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求计算器Java代码。。。
import java.awt.*;
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import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
class JPanelEa1 extends JFrame implements MenuListener,ActionListener
{
JPanel mainp,p1,p2,p3,p4;
JTextField jt1;
JMenuItem mnuCopy;
JMenuItem mnuPaste;
JButton bM;
boolean isDouble = false;// 是否为实数
int opFlag = -1;
static double t1 = 0, t2 = 0, t3 = 0, result = 0;
static int opflag1 = -1, opflag2 = -1, flag = 0, resflag = 1;
int preOp, currentOp = 0;// 标准位
double op1 = 0, op2 = 0;// 操作数
double n3;
StringBuffer buf = new StringBuffer(20);
StringBuffer copyBoard = new StringBuffer(20);// 剪贴板
StringBuffer memory = new StringBuffer(20);// M系列
StringBuffer str = new StringBuffer();
public JPanelEa1()
{
p1=new JPanel();
p1.setLayout(new GridLayout(2,1,10,10));
JMenuBar mnuNotepad=new JMenuBar();
JMenu mnuEdit=new JMenu("编辑(E)");
mnuEdit.setMnemonic(KeyEvent.VK_E);
JMenu mnuCheck=new JMenu("查看(V)");
mnuCheck.setMnemonic(KeyEvent.VK_V);
JMenu mnuHelp=new JMenu("帮助(H)");
mnuCopy=new JMenuItem("复制(C)");
mnuPaste=new JMenuItem("粘贴(P)");
JMenuItem mnuVisit=new JMenuItem("查看帮助(V)");
JMenuItem mnuAbout=new JMenuItem("关于计算器(A)");
JSeparator sep=new JSeparator();
jt1=new JTextField("0.");
jt1.setEnabled(false);
jt1.setHorizontalAlignment(JTextField.RIGHT);
mnuEdit.addMenuListener(this);
mnuCheck.addMenuListener(this);
mnuHelp.addMenuListener(this);
mnuCopy.addActionListener(this);
mnuPaste.addActionListener(this);
mnuVisit.addActionListener(this);
mnuAbout.addActionListener(this);
mnuNotepad.add(mnuEdit);
mnuNotepad.add(mnuCheck);
mnuNotepad.add(mnuHelp);
mnuEdit.add(mnuCopy);
mnuEdit.add(mnuPaste);
mnuEdit.add(sep);
mnuHelp.add(mnuVisit);
mnuHelp.add(sep);
mnuHelp.add(mnuAbout);
p1.add(mnuNotepad);
p1.add(jt1);
p2=new JPanel();
p2.setLayout(new FlowLayout(FlowLayout.CENTER));
bM = new JButton(" ");
bM.setEnabled(false);
p2.add(bM);
Button b25=new Button("Backspace");
b25.addActionListener(this);
Button b26=new Button("CE");
b26.addActionListener(this);
Button b27=new Button("C");
b27.addActionListener(this);
p2.add(b25);
p2.add(b26);
p2.add(b27);
p3=new JPanel();
p3.setLayout(new GridLayout(4,6));
Button button1=new Button("MC");
button1.addActionListener(this);
Button button2=new Button("7");
button2.addActionListener(this);
Button button3=new Button("8");
button3.addActionListener(this);
Button button4=new Button("9");
button4.addActionListener(this);
Button button5=new Button("/");
button5.addActionListener(this);
Button button6=new Button("sqrt");
button6.addActionListener(this);
Button button7=new Button("MR");
button7.addActionListener(this);
Button button8=new Button("4");
button8.addActionListener(this);
Button button9=new Button("5");
button9.addActionListener(this);
Button button10=new Button("6");
button10.addActionListener(this);
Button button11=new Button("*");
button11.addActionListener(this);
Button button12=new Button("%");
button12.addActionListener(this);
Button button13=new Button("MS");
button13.addActionListener(this);
Button button14=new Button("1");
button14.addActionListener(this);
Button button15=new Button("2");
button15.addActionListener(this);
Button button16=new Button("3");
button16.addActionListener(this);
Button button17=new Button("-");
button17.addActionListener(this);
Button button18=new Button("1/x");
button18.addActionListener(this);
Button button19=new Button("M+");
button19.addActionListener(this);
Button button20=new Button("0");
button20.addActionListener(this);
Button button21=new Button("+/-");
button21.addActionListener(this);
Button button22=new Button(".");
button22.addActionListener(this);
Button button23=new Button("+");
button23.addActionListener(this);
Button button24=new Button("=");
button24.addActionListener(this);
p3.add(button1);p3.add(button2);
p3.add(button3);p3.add(button4);
p3.add(button5);p3.add(button6);
p3.add(button7);p3.add(button8);
p3.add(button9);p3.add(button10);
p3.add(button11);p3.add(button12);
p3.add(button13);p3.add(button14);
p3.add(button15);p3.add(button16);
p3.add(button17);p3.add(button18);
p3.add(button19);p3.add(button20);
p3.add(button21);p3.add(button22);
p3.add(button23);p3.add(button24);
setSize(250,150);
mainp=new JPanel();
mainp.setLayout(new GridLayout(3,1));
mainp.add(p1);
mainp.add(p2);
mainp.add(p3);
setContentPane(mainp);
setTitle("计算器");
setSize(300,300);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent e)
{
String s= e.getActionCommand();
if (s.equals("复制(C)")) {
String temp = jt1.getText().trim();
copyBoard.replace(0, copyBoard.length(), temp);
mnuPaste.setEnabled(true);
} else if (s.equals("粘贴(p)")) {
jt1.setText(copyBoard.toString());
} else if (s.equals("CE")) {
// 如果是CE则清除文本框
jt1.setText("0.");
} else if (s.equals("Backspace")) {
if (!jt1.getText().trim().equals("0.")) {
// 如果文本框中有内容
if (str.length() != 1 str.length() != 0) {
jt1.setText(str.delete(str.length() - 1, str.length())
.toString());
} else {
jt1.setText("0.");
str.setLength(0);
}
}
op2 = Double.parseDouble(jt1.getText().trim());
} else if (s.equals("C")) {
// 如果是C删除当前计算
jt1.setText("0.");
op1 = op2 = 0;
str.replace(0, str.length(), " ");
preOp = currentOp = 0;
} else if (s.equals("MC")) {
// 如果是MC则清除缓冲区
String temp = "";
memory.replace(0, memory.length(), temp);
bM.setText(" ");
} else if (s.equals("MR")) {
// 如果按键为MR则恢复缓冲区的数到文本框
jt1.setText(memory.toString());
} else if (s.equals("MS")) {
// 如果按键为MS则将文本框的数存入缓冲区
String s1 = jt1.getText().trim();
memory.replace(0, memory.length(), s1);
bM.setText("M");
} else if (s.equals("M+")) {
// 如果按键为MS则将文本框值与缓冲区的数相加但不显示结果
String temp1 = jt1.getText().trim();
double dtemp = Double.parseDouble(temp1);
String temp2 = memory.toString();
dtemp += Double.parseDouble(temp2);
temp1 = String.valueOf(dtemp);
memory.replace(0, memory.length(), temp1);
} else if (s.equals("1/x")) {
// 如果按键为1/x则将文本框中的数据为它的倒数
String temp = jt1.getText().trim();
double dtemp = Double.parseDouble(temp);
jt1.setText("" + 1 / dtemp);
} else if (s.equals("sqrt")) {
// 如果按键为sqrt则将文本框中的内容求平方根
String temp = jt1.getText().trim();
double dtemp = Double.parseDouble(temp);
jt1.setText("" + Math.sqrt(dtemp));
} else if (s.equals("+")) {
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 1;
op2 = 0;
jt1.setText("" + op1);
} else {
currentOp = preOp;
preOp = 1;
switch (currentOp) {
case 1:
op1 += op2;
jt1.setText("" + op1);
break;
case 2:
op1 -= op2;
jt1.setText("" + op1);
break;
case 3:
op1 *= op2;
jt1.setText("" + op1);
break;
case 4:
op1 /= op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("-")) {
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 2;// op1=op2;op2=0;
jt1.setText("" + op1);
} else {
currentOp = preOp;
preOp = 2;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("*"))// *
{
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 3;// op1=op2;op2=1;
jt1.setText("" + op1);// op1=op2;
} else {
currentOp = preOp;
preOp = 3;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("/"))// /
{
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 4;// op2=1;
jt1.setText("" + op1);// op1=op2;
} else {
currentOp = preOp;
preOp = 4;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("="))// =
{
if (currentOp == 0) {
str.setLength(0);
jt1.setText("" + op2);
} else {
str.setLength(0);
currentOp = preOp;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
currentOp = 0;
op2 = 0;
}
} else if (s.equals(".")) {
isDouble = true;
if (jt1.getText().trim().indexOf('.') != -1)
;
else {
if (jt1.getText().trim().equals("0")) {
str.setLength(0);
jt1.setText((str.append("0" + s)).toString());
}
// else
// if(jt1.getText().trim().equals("")){}//如果初时显示为空则不做任何操作
else {
jt1.setText((str.append(s)).toString());
}
}
} else if (s.equals("0"))// 如果选择的是"0"这个数字键
{
if (jt1.getText().trim().equals("0.")) {
} else {
jt1.setText(str.append(s).toString());
op2 = Double.parseDouble(jt1.getText().trim());
}
} else {
jt1.setText(str.append(s).toString());
op2 = Double.parseDouble(jt1.getText().trim());
if (currentOp == 0)
op1 = op2;
}
}
public static void main(String args[])
{
JPanelEa1 g=new JPanelEa1();
}
@Override
public void menuSelected(MenuEvent e) {
// TODO Auto-generated method stub
}
@Override
public void menuDeselected(MenuEvent e) {
// TODO Auto-generated method stub
}
@Override
public void menuCanceled(MenuEvent e) {
// TODO Auto-generated method stub
}
}
求java计算器的代码
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class Calculator extends JFrame{
private float op1,op2;//定义两个变量存放需要运算的值
private String str="";//定义str去和text进行交叉赋值
private String opr,co;//opr存放符合，co用来存放复制的内容
private double re;//用来存放运算的结果
private boolean bo=false;//是否进行了+-*/运算
private boolean btime=false;//时间开关
Container contentpane=this.getContentPane();
JPanel panel1=new JPanel(new BorderLayout()),
panel2=new JPanel(new FlowLayout()),
panel3=new JPanel(new GridLayout(4,5)),
panel4=new JPanel(new BorderLayout()),
panel5=new JPanel(new BorderLayout());
//菜单栏
JMenuBar menubar=new JMenuBar();
JMenu edit=new JMenu("编辑(E)"),
find=new JMenu("查看(V)"),
help=new JMenu("帮助(H)");
JMenuItem copy=new JMenuItem("复制(C)",'C'),
paste=new JMenuItem("粘贴(P)",'P'),
standard=new JMenuItem("标准型(T)",'T'),
science=new JMenuItem("科学型(S)",'S'),
numarray=new JMenuItem("数字分组(I)",'I'),
helptopic=new JMenuItem("帮助主题(H)",'H'),
aboutcal=new JMenuItem("关于计算器(A)",'A');
//输入文本框
JTextField text=new JTextField(25);
//数字键
JButton one=new JButton("1"),
two=new JButton("2"),
three=new JButton("3"),
four=new JButton("4"),
five=new JButton("5"),
six=new JButton("6"),
seven=new JButton("7"),
eight=new JButton("8"),
nine=new JButton("9"),
zero=new JButton("0");
//功能键
JButton division=new JButton("/"),
multiply=new JButton("*"),
addition=new JButton("+"),
subtration=new JButton("-"),
sqrt=new JButton("sqrt"),
residual=new JButton("%"),
sign=new JButton("+/-"),
dot=new JButton("."),
reciprocal=new JButton("1/X"),
amount=new JButton("="),
backspace=new JButton("Backspace"),
ce=new JButton("CE"),
c=new JButton("C"),
time=new JButton("time");
public Calculator() {
contentpane.setLayout(new BorderLayout());
//textField文本从右边开始写
text.setHorizontalAlignment(SwingConstants.RIGHT);
text.setText("0.");
//菜单栏添加
edit.add(copy);
edit.add(paste);
find.add(standard);
find.add(science);
find.addSeparator();
find.add(numarray);
help.add(helptopic);
help.addSeparator();
help.add(aboutcal);
//把组件添加至容器中
menubar.add(edit);
menubar.add(find);
menubar.add(help);
panel1.add(menubar,"North");
panel1.add(text,"West");
//添加数字、功能键至panel2、panel3
panel2.add(backspace);
panel2.add(ce);
panel2.add(c);
panel2.add(time);
panel3.add(seven);
panel3.add(eight);
panel3.add(nine);
panel3.add(division);
panel3.add(sqrt);
panel3.add(four);
panel3.add(five);
panel3.add(six);
panel3.add(multiply);
panel3.add(residual);
panel3.add(one);
panel3.add(two);
panel3.add(three);
panel3.add(subtration);
panel3.add(reciprocal);
panel3.add(zero);
panel3.add(sign);
panel3.add(dot);
panel3.add(addition);
panel3.add(amount);
panel4.add(panel2,"North");
panel4.add(panel3,"West");
panel5.add(panel1,"North");
panel5.add(panel4,"West");
contentpane.add(panel5,"North");
//事件
//助记符
edit.setMnemonic('E');
find.setMnemonic('V');
help.setMnemonic('H');
//快捷键
KeyStroke kcopy=KeyStroke.getKeyStroke(KeyEvent.VK_C,Event.CTRL_MASK);
copy.setAccelerator(kcopy);
KeyStroke kpaste=KeyStroke.getKeyStroke(KeyEvent.VK_V,Event.CTRL_MASK);
paste.setAccelerator(kpaste);
//0-9、.的显示事件
actionlistener1 al1=new actionlistener1();
one.addActionListener(al1);
two.addActionListener(al1);
three.addActionListener(al1);
four.addActionListener(al1);
five.addActionListener(al1);
six.addActionListener(al1);
seven.addActionListener(al1);
eight.addActionListener(al1);
nine.addActionListener(al1);
//小数点的ActionListener事件
dot.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
//1.第一位就为.时改变text中内容为："0."
if(count==0){
str="0.";
text.setText(str);
}
//2.不可以重复按"."
else {if(!str.contains(".")){
str+=".";
text.setText(str);
}
else
System.out.println("您再点的话，输入的将不再是小数了！");
}
}
});
//如果第一位是0那么第二位就不可以为0
zero.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
if(bo){
if(!(str.contains("0")count==1)){
str="";
str+="0";
text.setText(str);
}else
System.out.println("您再点的话，输入的将不再是数字了！");
}
else{
if(!(str.contains("0")count==1)){
str+="0";
text.setText(str);
}else
System.out.println("您再点的话，输入的将不再是数字了！");
}
bo=false;
}
});
//+、-、*、/、%运算
actionlistener3 al3=new actionlistener3();
addition.addActionListener(al3);
subtration.addActionListener(al3);
multiply.addActionListener(al3);
division.addActionListener(al3);
residual.addActionListener(al3);
//CE和C清空按钮时间
actionlistener2 al2=new actionlistener2();
ce.addActionListener(al2);
c.addActionListener(al2);
//退格键
backspace.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length()-1;
if(bo==false){
if(count=0){
str=str.substring(0,count);
text.setText(str);
}
else
text.setText("0.");
}else
System.out.println("您现在正进行法则运算！");
}
});
//求平方根
sqrt.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
if(count!=0){
op1=Float.parseFloat(text.getText());
re=Math.sqrt(op1);
String str1=String.valueOf(re);
text.setText(str1);
str="";
}
else
System.out.println("您现在的按sqrt键毫无意义");
}
});
//求倒数
reciprocal.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
if(count!=0){
op1=Float.parseFloat(text.getText());
if(op1!=0){
re=1/op1;
String str1=String.valueOf(re);
text.setText(str1);
str=str1;
}
else{
text.setText("除数不可以为0的");
str="";
}
}
else
System.out.println("您现在的按1/X键毫无意义");
}
});
//=事件
amount.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
op2=Float.parseFloat(str);
//需判断进行那种运算法则
if(opr=="+"){//加法运算
re=op1+op2;
String str1=String.valueOf(re);
text.setText(str1);
str=String.valueOf(re);
}else{
if(opr=="-"){//减法运算
re=op1-op2;
String str1=String.valueOf(re);
text.setText(str1);
str=String.valueOf(re);
}else{
if(opr=="*"){//乘法运算
re=op1*op2;
String str1=String.valueOf(re);
text.setText(str1);
str=String.valueOf(re);
}else{
if(opr=="/"op2!=0){//除法运算
re=op1/op2;
String str1=String.valueOf(re);
text.setText(str1);
str=String.valueOf(re);
}else{
if(opr=="%"){//取余运算
re=op1%op2;
String str1=String.valueOf(re);
text.setText(str1);
str="";
}
else if(op2==0){
text.setText("除数不可以为0的");
str="";
}
}
}
}
}
//打印看看
System.out.print(op1);
System.out.print(opr);
System.out.print(op2+"=");
System.out.print(re);
System.out.println();
}
});
//复制事件
copy.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
if(count!=0){
co=text.getText();
}
else
System.out.println("没有可复制的对象");
}
});
//粘贴事件
paste.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
str=co;
text.setText(str);
}
});
//时间事件
time.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
if(btime==false){
String st=(new Date()).toString();
text.setText(st);
str="";
btime=true;
}
else{
text.setText(str);
btime=false;
}
}
});
//+/-事件
sign.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int a=Integer.valueOf(str);
a=a*(-1);
str=String.valueOf(a);
text.setText(str);
}
});
}
//定义1-9按钮在text中显示的内部类
class actionlistener1 implements ActionListener{
public void actionPerformed(ActionEvent e){
JButton button=(JButton)e.getSource();
String btext=button.getText();
//如果第一位为0再输入其他非零的整数时将零忽略
if(bo){
if(str.indexOf("0")==0str.length()==1){
str="";
str+=btext;
text.setText(str);
}else{
str="";
str+=btext;
text.setText(str);}
}else{
if(str.indexOf("0")==0str.length()==1){
str="";
str+=btext;
text.setText(str);
}else{
str+=btext;
text.setText(str);
}
}
bo=false;
}
}
//定义清空text中内容的内部类
class actionlistener2 implements ActionListener{
public void actionPerformed(ActionEvent e){
str="";
text.setText("0.");
}
}
//定义+、-、*、/、%运算的内部类
class actionlistener3 implements ActionListener{
public void actionPerformed(ActionEvent e){
int count;
count=str.length();
if(count!=0){
JButton button=(JButton)e.getSource();
opr=button.getText();
op1=Float.parseFloat(str);
bo=true;
}
else
System.out.println("您现在的按键毫无意义！");
}
}
public static void main(String[] args){
Calculator cc=new Calculator();
cc.pack();
cc.setResizable(false);//不可最大化
cc.setVisible(true);
cc.setTitle("计算器");
cc.setDefaultCloseOperation(EXIT_ON_CLOSE);
Dimension scmsize=Toolkit.getDefaultToolkit().getScreenSize();
int w=cc.getSize().width;
int h=cc.getSize().height;
int x=(scmsize.width-w)/2;
int y=(scmsize.height-h)/2;
cc.setLocation(x, y);
}
}
java计算器，如果初始状态是0那么再输入其他数字时，把0覆盖掉。例如0，输入6，显示"6"，而不是"06"
Num = textField.getText() + Num;
这里如果 textField.getText() 获取到的是 0
Num 为输入的 1
textField.getText() + Num 这里不会进行运行 0+1=1
而是 "0"+"1"="01" 字符串拼接
java计算器的源代码
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import javax.swing.*;
public class Counter extends Frame
{
//声明三个面板的布局
GridLayout gl1,gl2,gl3;
Panel p0,p1,p2,p3;
JTextField tf1;
TextField tf2;
Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19,b20,b21,b22,b23,b24,b25,b26;
StringBuffer str;//显示屏所显示的字符串
double x,y;//x和y都是运算数
int z;//Z表示单击了那一个运算符.0表示"+",1表示"-",2表示"*",3表示"/"
static double m;//记忆的数字
public Counter()
{
gl1=new GridLayout(1,4,10,0);//实例化三个面板的布局
gl2=new GridLayout(4,1,0,15);
gl3=new GridLayout(4,5,10,15);
tf1=new JTextField(27);//显示屏
tf1.setHorizontalAlignment(JTextField.RIGHT);
tf1.setEnabled(false);
tf1.setText("0");
tf2=new TextField(10);//显示记忆的索引值
tf2.setEditable(false);
//实例化所有按钮、设置其前景色并注册监听器
b0=new Button("Backspace");
b0.setForeground(Color.red);
b0.addActionListener(new Bt());
b1=new Button("CE");
b1.setForeground(Color.red);
b1.addActionListener(new Bt());
b2=new Button("C");
b2.setForeground(Color.red);
b2.addActionListener(new Bt());
b3=new Button("MC");
b3.setForeground(Color.red);
b3.addActionListener(new Bt());
b4=new Button("MR");
b4.setForeground(Color.red);
b4.addActionListener(new Bt());
b5=new Button("MS");
b5.setForeground(Color.red);
b5.addActionListener(new Bt());
b6=new Button("M+");
b6.setForeground(Color.red);
b6.addActionListener(new Bt());
b7=new Button("7");
b7.setForeground(Color.blue);
b7.addActionListener(new Bt());
b8=new Button("8");
b8.setForeground(Color.blue);
b8.addActionListener(new Bt());
b9=new Button("9");
b9.setForeground(Color.blue);
b9.addActionListener(new Bt());
b10=new Button("/");
b10.setForeground(Color.red);
b10.addActionListener(new Bt());
b11=new Button("sqrt");
b11.setForeground(Color.blue);
b11.addActionListener(new Bt());
b12=new Button("4");
b12.setForeground(Color.blue);
b12.addActionListener(new Bt());
b13=new Button("5");
b13.setForeground(Color.blue);
b13.addActionListener(new Bt());
b14=new Button("6");
b14.setForeground(Color.blue);
b14.addActionListener(new Bt());
b15=new Button("*");
b15.setForeground(Color.red);
b15.addActionListener(new Bt());
b16=new Button("%");
b16.setForeground(Color.blue);
b16.addActionListener(new Bt());
b17=new Button("1");
b17.setForeground(Color.blue);
b17.addActionListener(new Bt());
b18=new Button("2");
b18.setForeground(Color.blue);
b18.addActionListener(new Bt());
b19=new Button("3");
b19.setForeground(Color.blue);
b19.addActionListener(new Bt());
b20=new Button("-");
b20.setForeground(Color.red);
b20.addActionListener(new Bt());
b21=new Button("1/X");
b21.setForeground(Color.blue);
b21.addActionListener(new Bt());
b22=new Button("0");
b22.setForeground(Color.blue);
b22.addActionListener(new Bt());
b23=new Button("+/-");
b23.setForeground(Color.blue);
b23.addActionListener(new Bt());
b24=new Button(".");
b24.setForeground(Color.blue);
b24.addActionListener(new Bt());
b25=new Button("+");
b25.setForeground(Color.red);
b25.addActionListener(new Bt());
b26=new Button("=");
b26.setForeground(Color.red);
b26.addActionListener(new Bt());
//实例化四个面板
p0=new Panel();
p1=new Panel();
p2=new Panel();
p3=new Panel();
//创建一个空字符串缓冲区
str=new StringBuffer();
//添加面板p0中的组件和设置其在框架中的位置和大小
p0.add(tf1);
p0.setBounds(10,25,300,40);
//添加面板p1中的组件和设置其在框架中的位置和大小
p1.setLayout(gl1);
p1.add(tf2);
p1.add(b0);
p1.add(b1);
p1.add(b2);
p1.setBounds(10,65,300,25);
//添加面板p2中的组件并设置其的框架中的位置和大小
p2.setLayout(gl2);
p2.add(b3);
p2.add(b4);
p2.add(b5);
p2.add(b6);
p2.setBounds(10,110,40,150);
//添加面板p3中的组件并设置其在框架中的位置和大小
p3.setLayout(gl3);//设置p3的布局
p3.add(b7);
p3.add(b8);
p3.add(b9);
p3.add(b10);
p3.add(b11);
p3.add(b12);
p3.add(b13);
p3.add(b14);
p3.add(b15);
p3.add(b16);
p3.add(b17);
p3.add(b18);
p3.add(b19);
p3.add(b20);
p3.add(b21);
p3.add(b22);
p3.add(b23);
p3.add(b24);
p3.add(b25);
p3.add(b26);
p3.setBounds(60,110,250,150);
//设置框架中的布局为空布局并添加4个面板
setLayout(null);
add(p0);
add(p1);
add(p2);
add(p3);
setResizable(false);//禁止调整框架的大小
//匿名类关闭窗口
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e1)
{
System.exit(0);
}
});
setBackground(Color.lightGray);
setBounds(100,100,320,280);
setVisible(true);
}
//构造监听器
class Bt implements ActionListener
{
public void actionPerformed(ActionEvent e2)
{
try{
if(e2.getSource()==b1)//选择"CE"清零
{
tf1.setText("0");//把显示屏清零
str.setLength(0);//清空字符串缓冲区以准备接收新的输入运算数
}
else if(e2.getSource()==b2)//选择"C"清零
{
tf1.setText("0");//把显示屏清零
str.setLength(0);
}
else if(e2.getSource()==b23)//单击"+/-"选择输入的运算数是正数还是负数
{
x=Double.parseDouble(tf1.getText().trim());
tf1.setText(""+(-x));
}
else if(e2.getSource()==b25)//单击加号按钮获得x的值和z的值并清空y的值
{
x=Double.parseDouble(tf1.getText().trim());
str.setLength(0);//清空缓冲区以便接收新的另一个运算数
y=0d;
z=0;
}
else if(e2.getSource()==b20)//单击减号按钮获得x的值和z的值并清空y的值
{
x=Double.parseDouble(tf1.getText().trim());
str.setLength(0);
y=0d;
z=1;
}
else if(e2.getSource()==b15)//单击乘号按钮获得x的值和z的值并清空y的值
{
x=Double.parseDouble(tf1.getText().trim());
str.setLength(0);
y=0d;
z=2;
}
else if(e2.getSource()==b10)//单击除号按钮获得x的值和z的值并空y的值
{
x=Double.parseDouble(tf1.getText().trim());
str.setLength(0);
y=0d;
z=3;
}
else if(e2.getSource()==b26)//单击等号按钮输出计算结果
{
str.setLength(0);
switch(z)
{
case 0 : tf1.setText(""+(x+y));break;
case 1 : tf1.setText(""+(x-y));break;
case 2 : tf1.setText(""+(x*y));break;
case 3 : tf1.setText(""+(x/y));break;
}
}
else if(e2.getSource()==b24)//单击"."按钮输入小数
{
if(tf1.getText().trim().indexOf(′.′)!=-1)//判断字符串中是否已经包含了小数点
{
}
else//如果没数点有小
{
if(tf1.getText().trim().equals("0"))//如果初时显示为0
{
str.setLength(0);
tf1.setText((str.append("0"+e2.getActionCommand())).toString());
}
else if(tf1.getText().trim().equals(""))//如果初时显示为空则不做任何操作
{
}
else
{
tf1.setText(str.append(e2.getActionCommand()).toString());
}
}
y=0d;
}
else if(e2.getSource()==b11)//求平方根
{
x=Double.parseDouble(tf1.getText().trim());
tf1.setText("数字格式异常");
if(x0)
tf1.setText("负数没有平方根");
else
tf1.setText(""+Math.sqrt(x));
str.setLength(0);
y=0d;
}
else if(e2.getSource()==b16)//单击了"%"按钮
{
x=Double.parseDouble(tf1.getText().trim());
tf1.setText(""+(0.01*x));
str.setLength(0);
y=0d;
}
else if(e2.getSource()==b21)//单击了"1/X"按钮
{
x=Double.parseDouble(tf1.getText().trim());
if(x==0)
{
tf1.setText("除数不能为零");
}
else
{
tf1.setText(""+(1/x));
}
str.setLength(0);
y=0d;
}
else if(e2.getSource()==b3)//MC为清除内存
{
m=0d;
tf2.setText("");
str.setLength(0);
}
else if(e2.getSource()==b4)//MR为重新调用存储的数据
{
if(tf2.getText().trim()!="")//有记忆数字
{
tf1.setText(""+m);
}
}
else if(e2.getSource()==b5)//MS为存储显示的数据
{
m=Double.parseDouble(tf1.getText().trim());
tf2.setText("M");
tf1.setText("0");
str.setLength(0);
}
else if(e2.getSource()==b6)//M+为将显示的数字与已经存储的数据相加要查看新的数字单击MR
{
m=m+Double.parseDouble(tf1.getText().trim());
}
else//选择的是其他的按钮
{
if(e2.getSource()==b22)//如果选择的是"0"这个数字键
{
if(tf1.getText().trim().equals("0"))//如果显示屏显示的为零不做操作
{
}
else
{
tf1.setText(str.append(e2.getActionCommand()).toString());
y=Double.parseDouble(tf1.getText().trim());
}
}
else if(e2.getSource()==b0)//选择的是“BackSpace”按钮
{
if(!tf1.getText().trim().equals("0"))//如果显示屏显示的不是零
{
if(str.length()!=1)
{
tf1.setText(str.delete(str.length()-1,str.length()).toString());//可能抛出字符串越界异常
}
else
{
tf1.setText("0");
str.setLength(0);
}
}
y=Double.parseDouble(tf1.getText().trim());
}
else//其他的数字键
{
tf1.setText(str.append(e2.getActionCommand()).toString());
y=Double.parseDouble(tf1.getText().trim());
}
}
}
catch(NumberFormatException e){
tf1.setText("数字格式异常");
}
catch(StringIndexOutOfBoundsException e){
tf1.setText("字符串索引越界");
}
}
}
public static void main(String args[])
{
new Counter();
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);
}
}
文章题目：java计算器数字0代码的简单介绍
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