用JAVA写的一个只基于awt的计算器---比较简陋，继续加油！

//设计一个简单的计算器，可以关闭窗口，有菜单，能够实现+、-、*、/、百分号、根号、倒数运算

import java.awt.*;

import java.awt.event.*;

import java.lang.Math.*;

public class LittleCalculator implements ActionListener,WindowListener{

Frame f;

TextField t;

Button b[];

String name[]={"7","8","9","sqrt","CE","4","5","6","%","1/x","1","2","3","*","/","0",".","=","-","+"};

Panel p1=new Panel();

Panel p2=new Panel(); //创建2个面板，用于放文本、按钮

Double num1;

Double num2;

String tmp;

Double num;

int i;

public void tt(){

f=new Frame("计算器");

t=new TextField(24);

Button[] b=new Button[name.length];

f.addWindowListener(this);//关闭窗口的功能

MenuBar m=new MenuBar();

Menu me1=new Menu("查看(V)");

Menu me2=new Menu("编辑(E)");

Menu me3=new Menu("帮助(H)");

MenuItem mt1=new MenuItem("控制台");

MenuItem mt2=new MenuItem("控制台2");

MenuItem mt3=new MenuItem("控制台3");//设置菜单的功能

mt1.addActionListener(this);

mt2.addActionListener(this);

mt3.addActionListener(this);

me1.add(mt1);

me2.add(mt2);

me3.add(mt3);

m.add(me1);

m.add(me2);

m.add(me3);

f.setMenuBar(m);

p1.add(t);

f.add(p1,BorderLayout.NORTH);

p2.setLayout(new GridLayout(4,5,2,2));

for(int i=0;i<name.length;i++){

b[i]=new Button(name[i]);//这里是按钮的布局

p2.add(b[i]);

}

f.add(p2,BorderLayout.CENTER);

for(int i=0;i<name.length;i++){

b[i].addActionListener(this);}

f.setBackground(Color.blue);

f.setSize(200,200);

f.setVisible(true);

}

public void windowClosing(WindowEvent e)

{System.exit(0);}

public void windowClosed(WindowEvent e){}

public void windowOpened(WindowEvent e){}

public void windowIconified(WindowEvent e){}//实现关闭窗口

public void windowDeiconified(WindowEvent e){}

public void windowActivated(WindowEvent e){}

public void windowDeactivated(WindowEvent e){}

public void actionPerformed(ActionEvent e){//实现消息映射

if(e.getActionCommand().equals("0")||e.getActionCommand().equals("1")||e.getActionCommand().equals("2")||e.getActionCommand().equals("3")||e.getActionCommand().equals("4")||e.getActionCommand().equals("5")||e.getActionCommand().equals("6")||e.getActionCommand().equals("7")||e.getActionCommand().equals("8")||e.getActionCommand().equals("9"))

t.setText(t.getText()+e.getActionCommand());//将标签中的数字放入文本框中，并且是累加的，不然就只能存放一位数

if(e.getActionCommand().equals("CE"))

{

t.setText(""); //如果按钮是CE,那么就讲文本中内容置空

}

if(e.getActionCommand().equals("+")){

tmp=t.getText();

num=Double.parseDouble(tmp);//如果为+，把之前文本框中的字符串转换成为数字，然后将文本框清空，以备存放下一个数字

t.setText("");//-、*、/同理

i=0;
//做一个标记

}

if(e.getActionCommand().equals("-")){

tmp=t.getText();

num=Double.parseDouble(tmp);

t.setText("");

i=1;

}

if(e.getActionCommand().equals("*")){

tmp=t.getText();

num=Double.parseDouble(tmp);

t.setText("");

i=2;

}

if(e.getActionCommand().equals("/")){

tmp=t.getText();

num=Double.parseDouble(tmp);

t.setText("");

i=3;

}

if(e.getActionCommand().equals(".")){

t.setText(t.getText()+".");

}

//下面几个就是单目运算了啦~

if(e.getActionCommand().equals("sqrt")){

tmp=t.getText();

num1=Double.parseDouble(tmp);//把字符串转成数字计算，再把计算出来的数字转成字符串显示到文本框

num2=Math.sqrt(num1);//%、1/x同理

t.setText(Double.toString(num2));

}

if(e.getActionCommand().equals("%")){

tmp=t.getText();

num1=Double.parseDouble(tmp);

num2=num1/100;

t.setText(Double.toString(num2));

}

if(e.getActionCommand().equals("1/x")){

tmp=t.getText();

num1=Double.parseDouble(tmp);

num2=1/num1;

t.setText(Double.toString(num2));

}

//最后是等于号

if(e.getActionCommand().equals("=")||e.getActionCommand().equals("Enter")){

tmp=t.getText();

double num_after=Double.parseDouble(tmp);//这是把等于号之前，+号之后的字符串转换成数字，因为在+号的时候已经将前面内容清空了

if(i==0){

t.setText(Double.toString(num+num_after));

}

if(i==1){

t.setText(Double.toString(num-num_after));

}

if(i==2){

t.setText(Double.toString(num*num_after));

}

if(i==3){

if(num_after==0){

t.setText("");

System.out.println("除数不能为零！");

}

else{

t.setText(Double.toString(num/num_after));

}

}

}

}

public static void main(String args[]){

LittleCalculator p=new LittleCalculator();

p.tt();

}

}