java模仿计算器 java简单模仿win10计算器

package com.waking.call;


import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;


/**
 * 计算器小案例
 * @author waking
 *
 */
public class CalculatorExample {

 public static void main(String[] args) {
 // TODO Auto-generated method stub
 CalculatorFrame calculatorFrame=new CalculatorFrame();
 }
}
class CalculatorFrame extends JFrame{
 public CalculatorFrame() {//构造函数
 setTitle("计算器");
 setSize(340,500);
 CalcultorPanel calcultorPanel=new CalcultorPanel();
 getContentPane().add(calcultorPanel);//给当前Frame添加面板
 setLocationRelativeTo(null);//居中
 setDefaultCloseOperation(EXIT_ON_CLOSE);
 setVisible(true);
 }
}
class CalcultorPanel extends JPanel{//主面板
 public static boolean start=true;//新数字键输入的开始
 public static String result="";//保存中间结果的参数
 public static String lastcommand="=";//记录上一个运算符
 public static boolean firstDigit = true;//输入第一个数
 public CalcultorPanel() { 
 setLayout(new BorderLayout());
 ShowPanel showPanel=new ShowPanel();
 BTNPanel btnPanel=new BTNPanel();
 add(showPanel, BorderLayout.NORTH);
 add(btnPanel,BorderLayout.CENTER);
 } 
}
class ShowPanel extends JPanel{//结果面板
 public static JLabel display1;
 public static JLabel display2;
 public ShowPanel() {
 display1=new JLabel("",SwingConstants.RIGHT);
 display2=new JLabel("0",SwingConstants.RIGHT);
 display1.setFont(new Font("黑体",Font.BOLD,30));
 display2.setFont(new Font("黑体",Font.BOLD,40));
 display1.setPreferredSize(new Dimension(300, 80));
 display2.setPreferredSize(new Dimension(300, 50));
 setLayout(new BorderLayout());
 add(display1,BorderLayout.NORTH);
 add(display2,BorderLayout.CENTER);
 }
} 
class BTNPanel extends JPanel{//按钮面板
 public BTNPanel() {
 setLayout(new GridLayout(6, 4));
 InsertAciton insertAciton=new InsertAciton();
 CommandAction commandAction=new CommandAction();
 addButton("%", commandAction);
 addButton("√", commandAction);
 addButton("pow", commandAction);
 addButton("1/x", commandAction);
 addButton("CE", commandAction);
 addButton("C", commandAction);
 addButton("<<", commandAction);
 addButton("/",commandAction);
 addButton("7",insertAciton);
 addButton("8",insertAciton);
 addButton("9",insertAciton);
 addButton("*",commandAction);
 addButton("4",insertAciton);
 addButton("5",insertAciton);
 addButton("6",insertAciton);
 addButton("-",commandAction);
 addButton("1",insertAciton);
 addButton("2",insertAciton);
 addButton("3",insertAciton);
 addButton("+",commandAction);
 addButton("+/-",commandAction);
 addButton("0",insertAciton);
 addButton(".",insertAciton);
 addButton("=",commandAction);
 
 }
 void addButton(String label,ActionListener actionListener) {//添加按钮
 JButton button=new JButton(label);
 button.setFont(new Font("黑体",Font.BOLD,15));
 button.addActionListener(actionListener);
 add(button);
 }
}
class InsertAciton implements ActionListener{//数字键按钮事件
 @Override
 
 public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 if(CalcultorPanel.start==true) {
 //清空文本
 ShowPanel.display1.setText("");
 ShowPanel.display2.setText("");
 CalcultorPanel.start=false;
 }
 if ("0123456789.".indexOf(e.getActionCommand()) >= 0) {
 if (CalcultorPanel.firstDigit) {
    // 输入的第一个数字
 if(e.getActionCommand().equals(".")) {//如果第一个是“.”
 ShowPanel.display2.setText("0.");
  }else if(e.getActionCommand().equals("0")) {//如果第一个是“0”
  ShowPanel.display2.setText("0");
  CalcultorPanel.firstDigit=true;
  return;
  }
  else ShowPanel.display2.setText(e.getActionCommand());
 }
 else if ((e.getActionCommand().equals(".")) && (ShowPanel.display2.getText().indexOf(".") < 0)) {
   // 输入的是小数点，并且之前没有小数点，则将小数点附在结果文本框的后面
 ShowPanel.display2.setText(ShowPanel.display2.getText() + ".");
  } 
  else //if(Double.parseDouble(ShowPanel.display2.getText())!=0) 
  if (!e.getActionCommand().equals(".")) {
   // 如果输入的不是小数点，则将数字附在结果文本框的后面
   ShowPanel.display2.setText(ShowPanel.display2.getText() + e.getActionCommand());
  }
  // 以后输入的肯定不是第一个数字了
 CalcultorPanel.firstDigit = false;
 }
 }
 
}
class CommandAction implements ActionListener{//功能事件

 public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 
 String string = e.getActionCommand();
 if(string.equals("CE")) {
 ShowPanel.display1.setText("");
 ShowPanel.display2.setText("0");
  }else if(string.equals("C")) {
   CalcultorPanel.start=true;//新数字键输入的开始
   CalcultorPanel.result="";//保存中间结果的参数
   CalcultorPanel.lastcommand="=";//记录上一个运算符
   CalcultorPanel.firstDigit = true;//输入第一个数
   ShowPanel.display1.setText("");
   ShowPanel.display2.setText("0");
  }else if(string.equals("<<")) {//退格
   ShowPanel.display1.setText("");
   String text=ShowPanel.display2.getText();
   int i = text.length();
    if (i > 0) {
     // 退格，将文本最后一个字符去掉
     text = text.substring(0, i - 1);
     if (text.length() == 0) {
      // 如果文本没有了内容，则初始化计算器的各种值
     ShowPanel.display2.setText("0");
     CalcultorPanel.firstDigit = true;
     CalcultorPanel.lastcommand = "=";
     } else {
      // 显示新的文本
     ShowPanel.display2.setText(text);
     }
    }
   } else if(string.equals("+/-")) {
   String a1=ShowPanel.display2.getText();
   ShowPanel.display1.setText("");
   if(a1.indexOf("-")==-1) {
   if(Double.parseDouble(a1)!=0)
   ShowPanel.display2.setText("-"+ShowPanel.display2.getText());
   }
   else {
   ZeroText(Double.parseDouble(a1)*-1);
   }
 CalcultorPanel.result=a1;
   }else{
   CalcultorPanel.start=true;//新数字键的输入
   if(CalcultorPanel.lastcommand.equals("=")) //做一次运算
 { 
 CalcultorPanel.result=ShowPanel.display2.getText(); //获取操作数1
 }
 else {
 if (CalcultorPanel.lastcommand.equals("%")) {
    // 百分号运算，除以100
 double a1=Double.parseDouble(CalcultorPanel.result);
 a1= a1 / 100;
 if (CalcultorPanel.result=="0.") //去除0.问题
  ShowPanel.display1.setText(0+"/100"+"=");
 else ShowPanel.display1.setText(CalcultorPanel.result+"/100=");
 ZeroText(a1);
 CalcultorPanel.result=a1+"";
   }else if (CalcultorPanel.lastcommand.equals("√")) {
    // 平方根运算
   double a1=Double.parseDouble(CalcultorPanel.result);
    a1 = Math.sqrt(a1);
    if(CalcultorPanel.result=="0.")//去除0.问题
    ShowPanel.display1.setText("√("+0+")"+"=");
    else ShowPanel.display1.setText("√"+"("+CalcultorPanel.result+")=");
    ZeroText(a1);
 CalcultorPanel.result=a1+"";
   }else if(CalcultorPanel.lastcommand.equals("pow")) {
   double a1=Double.parseDouble(CalcultorPanel.result);
   double a2=Double.parseDouble(ShowPanel.display2.getText());
   double s=Math.pow(a1,a2);
   if (CalcultorPanel.result=="0.") {//去除0.问题
  if(ShowPanel.display2.getText()=="0.")
  ShowPanel.display1.setText("pow("+0+","+0+")"+"=");
  else ShowPanel.display1.setText("pow("+0+","+ShowPanel.display2.getText()+")"+"=");
 }else if(ShowPanel.display2.getText()=="0.") {
  ShowPanel.display1.setText("pow("+CalcultorPanel.result+","+0+")"+"=");
 }else 
   ShowPanel.display1.setText("pow"+"("+CalcultorPanel.result+","+ShowPanel.display2.getText()+")=");
   ZeroText(s);
 CalcultorPanel.result=a1+"";
   }else if (CalcultorPanel.lastcommand.equals("1/x")) {
    // 倒数运算
   double a1=Double.parseDouble(CalcultorPanel.result);
    if (a1 == 0.0) {
     // 操作不合法
    ShowPanel.display2.setText("零没有倒数");
    } else {
    a1 = 1 / a1;
    ShowPanel.display1.setText("1"+"/"+CalcultorPanel.result+"=");
    ZeroText(a1);
  CalcultorPanel.result=a1+"";
    }
   } 
 else if(CalcultorPanel.lastcommand.equals("+")) {
 double a1=Double.parseDouble(CalcultorPanel.result);
 double a2=Double.parseDouble(ShowPanel.display2.getText());
 double s=a1+a2;
 if (CalcultorPanel.result=="0.") {//去除0.问题
  if(ShowPanel.display2.getText()=="0.")
  ShowPanel.display1.setText(0+"+"+0+"=");
  else ShowPanel.display1.setText(0+"+"+ShowPanel.display2.getText()+"=");
 }else if(ShowPanel.display2.getText()=="0.") {
  ShowPanel.display1.setText(CalcultorPanel.result+"+"+0+"=");
 }else 
 ShowPanel.display1.setText(CalcultorPanel.result+"+"+ShowPanel.display2.getText()+"=");
 ZeroText(s);
 CalcultorPanel.result=s+""; 
 }
 else if(CalcultorPanel.lastcommand.equals("-")) {
 double a1=Double.parseDouble(CalcultorPanel.result);
 double a2=Double.parseDouble(ShowPanel.display2.getText());
 double s=a1-a2;
 if (CalcultorPanel.result=="0.") {//去除0.问题
  if(ShowPanel.display2.getText()=="0.")
  ShowPanel.display1.setText(0+"-"+0+"=");
  else ShowPanel.display1.setText(0+"-"+ShowPanel.display2.getText()+"=");
 }else if(ShowPanel.display2.getText()=="0.") {
  ShowPanel.display1.setText(CalcultorPanel.result+"-"+0+"=");
 }else 
 ShowPanel.display1.setText(CalcultorPanel.result+"-"+ShowPanel.display2.getText()+"=");
 ZeroText(s);
 CalcultorPanel.result=s+""; 
 }else if(CalcultorPanel.lastcommand.equals("*")) {
 double a1=Double.parseDouble(CalcultorPanel.result);
 double a2=Double.parseDouble(ShowPanel.display2.getText());
 double s=a1*a2;
 if (CalcultorPanel.result=="0.") {//去除0.问题
  if(ShowPanel.display2.getText()=="0.")
  ShowPanel.display1.setText(0+"*"+0+"=");
  else ShowPanel.display1.setText(0+"*"+ShowPanel.display2.getText()+"=");
 }else if(ShowPanel.display2.getText()=="0.") {
  ShowPanel.display1.setText(CalcultorPanel.result+"*"+0+"=");
 }else 
 ShowPanel.display1.setText(CalcultorPanel.result+"*"+ShowPanel.display2.getText()+"=");
 ZeroText(s);
 CalcultorPanel.result=s+""; 
 }else if (CalcultorPanel.lastcommand.equals("/")) {
    // 除法运算
    // 如果当前结果文本框中的值等于0
 double a1=Double.parseDouble(CalcultorPanel.result);
 double a2=Double.parseDouble(ShowPanel.display2.getText());
    if (a2 == 0.0) {
     // 操作不合法
    ShowPanel.display2.setText("除数不能为零");
    } else {
    double s=a1/a2;
    if(CalcultorPanel.result=="0.")//去除0.问题
    ShowPanel.display1.setText(0+"/"+ShowPanel.display2.getText()+"=");
    else ShowPanel.display1.setText(CalcultorPanel.result+"/"+ShowPanel.display2.getText()+"=");
  ZeroText(s);
  CalcultorPanel.result=s+""; 
    }
   } 
 } CalcultorPanel.lastcommand=e.getActionCommand();//获取当前的运算符
 CalcultorPanel.firstDigit = true;
 }
} 
 public void ZeroText(double s) { 
 long t1;
 double t2;
 t1 = (long) s;
 t2 = s-t1;
 if (t2 == 0) {
 ShowPanel.display2.setText(String.valueOf(t1));
 } else {
 ShowPanel.display2.setText(String.valueOf(s));
 }   
 } 
}