懂Java的朋友进来，请各位大虾帮忙啊

MyCalculator.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MyCalculator implements ActionListener
{
JFrame f;
JMenu mEdit;
JMenu mView;
JMenu mHelp;
JMenuItem mCopy;
JMenuItem mPaste;
JTextField tResult;

JButton bNumber;
JButton bOperator;
JButton bOther;
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 MyCalculator()
{
f = new JFrame("计算器ByMdou");
Container contentPane = f.getContentPane();
/****************菜单的创建开始**************************************/
JMenuBar mBar = new JMenuBar();
mBar.setOpaque(true);

mEdit = new JMenu("编辑(E)");
mEdit.setMnemonic(KeyEvent.VK_E);
mCopy = new JMenuItem("复制(C)");
mEdit.add(mCopy);
mPaste = new JMenuItem("粘贴(P)");
mEdit.add(mPaste);

mView = new JMenu("查看(V)");
mView.setMnemonic(KeyEvent.VK_V);
mView.add(new JMenuItem("标准型"));
mView.add(new JMenuItem("科学型"));
mView.addSeparator();
mView.add(new JMenuItem("查看分组"));

mHelp = new JMenu("帮助(H)");
mHelp.setMnemonic(KeyEvent.VK_H);
mHelp.add(new JMenuItem("帮助主题"));
mHelp.addSeparator();
mHelp.add(new JMenuItem("关于计算器"));

mBar.add(mEdit);
mBar.add(mView);
mBar.add(mHelp);
f.setJMenuBar(mBar);
contentPane.setLayout(new BorderLayout());
JPanel pTop = new JPanel();
tResult = new JTextField("0.",26);
tResult.setHorizontalAlignment(JTextField.RIGHT );
tResult.setEditable(false);
pTop.add(tResult);
contentPane.add(pTop,BorderLayout.NORTH);
JPanel pBottom = new JPanel();
pBottom.setLayout(new BorderLayout());
JPanel pLeft = new JPanel();
pLeft.setLayout(new GridLayout(5,1,3,3));
bM = new JButton(" ");

bM.setEnabled(false);
pLeft.add(bM);
bOther = new JButton("MC");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
bOther.setMargin(new Insets(3,2,3,2));
pLeft.add(bOther);
bOther = new JButton("MR");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
bOther.setMargin(new Insets(3,2,3,2));
pLeft.add(bOther);
bOther = new JButton("MS");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
bOther.setMargin(new Insets(3,2,3,2));
pLeft.add(bOther);
bOther = new JButton("M+");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
bOther.setMargin(new Insets(3,2,3,2));
pLeft.add(bOther);
pBottom.add(pLeft,BorderLayout.WEST);
JPanel pRight = new JPanel();
pRight.setLayout(new BorderLayout());
JPanel pUp = new JPanel();
pUp.setLayout(new GridLayout(1,3,3,0));
bOther = new JButton("Backspace");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
bOther.setMargin(new Insets(3,0,3,5));
pUp.add(bOther);
bOther = new JButton("CE");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
pUp.add(bOther);
bOther = new JButton("C");
bOther.addActionListener(this);
bOther.setForeground(Color.RED);
pUp.add(bOther);
JPanel pDown = new JPanel();
pDown.setLayout(new GridLayout(4,5,3,2));
bNumber = new JButton("7");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bNumber = new JButton("8");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bNumber = new JButton("9");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bOperator = new JButton("/");
bOperator.setForeground(Color.RED);
bOperator.addActionListener(this);

bOperator.setMargin(new Insets(3,0,3,0));
pDown.add(bOperator);
bOperator = new JButton("sqrt");
bOperator.addActionListener(this);
bOperator.setForeground(Color.blue);
bOperator.setMargin(new Insets(3,0,3,0));
pDown.add(bOperator);
bNumber = new JButton("4");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
bNumber.setHorizontalTextPosition(JButton.LEFT);
pDown.add(bNumber);
bNumber = new JButton("5");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bNumber = new JButton("6");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bOperator = new JButton("*");
bOperator.setForeground(Color.RED);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bOperator = new JButton("%");
bOperator.setForeground(Color.blue);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bNumber = new JButton("1");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bNumber = new JButton("2");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bNumber = new JButton("3");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bOperator = new JButton("-");
bOperator.setForeground(Color.RED);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bOperator = new JButton("1/x");
bOperator.setForeground(Color.blue);
bOperator.addActionListener(this);
pDown.add(bOperator);
bNumber = new JButton("0");
bNumber.setForeground(Color.blue);
bNumber.addActionListener(this);
bNumber.setMargin(new Insets(3,3,3,3));
pDown.add(bNumber);
bOperator = new JButton("+/-");
bOperator.setForeground(Color.blue);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bOperator = new JButton(".");
bOperator.setForeground(Color.blue);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bOperator = new JButton("+");
bOperator.setForeground(Color.RED);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
bOperator = new JButton("=");
bOperator.setForeground(Color.blue);
bOperator.addActionListener(this);
bOperator.setMargin(new Insets(3,3,3,3));
pDown.add(bOperator);
pRight.add(pUp,BorderLayout.NORTH);
pRight.add(pDown,BorderLayout.SOUTH);
pBottom.add(pRight,BorderLayout.EAST);
contentPane.add(pBottom,BorderLayout.SOUTH);
f.setSize(new Dimension(320,256));

f.setResizable(false);
f.setVisible(true);
f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
}
public void actionPerformed(ActionEvent e)
{
String s=e.getActionCommand();
if(s.equals("复制(C)"))
{
String temp=tResult.getText().trim();
copyBoard.replace(0,copyBoard.length(),temp);
mPaste.setEnabled(true);
}
else if(s.equals("粘贴(P)"))
{
tResult.setText(copyBoard.toString());
}
else if(s.equals("CE"))
{//如果是CE则清除文本框
tResult.setText("0.");
}
else if(s.equals("Backspace"))
{//如果是backspace则删除一个字符。
if(!tResult.getText().trim().equals("0."))
{ //如果文本框中有内容
if(str.length()!=1&&str.length()!=0)
{
tResult.setText(str.delete(str.length()-1,str.length()).toString());
}
else
{
tResult.setText("0.");
str.setLength(0);
}
}
op2=Double.parseDouble(tResult.getText().trim());
}
else if(s.equals("C"))
{//如果是C删除当前计算。
tResult.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
tResult.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=tResult.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=tResult.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置为它的倒数。
String temp=tResult.getText().trim();
double dtemp=Double.parseDouble(temp);
tResult.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=tResult.getText().trim();
double dtemp=Double.parseDouble(temp);
tResult.setText(""+Math.sqrt(dtemp));
}
else if(s.equals("+"))//+
{
str.setLength(0);
if(currentOp==0)
{
preOp=currentOp=1;//op1=0;
op2=0;
tResult.setText(""+op1);
}
else
{
currentOp =preOp;
preOp =1;
switch(currentOp){
case 1:op1=op1+op2;tResult.setText(""+op1);break;
case 2:op1=op1-op2;tResult.setText(""+op1);break;
case 3:op1=op1*op2;tResult.setText(""+op1);break;
case 4:op1=op1/op2;tResult.setText(""+op1);break;
}
}
}
else if(s.equals("-"))//-
{
str.setLength(0);
if(currentOp==0)
{
preOp=currentOp=2;//op1=op2;op2=0;
tResult.setText(""+op1);
}
else
{
currentOp =preOp;
preOp =2;
switch(currentOp){
case 1:op1=op1+op2;tResult.setText(""+op1);break;
case 2:op1=op1-op2;tResult.setText(""+op1);break;
case 3:op1=op1*op2;tResult.setText(""+op1);break;
case 4:op1=op1/op2;tResult.setText(""+op1);break;
}
}
}
else if(s.equals("*"))//*
{
str.setLength(0);
if(currentOp==0)
{
preOp=currentOp=3;//op1=op2;op2=1;
tResult.setText(""+op1);//op1=op2;
}
else
{
currentOp =preOp;
preOp =3;
switch(currentOp){
case 1:op1=op1+op2;tResult.setText(""+op1);break;
case 2:op1=op1-op2;tResult.setText(""+op1);break;
case 3:op1=op1*op2;tResult.setText(""+op1);break;
case 4:op1=op1/op2;tResult.setText(""+op1);break;
}
}
}
else if(s.equals("/"))// /
{
str.setLength(0);
if(currentOp==0)
{
preOp=currentOp=4;//op2=1;
tResult.setText(""+op1);//op1=op2;
}
else
{
currentOp =preOp;
preOp =4;
switch(currentOp){
case 1:op1=op1+op2;tResult.setText(""+op1);break;
case 2:op1=op1-op2;tResult.setText(""+op1);break;
case 3:op1=op1*op2;tResult.setText(""+op1);break;
case 4:op1=op1/op2;tResult.setText(""+op1);break;
}
}
}
else if(s.equals("="))// =
{
if(currentOp==0)
{
str.setLength(0);
tResult.setText(""+op2);
}
else
{
str.setLength(0);
currentOp =preOp;
switch(currentOp){
case 1:op1=op1+op2;tResult.setText(""+op1);break;
case 2:op1=op1-op2;tResult.setText(""+op1);break;
case 3:op1=op1*op2;tResult.setText(""+op1);break;
case 4:op1=op1/op2;tResult.setText(""+op1);break;
}
currentOp=0;
op2=0;
}
}
else if(s.equals("."))
{
isDouble=true;
if(tResult.getText().trim().indexOf('.')!=-1);
else
{
if(tResult.getText().trim().equals("0"))
{
str.setLength(0);
tResult.setText((str.append("0"+s)).toString());
}
//else if(tResult.getText().trim().equals("")){}//如果初时显示为空则不做任何操作
else
{
tResult.setText((str.append(s)).toString());
}
}
}
else if(s.equals("0"))//如果选择的是"0"这个数字键
{
if(tResult.getText().trim().equals("0.")){}
else
{
tResult.setText(str.append(s).toString());
op2=Double.parseDouble(tResult.getText().trim());
}
}
else
{
tResult.setText(str.append(s).toString());
op2=Double.parseDouble(tResult.getText().trim());
if(currentOp==0)
op1=op2;
}

}//end actionPerformed

public static void main(String[] args)
{
new MyCalculator();
}

}