简单计算器（Java_图形用户界面设计）

题目

编写一个应用程序，包括三个文本框和四个按钮，分别是“加”、“减”、“乘”、“除”，单击相应的按钮，将两个文本框的数字做运算，在第三个文本框中显示结果。

布局

Code

package unit_9;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.math.BigInteger;

public class p10_3 {
    public static void main(String[] args){
        WindowBox win=new WindowBox("cal");
    }
}
class WindowBox extends JFrame implements ActionListener {
    Box box11, box12, box13, box21, box22;
    JTextField text1,text2, text3;
    JButton button1, button2, button3, button4;
    WindowBox(String s){
        setTitle(s);
        text1=new JTextField(10);
        text2=new JTextField(10);
        text3=new JTextField(10);
        button1=new JButton("加");
        button2=new JButton("减");
        button3=new JButton("乘");
        button4=new JButton("除");
        text1.addActionListener(this);
        text2.addActionListener(this);
        text3.addActionListener(this);
        button1.addActionListener(this);
        button2.addActionListener(this);
        button3.addActionListener(this);
        button4.addActionListener(this);
        box11=Box.createVerticalBox();
        box11.add(new JLabel("number_1:"));
        box11.add(Box.createVerticalStrut(8));
        box11.add(new JLabel("number_2:"));
        box11.add(Box.createVerticalStrut(8));
        box11.add(new JLabel("ansewr:"));
        box12=Box.createVerticalBox();
        box12.add(text1);
        box12.add(Box.createVerticalStrut(8));
        box12.add(text2);
        box12.add(Box.createVerticalStrut(8));
        box12.add(text3);
        box13=Box.createHorizontalBox();
        box13.add(box11);
        box13.add(Box.createHorizontalStrut(10));
        box13.add(box12);
        box21=Box.createHorizontalBox();
        box21.add(button1);
        box21.add(Box.createHorizontalStrut(8));
        box21.add(button2);
        box21.add(Box.createHorizontalStrut(8));
        box21.add(button3);
        box21.add(Box.createHorizontalStrut(8));
        box21.add(button4);
        box22=Box.createVerticalBox();
        box22.add(box13);
        box22.add(Box.createVerticalStrut(20));
        box22.add(box21);
        setLayout(new FlowLayout());
        add(box22);
        validate();
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setVisible(true);
        setBounds(700, 300, 300, 200);
    }
    public void actionPerformed(ActionEvent e){
        String val1="", val2="";
        try{
        if(e.getSource()==button1)
        {
            val1=text1.getText();
            val2=text2.getText();
            BigInteger n1=new BigInteger(val1);
            BigInteger n2=new BigInteger(val2);
            n2=n1.add(n2);
            text3.setText(n2.toString());
        }
        else if(e.getSource()==button2)
        {
            val1=text1.getText();
            val2=text2.getText();
            BigInteger n1=new BigInteger(val1);
            BigInteger n2=new BigInteger(val2);
            n2=n1.subtract(n2);
            text3.setText(n2.toString());
        }
        else if(e.getSource()==button3)
        {
            val1=text1.getText();
            val2=text2.getText();
            BigInteger n1=new BigInteger(val1);
            BigInteger n2=new BigInteger(val2);
            n2=n1.multiply(n2);
            text3.setText(n2.toString());
        }
        else if(e.getSource()==button4)
        {
            val1=text1.getText();
            val2=text2.getText();
            double v1=Double.parseDouble(val1);
            double v2=Double.parseDouble(val2);
            if(v2==0)
                text2.setText("分母不能为0！");
            else{
                v2=v1/(v2*1.0);
                text3.setText(Double.toString(v2));
            }
        }
        }catch(NumberFormatException ee) {
            text3.setText("请输入数字字符");
            text1.setText(null);
            text2.setText(null);
        }
    }
}

结果展示