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java简单计算器代码,java简单计算器代码能实现科学计算
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java编一个计算器的代码
界面漂亮堪比系统自带计算器，功能完美加减乘除开平方等等全部具备，还有清零按钮，小数点的使用，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！
Java图形界面简单计算器
示例代码如下，请参考：
package test.com.test;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Cal {
TextField tf = new TextField(40); //显示文本框
StringBuffer s1 = new StringBuffer(); //记录运算数字，以及保留结果
StringBuffer s2 = new StringBuffer(); //记录运算数字，保留上一个输入的数字或运算结果
static String flag = new String(); //标记运算符号：+，-，*，/
boolean start = true; //标记运算开始或结束,保证一次运算之后，第二次进行运算时能同时清空显示界面，即s1为空
public void init(){
//主界面
JFrame f = new JFrame("计算器");
JPanel p1 = new JPanel();
p1.add(tf);
f.add(p1,BorderLayout.NORTH);
JPanel p2 = new JPanel();
p2.setLayout(new GridLayout(1,3));
//动作监听器
ActionListener listen =new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
//输入数字0~9
if(arg0.getActionCommand()=="0"){
if(!s1.toString().equals(new String())){
if(!start){
//s1清零，保证可以重新输入数字
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("0").toString());
}
}
if(arg0.getActionCommand()=="1"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("1").toString());
}
if(arg0.getActionCommand()=="2"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("2").toString());
}
if(arg0.getActionCommand()=="3"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("3").toString());
}
if(arg0.getActionCommand()=="4"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("4").toString());
}
if(arg0.getActionCommand()=="5"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("5").toString());
}
if(arg0.getActionCommand()=="6"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("6").toString());
}
if(arg0.getActionCommand()=="7"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("7").toString());
}
if(arg0.getActionCommand()=="8"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("8").toString());
}
if(arg0.getActionCommand()=="9"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
tf.setText(s1.append("9").toString());
}
//输入小数点
if(arg0.getActionCommand()=="."){
if(!start){
s1.delete(0, s1.length());
}
start=true;
if(s1.toString().equals(new String()))
tf.setText(s1.append("0.").toString());
else if(s1.length()==1s1.charAt(0)=='-')
tf.setText(s1.append("0.").toString());
else
tf.setText(s1.append(".").toString());
}
//输入负号
if(arg0.getActionCommand()=="+/-"){
if(!start){
s1.delete(0, s1.length());
}
start = true;
if(s1.toString().equals(new String()))
tf.setText(s1.append('-').toString());
}
//退格Backspace
if(arg0.getActionCommand()=="Backspace"){
start = true;
if(s1.length()!=0){
//删除最后输入的一位
s1.deleteCharAt(s1.length()-1);
tf.setText(s1.toString());
}
}
//归零CE
if(arg0.getActionCommand()=="CE"){
//清空所有，start标记设为true
start = true;
s1.delete(0, s1.length());
s2.delete(0, s2.length());
tf.setText(s1.toString());
}
//清除C
if(arg0.getActionCommand()=="C"){
//清空当前输入，即s1清零
start = true;
s1.delete(0, s1.length());
tf.setText(s1.toString());
}
//加号
if(arg0.getActionCommand()=="+"){
start = true;
flag="+";
//s2接收s1的值
s2.append(String.valueOf(s1.toString()));
//s1清零，重新接收下一个数据
s1.delete(0, s1.length());
tf.setText(s1.toString());
}
//减号
if(arg0.getActionCommand()=="-"){
start = true;
flag="-";
s2.append(String.valueOf(s1.toString()));
s1.delete(0, s1.length());
tf.setText(s1.toString());
}
//乘号
if(arg0.getActionCommand()=="*"){
start = true;
flag="*";
s2.append(String.valueOf(s1.toString()));
s1.delete(0, s1.length());
tf.setText(s1.toString());
}
//除号
if(arg0.getActionCommand()=="/"){
start = true;
flag="/";
s2.append(String.valueOf(s1.toString()));
s1.delete(0, s1.length());
tf.setText(s1.toString());
}
//开根号
if(arg0.getActionCommand()=="sqrt"){
start =false;
double s=Double.parseDouble(s1.toString());
s1.delete(0, s1.length());
tf.setText(s1.append(String.valueOf(Math.sqrt(s))).toString());
}
//求%
if(arg0.getActionCommand()=="%"){
start =false;
double s=Double.parseDouble(s1.toString());
s1.delete(0, s1.length());
tf.setText(s1.append(String.valueOf(s/100)).toString());
}
//求1/x
if(arg0.getActionCommand()=="1/x"!s1.toString().equals(new String())Double.parseDouble(s1.toString())!=0){
start =false;
double s=Double.parseDouble(s1.toString());
s1.delete(0, s1.length());
tf.setText(s1.append(String.valueOf(1/s)).toString());
}
//求结果
if(arg0.getActionCommand()=="="s1.length()!=0s2.length()!=0){
//start标记为false
start =false;
//分别获取s1和s2的值
double s4=Double.parseDouble(s1.toString());
double s3=Double.parseDouble(s2.toString());
//清空s1和s2，便于开始下一次运算
s1.delete(0, s1.length());
s2.delete(0, s2.length());
//四则运算
if(flag=="+"){
tf.setText(s1.append(String.valueOf(s3+s4)).toString());
}
if(flag=="-"){
tf.setText(s1.append(String.valueOf(s3-s4)).toString());
}
if(flag=="*"){
tf.setText(s1.append(String.valueOf(s3*s4)).toString());
}
if(flag=="/"){
tf.setText(s1.append(String.valueOf(s3/s4)).toString());
}
}
}
};
//添加按钮以及监听器
JButton bks = new JButton("Backspace");
bks.addActionListener(listen);
JButton ce = new JButton("CE");
ce.addActionListener(listen);
JButton c = new JButton("C");
c.addActionListener(listen);
p2.add(bks);
p2.add(ce);
p2.add(c);
f.add(p2);
JPanel p3 = new JPanel();
p3.setLayout(new GridLayout(4,5));
JButton b1 = new JButton("7");
p3.add(b1);
b1.addActionListener(listen);
JButton b2 = new JButton("8");
p3.add(b2);
b2.addActionListener(listen);
JButton b3 = new JButton("9");
p3.add(b3);
b3.addActionListener(listen);
JButton b4 = new JButton("/");
p3.add(b4);
b4.addActionListener(listen);
JButton b5 = new JButton("sqrt");
p3.add(b5);
b5.addActionListener(listen);
JButton b6 = new JButton("4");
p3.add(b6);
b6.addActionListener(listen);
JButton b7 = new JButton("5");
p3.add(b7);
b7.addActionListener(listen);
JButton b8 = new JButton("6");
p3.add(b8);
b8.addActionListener(listen);
JButton b9 = new JButton("*");
p3.add(b9);
b9.addActionListener(listen);
JButton b10 = new JButton("%");
p3.add(b10);
b10.addActionListener(listen);
JButton b11 = new JButton("1");
p3.add(b11);
b11.addActionListener(listen);
JButton b12 = new JButton("2");
p3.add(b12);
b12.addActionListener(listen);
JButton b13 = new JButton("3");
p3.add(b13);
b13.addActionListener(listen);
JButton b14 = new JButton("-");
p3.add(b14);
b14.addActionListener(listen);
JButton b15 = new JButton("1/x");
p3.add(b15);
b15.addActionListener(listen);
JButton b16 = new JButton("0");
p3.add(b16);
b16.addActionListener(listen);
JButton b17 = new JButton("+/-");
p3.add(b17);
b17.addActionListener(listen);
JButton b18 = new JButton(".");
p3.add(b18);
b18.addActionListener(listen);
JButton b19 = new JButton("+");
p3.add(b19);
b19.addActionListener(listen);
JButton b20 = new JButton("=");
p3.add(b20);
b20.addActionListener(listen);
f.add(p3,BorderLayout.SOUTH);
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.pack();
f.setVisible(true);
}
public static void main(String args[]){
//调用方法，实现计算器
new Cal().init();
}
}
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);
}
}
怎么用JAVA编程编写一个计算器？
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。
编写类的详细步骤
1.类的基本结构：
由于这里用到了界面，所以要进行窗口界面的编程，按钮事件的处理，和计算处理界面；
package MyCaculator;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyCaculator extends JFrame {
private int add=1,sub=2,mul=3,div=4;
private int op=0;
boolean ifOp;
private String output="0";
private Button[] jba=new Button[]{new Button("7"),new Button("8"),
new Button("9"),new Button("+"),
new Button("4"),new Button("5"),new Button("6"),new Button("-"),
new Button("1"),new Button("2"),new Button("3"),new Button("*"),
new Button("0"),new Button("."),new Button("="),new Button("/")};
private JPanel jpt=new JPanel();
private JPanel jpb=new JPanel();
private JTextField jtf=new JTextField("");
private MyCaculator(){
}
private void operate(String x){
}
public String add(String x){
return output;
}
public String subtract(String x){
return output;
}
public String multiply(String x){
return output;
}
public String divide(String x){
return output;
}
public String Equals(String x){
return output;
}
public void opClean(){
}
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
public static void main(String[] args) {
}
}
2.建立构造方法：
所谓构造方法就是，对自己的主类进行初始化，代码如下：
private MyCaculator(){
jpt.setLayout(new BorderLayout());
jpt.add(jtf);
this.add(jpt,BorderLayout.NORTH);
jpb.setLayout(new GridLayout(4,4));
for(int i=0;ijba.length;i++){
jpb.add(jba[i]);
if(i==3||i==7||i==11||i==15||i==14)
jba[i].addActionListener(new setOperate_Act());
else
jba[i].addActionListener(new setLabel_Act());
}
this.add(jpb,BorderLayout.CENTER);
this.setSize(250, 200);
this.setResizable(false);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
3.建立数据计算方法
这里的数据计算方法有6个，一个是主方法其他几个是加减乘除的处理方法，代码如下：
private void operate(String x){
double x1=Double.valueOf(x);
double y=Double.valueOf(output);
switch(op){
case 0:output=x;break;
case 1:output=String.valueOf(y+x1);break;
case 2:output =String.valueOf(y-x1);break;
case 3:output =String.valueOf(y*x1);break;
case 4:
if(x1!=0) output=String.valueOf(y/x1);
else output="不能为0";
break;
}
}
public String add(String x){
operate(x);
op=add;
return output;
}
public String subtract(String x){
operate(x);
op=sub;
return output;
}
public String multiply(String x){
operate(x);
op=mul;
return output;
}
public String divide(String x){
operate(x);
op=div;
return output;
}
public String Equals(String x){
operate(x);
op=0;
return output;
}
public void opClean(){
op=0;
output ="0";
}
4.事件处理方法
这里的时间处理方法，没有建立一个整体的方法，二是在为了便于处理的方法，将按钮事件分成两个部分，并采用两个子类来实现，这两个类时内部类要写在主类内部的，代码如下：
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
if(e.getSource()==jba[3]){
jtf.setText(add(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[7]){
jtf.setText(subtract(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[11]){
jtf.setText(multiply(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[15]){
jtf.setText(divide(jtf.getText()));
ifOp=true;
}
else if(e.getSource()==jba[14]){
jtf.setText(Equals(jtf.getText()));
ifOp=true;
}
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
Button tempb=(Button)e.getSource();
if(ifOp){
jtf.setText(tempb.getLabel());
ifOp=false;
}else {
jtf.setText(jtf.getText()+tempb.getLabel());
}
}
}
5.建立main方法：
要想实现我们的代码，我们需在main方法中，实例化我们的对象。
public static void main(String[] args) {
new MyCaculator();
}
急求java简易计算器代码
试试下面的代码 绝对没有错误。
package main;
import java.awt.Button;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.math.BigDecimal;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class app7 extends JFrame implements ActionListener {
static Panel pan = new Panel();
static JTextField textField = new JTextField("0");
static Button b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, bp, ba, bs, bm, bd,
be, bc, bt, bf, bh;
private StringBuffer temp = new StringBuffer("");
private String optValue = "0";
private String optType="";
private boolean isChoiseOptType=true;
public void init() {
b0 = new Button("0");
b0.addActionListener(this);
b1 = new Button("1");
b1.addActionListener(this);
b2 = new Button("2");
b2.addActionListener(this);
b3 = new Button("3");
b3.addActionListener(this);
b4 = new Button("4");
b4.addActionListener(this);
b5 = new Button("5");
b5.addActionListener(this);
b6 = new Button("6");
b6.addActionListener(this);
b7 = new Button("7");
b7.addActionListener(this);
b8 = new Button("8");
b8.addActionListener(this);
b9 = new Button("9");
b9.addActionListener(this);
bp = new Button(".");
bp.addActionListener(this);
ba = new Button("+");
ba.addActionListener(this);
bs = new Button("-");
bs.addActionListener(this);
bm = new Button("*");
bm.addActionListener(this);
bd = new Button("/");
bd.addActionListener(this);
be = new Button("=");
be.addActionListener(this);
bc = new Button("c");
bc.addActionListener(this);
bt = new Button("退格");
bt.addActionListener(this);
bf = new Button("1/x");
bf.addActionListener(this);
bh = new Button("+/-");
bh.addActionListener(this);
this.setTitle("计算机");
this.setLayout(null);
this.setSize(260, 300);
this.setResizable(false);
GridLayout grid = new GridLayout(4, 5);
pan.setLayout(grid);
pan.setBounds(20, 60, 150, 120);
textField.setBounds(20, 35, 150, 20);
textField.setBackground(Color.cyan);
textField.setHorizontalAlignment(textField.RIGHT);
textField.setEditable(false);
pan.add(b1);
pan.add(b2);
pan.add(b3);
pan.add(ba);
pan.add(bc);
pan.add(b4);
pan.add(b5);
pan.add(b6);
pan.add(bs);
pan.add(bt);
pan.add(b7);
pan.add(b8);
pan.add(b9);
pan.add(bm);
pan.add(bf);
pan.add(b0);
pan.add(bh);
pan.add(bp);
pan.add(bd);
pan.add(be);
this.add(textField);
this.add(pan);
}
public static void main(String[] args) {
app7 frm = new app7();
frm.init();
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setVisible(true);
}
@SuppressWarnings("static-access")
@Override
public void actionPerformed(ActionEvent e) {
String value="0";
if (e.getSource().equals(b0)) {
this.temp.append(b0.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b1)) {
this.temp.append(b1.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b2)) {
this.temp.append(b2.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b3)) {
this.temp.append(b3.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b4)) {
this.temp.append(b4.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b5)) {
this.temp.append(b5.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b6)) {
this.temp.append(b6.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b7)) {
this.temp.append(b7.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b8)) {
this.temp.append(b8.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(b9)) {
this.temp.append(b9.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(bp)) {
if(this.temp.length()=0)
this.temp.append("0");
this.temp.append(bp.getLabel());
this.textField.setText(this.temp.toString());
isChoiseOptType=false;
} else if (e.getSource().equals(ba)) {
if(!isChoiseOptType){
value=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
value=value.substring(0,value.length()-1);
}
this.optValue=value;
this.temp=new StringBuffer("");
}
this.optType=ba.getLabel();
isChoiseOptType=true;
} else if (e.getSource().equals(bs)) {
if(!isChoiseOptType){
value=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
value=value.substring(0,value.length()-1);
}
this.optValue=value;
this.temp=new StringBuffer("");
}
this.optType=bs.getLabel();
isChoiseOptType=true;
} else if (e.getSource().equals(bm)) {
if(!isChoiseOptType){
value=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
value=value.substring(0,value.length()-1);
}
this.optValue=value;
this.temp=new StringBuffer("");
}
this.optType=bm.getLabel();
isChoiseOptType=true;
} else if (e.getSource().equals(bd)) {
if(!isChoiseOptType){
value=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
value=value.substring(0,value.length()-1);
}
this.optValue=value;
this.temp=new StringBuffer("");
}
this.optType=bd.getLabel();
isChoiseOptType=true;
}else if (e.getSource().equals(be)) {
if(!this.optType.equals("")){
BigDecimal opt1=new BigDecimal(this.optValue);
value=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
value=value.substring(0,value.length()-1);
}
BigDecimal opt2=new BigDecimal(value);
BigDecimal result=new BigDecimal(0);
if(this.optType.equals("+")){
result=opt1.add(opt2);
}else if(this.optType.equals("-")){
result=opt1.subtract(opt2);
}else if(this.optType.equals("*")){
result=opt1.multiply(opt2);
}else if(this.optType.equals("/")){
result=opt1.divide(opt2);
}else if(this.optType.equals("%")){
result=opt1.remainder(opt2);
}
this.textField.setText(result.toString());
this.temp=new StringBuffer("");
isChoiseOptType=false;
this.optValue="0";
}
} else if (e.getSource().equals(bc)) {
this.temp=new StringBuffer();
this.textField.setText("0");
} else if (e.getSource().equals(bt)) {
value=this.textField.getText();
value=value.substring(0,value.length()-1);
if(value.indexOf("-")=0 value.length()=1){
value="0";
this.temp=new StringBuffer("");
}else{
this.temp=new StringBuffer(value);
}
this.textField.setText(value);
}else if (e.getSource().equals(bh)) {
value=this.textField.getText();
if(value.indexOf("-")==0){
value=value.substring(1,value.length());
}else{
value="-"+value;
}
this.temp=new StringBuffer(value);
this.textField.setText(value);
} else if (e.getSource().equals(bf)) {
this.optValue=this.textField.getText();
if(value.lastIndexOf(".")==value.length()-1){
this.optValue=this.optValue.substring(0,this.optValue.length()-1);
}
Integer opt1=new Integer(this.optValue);
if(!opt1.toString().equals("0")){
this.textField.setText(1.0/opt1.intValue()+"");
System.out.println(1/opt1.intValue()+"");
}else{
this.textField.setText("0");
}
this.temp=new StringBuffer("");
this.optType="";
this.optValue="0";
}
}
}
记住类名是app7.java 包名是main. 如果有不对的地方 到时候在找我 我在线。
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
}
}
