用JAVA寫的一個只基於awt的計算器---比較簡陋，繼續加油！

//設計一個簡單的計算器，可以關閉窗口，有菜單，能夠實現+、-、*、/、百分號、根號、倒數運算


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(); //創建2個面板，用於放文本、按鈕
   
    
    Double num1;
    Double num2;
    String tmp;
    Double num;
    int i;

public void tt(){
f=new Frame("計算器");
t=new TextField(24);
Button[] b=new Button[name.length];
f.addWindowListener(this);//關閉窗口的功能

MenuBar m=new MenuBar();
Menu me1=new Menu("查看(V)");
Menu me2=new Menu("編輯(E)");
Menu me3=new Menu("幫助(H)");
MenuItem mt1=new MenuItem("控制檯");
MenuItem mt2=new MenuItem("控制檯2");
MenuItem mt3=new MenuItem("控制檯3");//設置菜單的功能
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]);//這裏是按鈕的佈局
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){}//實現關閉窗口
public void windowDeiconified(WindowEvent e){}
public void windowActivated(WindowEvent e){}
public void windowDeactivated(WindowEvent e){}


public void actionPerformed(ActionEvent e){//實現消息映射

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());//將標籤中的數字放入文本框中，並且是累加的，不然就只能存放一位數
   
   
   
    if(e.getActionCommand().equals("CE"))
    {
     t.setText(""); //如果按鈕是CE,那麼就講文本中內容置空
    }
    
    if(e.getActionCommand().equals("+")){
    tmp=t.getText();
    num=Double.parseDouble(tmp);//如果爲+，把之前文本框中的字符串轉換成爲數字，然後將文本框清空，以備存放下一個數字
    t.setText("");//-、*、/同理
    i=0; //做一個標記
    }
    
    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()+".");
    }
    
    //下面幾個就是單目運算了啦~
    
    if(e.getActionCommand().equals("sqrt")){
    tmp=t.getText();
    num1=Double.parseDouble(tmp);//把字符串轉成數字計算，再把計算出來的數字轉成字符串顯示到文本框
    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));
    }
    
  
    //最後是等於號
    
    if(e.getActionCommand().equals("=")||e.getActionCommand().equals("Enter")){
    tmp=t.getText();
    double num_after=Double.parseDouble(tmp);//這是把等於號之前，+號之後的字符串轉換成數字，因爲在+號的時候已經將前面內容清空了
    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("除數不能爲零！");
    }
    else{
    t.setText(Double.toString(num/num_after));
    }
    }
    }
    
  
   
    } 

public static void main(String args[]){
LittleCalculator p=new LittleCalculator();
p.tt();
}

}