calculator.java

用JAVA编写的简单计算器程序,功能与电脑自带的功能相仿

import java.awt.*;
import java.awt.event.*;
public class Calculator extends Frame implements ActionListener {
private Button add,jian,chen,chu,percent,deng,clear;
public TextField f1;
public Calculator(){
   super(" 我的计算器 ");
   setLayout(new GridLayout(3,3));
   //setLayout(new FlowLayout(FlowLayout.CENTER,15,15));
    TextField f1=new TextField();
   f1.setText("");//没发挥作用?
   clear=new Button("clear");
   clear.addActionListener(this);
   add=new Button("+");
   add.addActionListener(this);
   jian=new Button("-");
   jian.addActionListener(this);
   chen=new Button("*");
   chen.addActionListener(this);
   chu=new Button("/");
   chu.addActionListener(this);
   percent=new Button("%");
   percent.addActionListener(this);
   deng=new Button("=");
   deng.addActionListener(this);  
   add(f1);add(clear);
   add(chu);add(jian);add(percent);
   add(add);add(chen);add(deng);
}
public void actionPerformed(ActionEvent e)
{
   String temp,temp1,temp2,temp3;
   Double shu1=0.0,shu2=0.0,shu3=0.0;
   int com;
   System.out.println(e.getActionCommand());
   temp=e.getActionCommand();
   if("clear".equals(temp)){f1.setText("");}//没发挥作用?
   else{
   if("=".equals(temp)){
   temp1=f1.getText();
    if(temp1.contains("+")){
    com=temp1.indexOf("+");
    shu1=Double.parseDouble(temp1.substring(0,com));
    shu2=Double.parseDouble(temp1.substring(com+1));
    shu3=shu1+shu2;
    temp3=Double.toString(shu3);
    f1.setText(temp3);
      }else if(temp1.contains("*")){
     com=temp1.indexOf("*");
     shu1=Double.parseDouble(temp1.substring(0,com));//初始化变量 shu1
     shu2=Double.parseDouble(temp1.substring(com+1));
     shu3=shu1*shu2;
     temp3=Double.toString(shu3);
     f1.setText(temp3);
     }else if(temp1.contains("/")){
      com=temp1.indexOf("/");
      shu1=Double.parseDouble(temp1.substring(0,com));
      shu2=Double.parseDouble(temp1.substring(com+1));
      shu3=shu1/shu2;
      temp3=Double.toString(shu3);
      f1.setText(temp3);
     }else if(temp1.contains("-")){
    com=temp1.indexOf("-");
    shu1=Double.parseDouble(temp1.substring(0,com));
    shu2=Double.parseDouble(temp1.substring(com+1));
    shu3=shu1-shu2;
    temp3=Double.toString(shu3);
    f1.setText(temp3);
     }else if(temp1.contains("%")){
    com=temp1.indexOf("%");
    shu1=Double.parseDouble(temp1.substring(0,com));
    shu2=Double.parseDouble(temp1.substring(com+1));
    shu3=shu1%shu2;
    temp3=Double.toString(shu3);
    f1.setText(temp3);
    }
   }else{
    temp2=f1.getText();
    temp2=temp2+temp;
    f1.setText(temp2);
   }
}
}
public static void main(String[] args){	
Frame  cal =new  Calculator();
cal.setSize(300,200);
  cal.setVisible(true);
}
}