简单计算器
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Calculator extends JFrame
{
JTextField windows;
JButton data0,data1,data2,data3,data4,data5,data6,data7,data8;
JButton data9,datajia,datajian,datacheng,datachu,dataequl,databack;
JButton clear;
JPanel pbutton;
InnerPolice police;
String data=" ";
double[] number=new double[10];
char[] signal=new char[10];
public Calculator()
{
windows=new JTextField(34); //设置显示窗口
//windows.setSize(20, 20);
windows.setEditable(false);
JPanel Pwindows=new JPanel();
Pwindows.add(windows);
data0=new JButton("0"); //定义按键以及字体
data0.setFont(new Font("宋体",Font.BOLD,30));
data1=new JButton("1");
data1.setFont(new Font("宋体",Font.BOLD,30));
data2=new JButton("2");
data2.setFont(new Font("宋体",Font.BOLD,30));
data3=new JButton("3");
data3.setFont(new Font("宋体",Font.BOLD,30));
data4=new JButton("4");
data4.setFont(new Font("宋体",Font.BOLD,30));
data5=new JButton("5");
data5.setFont(new Font("宋体",Font.BOLD,30));
data6=new JButton("6");
data6.setFont(new Font("宋体",Font.BOLD,30));
data7=new JButton("7");
data7.setFont(new Font("宋体",Font.BOLD,30));
data8=new JButton("8");
data8.setFont(new Font("宋体",Font.BOLD,30));
data9=new JButton("9");
data9.setFont(new Font("宋体",Font.BOLD,30));
datajia=new JButton("+");
datajia.setFont(new Font("宋体",Font.BOLD,30));
datajian=new JButton("-");
datajian.setFont(new Font("宋体",Font.BOLD,30));
datacheng=new JButton("*");
datacheng.setFont(new Font("宋体",Font.BOLD,30));
datachu=new JButton("/");
datachu.setFont(new Font("宋体",Font.BOLD,30));
dataequl=new JButton("=");
dataequl.setFont(new Font("宋体",Font.BOLD,30));
databack=new JButton("backspace");
databack.setFont(new Font("宋体",Font.BOLD,30));
clear=new JButton("删除");
clear.setFont(new Font("宋体",Font.BOLD,30));
//clear.setSize(100, 10);
//clear.addActionListener(police);
JPanel pclear=new JPanel();
pclear.add(clear);
pbutton=new JPanel(); //向容器中添加按钮
pbutton.setLayout(new GridLayout(4,4));
pbutton.add(data1);
pbutton.add(data2);
pbutton.add(data3);
pbutton.add(datajia);
pbutton.add(data4);
pbutton.add(data5);
pbutton.add(data6);
pbutton.add(datajian);
pbutton.add(data7);
pbutton.add(data8);
pbutton.add(data9);
pbutton.add(datacheng);
pbutton.add(data0);
pbutton.add(databack);
pbutton.add(dataequl);
pbutton.add(datachu);
setBounds(100,100,400,260);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(Pwindows,BorderLayout.NORTH);
add(pbutton,BorderLayout.CENTER);
add(pclear,BorderLayout.SOUTH);
police=new InnerPolice(); //添加监视器进行监视
data0.addActionListener(police);
data1.addActionListener(police);
data2.addActionListener(police);
data3.addActionListener(police);
data4.addActionListener(police);
data5.addActionListener(police);
data6.addActionListener(police);
data7.addActionListener(police);
data8.addActionListener(police);
data9.addActionListener(police);
datajia.addActionListener(police);
datajian.addActionListener(police);
datacheng.addActionListener(police);
datachu.addActionListener(police);
dataequl.addActionListener(police);
databack.addActionListener(police);
clear.addActionListener(police);
}
class InnerPolice implements ActionListener //监视器函数体
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==clear)
{
//System.out.println("hello world");
data=" ";
windows.setText(data);
}
if(e.getSource()==data0)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data1)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data2)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data3)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data4)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data5)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data6)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data7)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data8)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==data9)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==datajia)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==datajian)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==datacheng)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==datachu)
{
data+=e.getActionCommand();
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
if(e.getSource()==databack)
{
int lengthofdata=data.length();
if(lengthofdata==1)
;
else
lengthofdata--;
data=data.substring(0,lengthofdata);
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
//System.out.println(data);
}
if(e.getSource()==dataequl)
{
data+=e.getActionCommand();
windows.setText(data);
int n=data.length();
String memorial;
int fore=1,end,lengthofnumber=0,lengthofsignal=0;
double now;
for(int i=0;i<n;i++) //以运算符号作为标志，将数字以及运算符号分别入栈，并进行相应的处理
if(data.charAt(i)=='+'||data.charAt(i)=='-'||data.charAt(i)=='*'||data.charAt(i)=='/'||data.charAt(i)=='=')
{
end=i;
memorial=data.substring(fore, end); //将数字抽离出来
// System.out.println(fore+" "+end+" number:"+memorial+" signal:"+data.charAt(i));
number[lengthofnumber++]=Integer.parseInt(memorial); //将数字入栈
if(lengthofsignal==0) //第一次时，
{
signal[lengthofsignal++]=data.charAt(i);
//lengthofsignal++;
fore=i+1;
continue;
}
if(signal[lengthofsignal-1]=='*') //如果是乘法，则提前运算
{
now=number[--lengthofnumber]; //乘数出栈
double before=number[--lengthofnumber]; //被乘数出栈
now=before*now;
number[lengthofnumber++]=now; //运算结果进栈
lengthofsignal--; //符号栈减一
}
else if(signal[lengthofsignal-1]=='/') //如果是除法，则提前运算
{
now=number[--lengthofnumber]; //除数出栈
double before=number[--lengthofnumber]; //被除数出栈
now=before/now;
number[lengthofnumber++]=now; //运算结果进栈
lengthofsignal--; //符号栈减一
}
//System.out.println(number[lengthofnumber]);
signal[lengthofsignal]=data.charAt(i);
lengthofsignal++;
fore=i+1;
}
lengthofsignal--;
//System.out.println("lengthofnumber:"+lengthofnumber+" lengthofsignal:"+lengthofsignal);
//for(int i=0;i<lengthofnumber;i++)
//System.out.println("number["+i+"]"+number[i]);
//for(int i=0;i<lengthofsignal;i++)
//System.out.println("signal["+i+"]"+signal[i]);
//int k=0;
while(lengthofsignal!=0) //计算剩余加减法
{
//System.out.println("hello world"+lengthofsignal);
if(signal[lengthofsignal-1]=='-') //判断是否是减法
{
//System.out.println("test:"+lengthofsignal);
now=number[--lengthofnumber]; //减数出栈
double before=number[--lengthofnumber]; //被减数判断
now=before-now;
number[lengthofnumber++]=now; //将结果入栈
lengthofsignal--; //符号出栈
//System.out.println("values:"+now);
}
else if(signal[lengthofsignal-1]=='+') //判断是否是加法
{
//System.out.println("test:"+lengthofsignal);
now=number[--lengthofnumber]; //加数出栈
double before=number[--lengthofnumber]; //被加数出栈
now=before+now;
number[lengthofnumber++]=now; //将结果入栈
lengthofsignal--; //符号出栈
//System.out.println("values:"+now);
}
}
String values=""+number[0];
//System.out.println(values);
data+=values;
windows.setText(data);
windows.setFont(new Font("宋体",Font.BOLD,20));
}
}
}
public static void main(String[] args)
{
new Calculator();
}
}
结果：
