java简易计数器

java简易计数器
package my_calculator;
public class Mainclass {
public static void main(String[] args) {
MyFrame mf=new MyFrame("Calculator");
}
}
==================================================== package my_calculator;
import java.awt.*;
import java.awt.event.*;
import java.math.*;
public class MyFrame extends Frame {
Label lab;
ButtonPanel bp;
int flag;
double result;
boolean pt;
boolean equal;
public MyFrame(String arg0) throws HeadlessException { super(arg0);
Button bt=new Button("CE");
pt=false;
equal=true;
result=0.0d;
flag=0;
lab=new Label("0",Label.RIGHT);
bp=new ButtonPanel();
setLayout(new BorderLayout());
add(lab,BorderLayout.NORTH);
add(bp,BorderLayout.CENTER);
add(bt,BorderLayout.SOUTH);
setLocation(200,200);
setSize(300,300);
setVisible(true);
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent arg0) {
System.exit(0);
}
});
bt.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
result=0.0d;
lab.setText("0");
}
});
bp.bt[0].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("7");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("7").toString());
else
lab.setText("7");
}
});
bp.bt[1].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("8");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("8").toString());
else
lab.setText("8");
}
});
bp.bt[2].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("9");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("9").toString());
else
lab.setText("9");
}
});
bp.bt[3].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
flag=1;
pt=false;
result=Double.parseDouble(lab.getText());
lab.setText("0");
}
});
bp.bt[4].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("4");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("4").toString());
else
lab.setText("4");
}
});
bp.bt[5].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("5");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("5").toString());
else
lab.setText("5");
}
});
bp.bt[6].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("6");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("6").toString());
else
lab.setText("6");
}
});
bp.bt[7].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
flag=2;
pt=false;
result=Double.parseDouble(lab.getText());
lab.setText("0");
}
});
bp.bt[8].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("1");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("1").toString());
else
lab.setText("1");
}
});
bp.bt[9].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("2");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("2").toString());
lab.setText("2");
}
});
bp.bt[10].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("3");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("3").toString());
else
lab.setText("3");
}
});
bp.bt[11].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
flag=3;
pt=false;
result=Double.parseDouble(lab.getText());
lab.setText("0");
}
});
bp.bt[12].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(equal==false){
lab.setText("0");
equal=true;
}
else if(pt||Double.parseDouble(lab.getText())!=0)
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append("0").toString());
else
lab.setText("0");
}
});
bp.bt[13].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(!pt){
pt=true;
lab.setText((new
StringBuilder(String.valueOf(lab.getText()))).append(".").toString());
}
});
bp.bt[15].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
flag=4;
pt=false;
result=Double.parseDouble(lab.getText());
lab.setText("0");
}
});
bp.bt[14].addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
if(flag==1){
result=result/Double.parseDouble(lab.getText());
lab.setText((new StringBuilder()).append(result).toString());
}
else if(flag==2){
result*=Double.parseDouble(lab.getText());
lab.setText((new StringBuilder()).append(result).toString());
}
else if(flag==3){
result-=Double.parseDouble(lab.getText());
lab.setText((new StringBuilder()).append(result).toString());
}
else if(flag==4){
result+=Double.parseDouble(lab.getText());
lab.setText((new StringBuilder()).append(result).toString());
}
equal=false;
pt=false;
}
});
}
}
============================================================= package my_calculator;
import java.awt.*;
public class ButtonPanel extends Panel {
Button bt[];
public ButtonPanel() {
super();
bt=new Button[20];
setLayout(new GridLayout(4,4));
String str="789/456*123-0.=+";
for(int i=0;i<16;i++){
bt[i]=new Button(str.substring(i,i+1));
add(bt[i]);
}
}
}。