安卓开发 eclipse 计算器模型

怎么做在eclipse安卓 里制作一个计算器APP,在虚拟机里出现能实现加减乘除等简单的运算

给你一个以前写好的,仅供参考
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.text.DecimalFormat;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator {
//计算器面板
private JFrame f = new JFrame("Calculator");
//输入面扳
private JPanel inputPanel = new JPanel();
//加减乘除面板
private JPanel operationPanel = new JPanel();
//数字面板
private JPanel buttonsPanel = new JPanel();

//输入数据文本框
private JTextField input = new JTextField(20);

//退格键
private JButton backspace = new JButton("BackSpace");
//清空
private JButton CE = new JButton("CE  ");
//删除
private JButton C = new JButton("C  ");

//四则运算符号键
private JButton add = new JButton("+");
private JButton sub = new JButton("-");
private JButton mul = new JButton("*");
private JButton div = new JButton("/");

//小数点
private JButton decimal = new JButton(".");
//等号
private JButton equal = new JButton("=");

//数字键
private JButton zero = new JButton("0");
private JButton one = new JButton("1");
private JButton two = new JButton("2");
private JButton three = new JButton("3");
private JButton four = new JButton("4");
private JButton five = new JButton("5");
private JButton six = new JButton("6");
private JButton seven = new JButton("7");
private JButton eight = new JButton("8");
private JButton nine = new JButton("9");

private String num1 = "";//保存第一个运算数字
private String operator = "";//保存运算符号

public static void main(String[] args) {
    new Calculator();//new计算器实例
}

public Calculator(){
     //添加组件,布局
    inputPanel.add(input);
    f.add(inputPanel, BorderLayout.NORTH);

    operationPanel.add(backspace);
    operationPanel.add(CE);
    operationPanel.add(C);
    f.add(operationPanel, BorderLayout.CENTER);

    buttonsPanel.add(add);
    buttonsPanel.add(sub);
    buttonsPanel.add(mul);
    buttonsPanel.add(div);
    buttonsPanel.add(one);
    buttonsPanel.add(two);
    buttonsPanel.add(three);
    buttonsPanel.add(zero);
    buttonsPanel.add(four);
    buttonsPanel.add(five);
    buttonsPanel.add(six);
    buttonsPanel.add(decimal);
    buttonsPanel.add(seven);
    buttonsPanel.add(eight);
    buttonsPanel.add(nine);
    buttonsPanel.add(equal);
    buttonsPanel.setLayout(new GridLayout(4, 4));
    f.add(buttonsPanel, BorderLayout.SOUTH);

    //注册各个组件监听事件
    backspace.addMouseListener(new OperationMouseListener());
    CE.addMouseListener(new OperationMouseListener());
    C.addMouseListener(new OperationMouseListener());
    decimal.addMouseListener(new OperationMouseListener());
    equal.addMouseListener(new OperationMouseListener());

    //注册四则运算监听
    add.addMouseListener(new CalcMouseListener());
    sub.addMouseListener(new CalcMouseListener());
    mul.addMouseListener(new CalcMouseListener());
    div.addMouseListener(new CalcMouseListener());

    //注册数字监听事件
    zero.addMouseListener(new NumberMouseListener());
    one.addMouseListener(new NumberMouseListener());
    two.addMouseListener(new NumberMouseListener());
    three.addMouseListener(new NumberMouseListener());
    four.addMouseListener(new NumberMouseListener());
    five.addMouseListener(new NumberMouseListener());
    six.addMouseListener(new NumberMouseListener());
    seven.addMouseListener(new NumberMouseListener());
    eight.addMouseListener(new NumberMouseListener());
    nine.addMouseListener(new NumberMouseListener());

    f.setVisible(true);
    f.pack();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

private class NumberMouseListener implements MouseListener{

    public void mouseClicked(MouseEvent e) {
        if(input.getText().trim().equals("0")){//如果文本框已经是0,结果还是0
            input.setText(((JButton)e.getSource()).getText().trim());
        }else{//否则的话,把0添加到后面,譬如文本框是1,结果就为10
            input.setText(input.getText().concat(((JButton)e.getSource()).getText().trim()));
        }
    }

    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mousePressed(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}  
}

private class CalcMouseListener implements MouseListener{
    //如果输入的是运算符号,保存第一个结果和运算符号
    public void mouseClicked(MouseEvent e) {
        num1 = input.getText().trim();input.setText("");
        operator = ((JButton)e.getSource()).getText().trim();
    }

    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mousePressed(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}  
}

private class OperationMouseListener implements MouseListener{

    public void mouseClicked(MouseEvent e) {
        if(e.getSource() == backspace){//退格键,删除一个直到没有字符删除
            String inputText = input.getText();
            if(inputText.length() > 0){
                input.setText(inputText.substring(0, inputText.length() - 1));
            }
        }else if(e.getSource() == C){
            input.setText("0");//C,清空所有运算数字和符号
            num1 = "";
        }else if(e.getSource() == CE){
            input.setText("0");//CE-->将文本框置为0
        }else if(e.getSource() == decimal){
            String text = input.getText().trim();
            //如果按了小数点,如果文本框已经有小数点,不做任何操作,否则在结果后面加上小数点
            if(text.indexOf(".") == -1){
                input.setText(text.concat("."));
            }
        }else if(e.getSource() == equal){
            //如果是等号
            if(!operator.trim().equals("")){
                if(!input.getText().trim().equals("")){
                    double result = 0D;
                    if(operator.equals("+")){//执行加法运算
                        result = Double.parseDouble(num1) + Double.parseDouble(input.getText().trim());
                    }else if(operator.equals("-")){//减法运算
                        result = Double.parseDouble(num1) - Double.parseDouble(input.getText().trim());
                    }else if(operator.equals("*")){//乘法运算
                        result = Double.parseDouble(num1) * Double.parseDouble(input.getText().trim());
                    }else if(operator.equals("/")){//除法运算
                        result = Double.parseDouble(num1) / Double.parseDouble(input.getText().trim());
                    }

                     //格式化最终结果,保留两位小数点
                    input.setText(new DecimalFormat("0.00").format(result));
                }
            }

        }

    }

    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mousePressed(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}  
}

}

题主你百度一下“easyUI 计算器”