
// 运算符
private String operator = "=";
public Calculator(String title) {
// 设置标题栏
super(title);
// 初始化各组件
init();
// 注册各组件监听器
registerListener();
// 显示窗体
setVisible(true);
}
/**
* 初始化各组件
*/
private void init() {
// 常用属性初始化
setSize(220, 200);
setResizable(false);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
/* 文本框对象初始化 */
result = new JTextField("0");
// 文本右对齐
result.setHorizontalAlignment(JTextField.RIGHT);
// 设置是否可编辑
result.setEditable(false);
/* 按钮初始化 */
buttons = new JButton[characters.length];
for (int i = 0; i buttons.length; i++) {
buttons[i] = new JButton(characters[i]);
buttons[i].setFocusable(false); // 不允许按钮定位焦点
}
/* 将文本框与按钮添加到窗体中 */
add(result, BorderLayout.NORTH);
JPanel pnl = new JPanel(new GridLayout(4, 4, 5, 5));
for (JButton jButton : buttons) {
pnl.add(jButton);
}
add(pnl);
this.getContentPane().setFocusable(true);
}
/**
* 注册监听器
*/
private void registerListener() {
for (JButton jButton : buttons) {
jButton.addActionListener(this);
}
// 注册键盘事件
this.getContentPane().addKeyListener(new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
String text = String.valueOf(e.getKeyChar());
if (Character.isDigit(text.charAt(0)) || ".".equals(text)) { // 数字或小数点
handleNumber(text);
} else if ("+-*/=".indexOf(text) != -1) { // 运算符
handleOperator(text);
} else if (e.getKeyCode() == 8) { // 退格键
String tmp = result.getText().trim();
if (tmp.length() == 1) {
result.setText("0");
isFirstDigit = true;
} else {
result.setText(tmp.substring(0, tmp.length() - 1));
}
}
}
});
}
@Override
public void actionPerformed(ActionEvent e) {
JButton btn = (JButton) e.getSource();
String text = btn.getText().trim();
if (Character.isDigit(text.charAt(0)) || ".".equals(text)) { // 处理数字和小数点
handleNumber(text);
} else { // 处理运算符
handleOperator(text);
}
}
/**
* 处理数字和小数点
*
* @param text
*/
private void handleNumber(String text) {
if (isFirstDigit) { // 第一次输入
if (".".equals(text)) {
this.result.setText("0.");
} else {
this.result.setText(text);
}
} else if ("0".equals(text) "0".equals(this.result.getText())) {
isFirstDigit = true;
return;
} else if (".".equals(text) this.result.getText().indexOf(".") == -1) {
this.result.setText(this.result.getText() + ".");
} else if (!".".equals(text)) {
this.result.setText(this.result.getText() + text);
}
isFirstDigit = false;
}
/**
* 处理运算符
*
* @param text
*/
private void handleOperator(String text) {
switch (operator) { // 处理各项运算 适用于JDK1.7版本的
case "+":
resultNum += Double.parseDouble(this.result.getText());
break;
case "-":
resultNum -= Double.parseDouble(this.result.getText());
break;
case "*":
resultNum *= Double.parseDouble(this.result.getText());
break;
case "/":
resultNum /= Double.parseDouble(this.result.getText());
break;
case "=":
resultNum = Double.parseDouble(this.result.getText());
break;
}
// 将文本框的值修改为运算结果
this.result.setText(String.valueOf(resultNum));
// 将点击的运算符放入operator保存
operator = text;
// 下一个数字第一次点击
isFirstDigit = true;
}
public static void main(String[] args) {
new Calculator("My Calculator");
}
}
运行结果如下：
Q4: java计算器代码
这段代码对JAVA计算器实验代码你有帮助
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.HashMap;
/**
* JAVA计算器实验代码我的计算器。MyCalculator 继承于 JFrameJAVA计算器实验代码，是计算器的界面
*/
public class MyCalculator extends JFrame {
private Border border = BorderFactory.createEmptyBorder(5, 5, 5, 5);
private JTextField textbox = new JTextField("0");
private CalculatorCore core = new CalculatorCore();
private ActionListener listener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton b = (JButton) e.getSource();
String label = b.getText();
String result = core.process(label);
textbox.setText(result);
}
};
public MyCalculator(String title) throws HeadlessException {
super(title); // 调用父类构造方法
setupFrame(); // 调整窗体属性
setupControls(); // 创建控件
}
private void setupControls() {
setupDisplayPanel(); // 创建文本面板
setupButtonsPanel(); // 创建按钮面板
}
// 创建按钮面板并添加按钮
private void setupButtonsPanel() {
JPanel panel = new JPanel();
panel.setBorder(border);
panel.setLayout(new GridLayout(4, 5, 3, 3));
createButtons(panel, new String[]{
"7", "8", "9", "+", "C",
"4", "5", "6", "-", "CE",
"1", "2", "3", "*", "", // 空字符串表示这个位置没有按钮
"0", ".", "=", "/", ""
});
this.add(panel, BorderLayout.CENTER);
}
/**
* 在指定的面板上创建按钮
*
* @param panel 要创建按钮的面板
* @param labels 按钮文字
*/
private void createButtons(JPanel panel, String[] labels) {
for (String label : labels) {
// 如果 label 为空，则表示创建一个空面板。否则创建一个按钮。
if (label.equals("")) {
panel.add(new JPanel());
} else {
JButton b = new JButton(label);
b.addActionListener(listener); // 为按钮添加侦听器
panel.add(b);
}
}
}
// 设置显示面板，用一个文本框来作为计算器的显示部分。
private void setupDisplayPanel() {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.setBorder(border);
setupTextbox();
panel.add(textbox, BorderLayout.CENTER);
this.add(panel, BorderLayout.NORTH);
}
// 调整文本框
private void setupTextbox() {
textbox.setHorizontalAlignment(JTextField.RIGHT); // 文本右对齐
textbox.setEditable(false); // 文本框只读
textbox.setBackground(Color.white); // 文本框背景色为白色
}
// 调整窗体
private void setupFrame() {
this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 当窗体关闭时程序结束
this.setLocation(100, 50); // 设置窗体显示在桌面上的位置
this.setSize(300, 200); // 设置窗体大小
this.setResizable(false); // 窗体大小固定
}
// 程序入口
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
MyCalculator frame = new MyCalculator("我的计算器");
frame.setVisible(true); // 在桌面上显示窗体
}
}
/**
* 计算器核心逻辑。这个逻辑只能处理 1~2 个数的运算。
*/
class CalculatorCore {
private String displayText = "0"; // 要显示的文本
boolean reset = true;
private BigDecimal number1, number2;
private String operator;
private HashMapString, Operator operators = new HashMapString, Operator();
private HashMapString, Processor processors = new HashMapString, Processor();
CalculatorCore() {
setupOperators();
setupProcessors();
}
// 为每种命令添加处理方式
private void setupProcessors() {
processors.put("[0-9]", new Processor() {
public void calculate(String command) {
numberClicked(command);
}
});
processors.put("\\.", new Processor() {
public void calculate(String command) {
dotClicked();
}
});
processors.put("=", new Processor() {
public void calculate(String command) {
equalsClicked();
}
});
processors.put("[+\\-*/]", new Processor() {
public void calculate(String command) {
operatorClicked(command);
}
});
processors.put("C", new Processor() {
public void calculate(String command) {
clearClicked();
}
});
processors.put("CE", new Processor() {
public void calculate(String command) {
clearErrorClicked();
}
});
}
// 为每种 operator 添加处理方式
private void setupOperators() {
operators.put("+", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.add(number2);
}
});
operators.put("-", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.subtract(number2);
}
});
operators.put("*", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.multiply(number2);
}
});
operators.put("/", new Operator() {
public BigDecimal process(BigDecimal number1, BigDecimal number2) {
return number1.divide(number2, 30, RoundingMode.HALF_UP);
}
});
}
// 根据命令处理。这里的命令实际上就是按钮文本。
public String process(String command) {
for (String pattern : processors.keySet()) {
if (command.matches(pattern)) {
processors.get(pattern).calculate(command);
break;
}
}
return displayText;
}
// 当按下 CE 时
private void clearErrorClicked() {
if (operator == null) {
number1 = null;
} else {
number2 = null;
}
displayText = "0";
reset = true;
}
// 当按下 C 时，将计算器置为初始状态。
private void clearClicked() {
number1 = null;
number2 = null;
operator = null;
displayText = "0";
reset = true;
}
// 当按下 = 时
private void equalsClicked() {
calculateResult();
number1 = null;
number2 = null;
operator = null;
reset = true;
}
// 计算结果
private void calculateResult() {
number2 = new BigDecimal(displayText);
Operator oper = operators.get(operator);
if (oper != null) {
BigDecimal result = oper.process(number1, number2);
displayText = result.toString();
}
}
// 当按下 +-*/ 时（这里也可以扩展成其他中间操作符）
private void operatorClicked(String command) {
if (operator != null) {
calculateResult();
}
number1 = new BigDecimal(displayText);
operator = command;
reset = true;
}
// 当按下 . 时
private void dotClicked() {
if (displayText.indexOf(".") == -1) {
displayText += ".";
} else if (reset) {
displayText = "0.";
}
reset = false;
}
// 当按下 0-9 时
private void numberClicked(String command) {
if (reset) {
displayText = command;
} else {
displayText += command;
}
reset = false;
}
// 运算符处理接口
interface Operator {
BigDecimal process(BigDecimal number1, BigDecimal number2);
}
// 按钮处理接口
interface Processor {
void calculate(String command);
}
}
Q5: JAVA计算器代码
import java.awt.*;
import java.applet.*;
public class CalculatorDemo extends Applet
{
TextField answerText;
Button pointButton,equalButton,plusButton;
Button minusButton,clearButton,multiButton,divisionButton;
Button[] b=new Button[10];
String currentOp,preOp;
String foreText,backText;
boolean isFloat=false;
public void init()
{
Panel p1=new Panel();
Panel p2=new Panel();
Panel p3=new Panel();
currentOp=new String("");
preOp=new String("");
foreText=new String("");
backText=new String("");
answerText=new TextField(8);
setBackground(Color.lightGray);
setForeground(Color.blue);
for(int i=9;i=0;i--)
{
b[i]=new Button(Integer.toString(i));
p2.add(b[i]);
}
pointButton=new Button(".");
equalButton=new Button("=");
equalButton.setForeground(Color.red);
clearButton=new Button("清除");
clearButton.setForeground(Color.red);
divisionButton=new Button("/");
divisionButton.setForeground(Color.red);
multiButton=new Button("*");
multiButton.setForeground(Color.red);
minusButton=new Button("-");
minusButton.setForeground(Color.red);
plusButton=new Button("+");
plusButton.setForeground(Color.red);
setLayout(new FlowLayout());
p1.setLayout(new FlowLayout());
p2.setLayout(new GridLayout(4,3));
p3.setLayout(new GridLayout(4,1));
p1.add(answerText);
p1.add(clearButton);
p2.add(pointButton);
p2.add(equalButton);
p3.add(plusButton);
p3.add(minusButton);
p3.add(multiButton);
p3.add(divisionButton);
add(p1);
add(p2);
add(p3);
}
public boolean action(Event e,Object o)
{
String s=new String("");
for(int i=0;i10;i++)
{
if(e.target==b[i]||e.target==pointButton)
{
if(e.target !=pointButton)
{
s=(String)o;
doForeText(s);
}
if((e.target==pointButton)(!isFloat))
{
isFloat=true;
s=(String)o;
if(foreText.equals(""))
{
foreText +="0.";
}
else
{
doForeText(s);
}
}
}
}
if(e.target==clearButton)
{
doClear();
}
if((e.target==clearButton)||(e.target==divisionButton)
||(e.target==plusButton)||(e.target==minusButton))
{
if(foreText !="")
{
currentOp=((String)o);
doOperator();
}
else
{
preOp=((String)o);
}
}
if(e.target==equalButton)
{
doOperator();
}
return true;
}
public void doOperator()
{
double dFore,dBack;
Double d;
if(preOp.equals(""))
{
backText=foreText;
foreText="";
answerText.setText(backText);
}
else
{
dFore=(new Double(foreText)).doubleValue();
dBack=(new Double(backText)).doubleValue();
foreText="";
backText=answerText.getText();
if(preOp.equals("+"))
{
d=new Double((dBack+dFore));
answerText.setText(d.toString());
backText=d.toString();
}
if(preOp.equals("-"))
{
d=new Double((dBack-dFore));
answerText.setText(d.toString());
backText=d.toString();
}
if(preOp.equals("*"))
{
d=new Double((dBack*dFore));
answerText.setText(d.toString());
backText=d.toString();
}
if(preOp.equals("/"))
{
if(dFore==0)
{
answerText.setText("除数不能为0");
return;
}
d=new Double((dBack/dFore));
answerText.setText(d.toString());
backText=d.toString();
}
}
preOp=currentOp;
}
public void doForeText(String s)
{
foreText +=s;
answerText.setText(foreText);
}
public void doBackText(String s)
{
backText=foreText;
foreText="";
answerText.setText(foreText);
}
public void doClear()
{
currentOp="";
preOp="";
foreText="";
backText="";
isFloat=false;
answerText.setText("");
}
}
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