calculator.java

Java写的计算器

package com.cn.dxj;

import javax.swing.*;

import java.awt.Color;
import java.awt.event.*;

class Calculator extends JFrame{
JButton J0,J1,J2,J3,J4,J5,J6,J7,J8,J9,Jdian,Jjia,Jjian,Jchen,Jchu,Jdeng,JC;
JTextField JTField1;
String Temp1;//存放前一个数
Double Temp2;//存放结果
int n;//判断使用哪种运算符
int count=1;//判断是否按过加减乘除,以便按运算符号的时候屏幕正确显示
int x=1;//判断小数点是否被按过
Double j;

public Calculator(){
  
   setBounds(300,300,400,400);//方框的大小
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
  
   J0=new JButton("0");//定义各个键
   J1=new JButton("1");
   J2=new JButton("2");
   J3=new JButton("3");
   J4=new JButton("4");
   J5=new JButton("5");
   J6=new JButton("6");
   J7=new JButton("7");
   J8=new JButton("8");
   J9=new JButton("9");
   Jdian=new JButton(".");
   Jjia=new JButton("+");
   Jjian=new JButton("-");
   Jchen=new JButton("*");
   Jchu=new JButton("/");
   Jdeng=new JButton("=");
   JC=new JButton("C");
   JTField1=new JTextField(0);
  
   getContentPane().setLayout(null);//显示各个数字键
  
   J0.setBounds(70,60,50,50);//确定各个键的位置
   J1.setBounds(120,60,50,50);
   J2.setBounds(170,60,50,50);
   J3.setBounds(70,110,50,50);
   J4.setBounds(120,110,50,50);
   J5.setBounds(170,110,50,50);
   J6.setBounds(70,160,50,50);
   J7.setBounds(120,160,50,50);
   J8.setBounds(170,160,50,50);
   J9.setBounds(70,210,50,50);
   Jdian.setBounds(120,210,50,50);
   Jjia.setBounds(220,60,50,50);
   Jjian.setBounds(220,110,50,50);
   Jchen.setBounds(220,160,50,50);
   Jchu.setBounds(220,210,50,50);
   Jdeng.setBounds(170,210,50,50);
   JC.setBounds(70,260,200,50);
   JTField1.setBounds(70,10,200,30);
   J0.setBackground(Color.black);
  
   getContentPane().add(J0); 
   getContentPane().add(J1); 
   getContentPane().add(J2); 
   getContentPane().add(J3); 
   getContentPane().add(J4);
   getContentPane().add(J5);
   getContentPane().add(J6);
   getContentPane().add(J7);
   getContentPane().add(J8);
   getContentPane().add(J9);
   getContentPane().add(Jdian);
   getContentPane().add(Jjia);
   getContentPane().add(Jjian);
   getContentPane().add(Jchen);
   getContentPane().add(Jchu);
   getContentPane().add(Jdeng);
   getContentPane().add(JC);
   getContentPane().add(JTField1);
  
   J0.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"0");
    else JTField1.setText("0");
    count=1;
    }}); //键入数字
   J1.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"1");
    else JTField1.setText("1");
    count=1;
    }}); 
   J2.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"2");
    else JTField1.setText("2");
    count=1;
    }}); 
   J3.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"3");
    else JTField1.setText("3");
    count=1;
    }}); 
   J4.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"4");
    else JTField1.setText("4");
    count=1;
    }}); 
   J5.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"5");
    else JTField1.setText("5");
    count=1;
    }}); 
   J6.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"6");
    else JTField1.setText("6");
    count=1;
    }}); 
   J7.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"7");
    else JTField1.setText("7");
    count=1;
    }}); 
   J8.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"8");
    else JTField1.setText("8");
    count=1;
    }}); 
   J9.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    if(count==1)
     JTField1.setText(JTField1.getText()+"9");
    else JTField1.setText("9");
    count=1;
    }}); 
   Jdian.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
     if(x==1)
     JTField1.setText(JTField1.getText()+".");
     x=0;//取消小数点的使用
    count=1;
    }}); 
  
   Jjia.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    count=0;
    x=1;//恢复小数点的使用
    n=1;
    Temp1=JTField1.getText();//储存按加号前的数字
    }}); 
   Jjian.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    count=0;
    x=1;//恢复小数点的使用
    n=2;
    Temp1=JTField1.getText();//储存按减号前的数字
    }}); 
   Jchen.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    count=0;
    x=1;//恢复小数点的使用
    n=3;
    Temp1=JTField1.getText();//储存按乘号前的数字
    }}); 
   Jchu.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    count=0;
    x=1;//恢复小数点的使用
    n=4;
    Temp1=JTField1.getText();//储存按除号前的数字
    }}); 
   Jdeng.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
     int s=JTField1.getText().length();
     if (s>0)
    {switch(n){//switch语句判断使用的是什么运算符号
    case 1: Temp2=Double.parseDouble(Temp1)+Double.parseDouble(JTField1.getText());break;
    case 2: Temp2=Double.parseDouble(Temp1)-Double.parseDouble(JTField1.getText());break;
    case 3: Temp2=Double.parseDouble(Temp1)*Double.parseDouble(JTField1.getText());break;
    case 4: Temp2=Double.parseDouble(Temp1)/Double.parseDouble(JTField1.getText());break;}
    JTField1.setText(Temp2+"");}
    }}); 
   JC.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent e){ 
    JTField1.setText("");
    }});
   setVisible(true); 
   setTitle("该计算器是网上找来经过修改而来!");
  //setResizable(false);
} 
public static void main(String[] args) { 
    Calculator x=new Calculator();//清零后等待下一次的输入
  
            } 
}