java：calc

版权声明：java洪君 https://blog.csdn.net/qq_43532342/article/details/85850760

package com.hc.calc;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;
import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;

public class Calc extends JFrame{

	
	JPanel jp=new JPanel();
	JLabel jl=new JLabel("第一个数");
	JTextField jt=new JTextField(25);
	JLabel jls=new JLabel("第二个数");
	JTextField jts=new JTextField(25);
	
	JButton add=new JButton("+");
	JButton subtract=new JButton("-");
	JButton multiply=new JButton("x");
	JButton divide=new JButton("/");

	JButton jbreturn=new JButton("退出");
	
	public static void main(String[] args) throws Exception {
			UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
			new Calc();
	}

	public Calc() {
		this.setSize(250, 300);
		this.setTitle("calc");
		this.setLocationRelativeTo(null);
		this.setDefaultCloseOperation(3);
		
		jp.add(jl);
		jp.add(jt);
		
		jp.add(jls);
		jp.add(jts);
		
		jp.add(add);
		jp.add(subtract);
		jp.add(multiply);
		jp.add(divide);
		
		jp.add(jbreturn);
		
		jbreturn.addActionListener(new ActionListener() {
			
			public void actionPerformed(ActionEvent e) {
				int i=JOptionPane.showConfirmDialog(null, "确定退出？");
				if (i==0) {
					Calc.this.dispose();
				}
			}
		});
		
		add.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
			jt.setText(new BigDecimal(jt.getText()).add(new BigDecimal(jts.getText())).stripTrailingZeros().toPlainString());
			jts.setText("");
			}
		});

		subtract.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
			jt.setText(new BigDecimal(jt.getText()).subtract(new BigDecimal(jts.getText())).stripTrailingZeros().toPlainString());
			jts.setText("");
			}
		});

		multiply.addActionListener(new ActionListener() {
	
	@Override
	public void actionPerformed(ActionEvent e) {
	jt.setText(new BigDecimal(jt.getText()).multiply(new BigDecimal(jts.getText())).stripTrailingZeros().toPlainString());
	jts.setText("");
	}

		});

		divide.addActionListener(new ActionListener() {
	
	@Override
	public void actionPerformed(ActionEvent e) {
		MathContext mc=new MathContext(12,RoundingMode.HALF_DOWN);
	jt.setText(new BigDecimal(jt.getText()).divide(new BigDecimal(jts.getText()),mc).stripTrailingZeros().toPlainString());
	jts.setText("");
	}

		});
		
		this.getContentPane().add(jp);
		this.setVisible(true);
	}
	
}