这里写自定义目录标题
1.运行结果显示
实现了简单两位数的加减乘除运算，点击清空可继续下一次的输入
2.代码的实现
一些代码的注释都在代码里面
package cal;import java.awt.BorderLayout;import java.awt.EventQueue;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.border.EmptyBorder;import javax.swing.JTextField;import javax.swing.JButton;import java.awt.event.ActionListener;import java.awt.event.ActionEvent;public class JuanQi extends JFrame {private JPanel contentPane;private JTextField textField;private JTextField textField_1;private JTextField textField_2;private JTextField textField_3;private JTextField textField_4;/*** Launch the application.*/public static void main(String[] args) {EventQueue.invokeLater(new Runnable() {public void run() {try {JuanQi frame = new JuanQi();frame.setVisible(true);} catch (Exception e) {e.printStackTrace();}}});}/*** Create the frame.*/public JuanQi() {setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setBounds(100, 100, 450, 300);contentPane = new JPanel();contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));setContentPane(contentPane);contentPane.setLayout(null);textField = new JTextField();textField.setBounds(29, 25, 66, 21);contentPane.add(textField);textField.setColumns(10);textField_1 = new JTextField();textField_1.setBounds(105, 25, 35, 21);contentPane.add(textField_1);textField_1.setColumns(10);textField_2 = new JTextField();textField_2.setBounds(150, 25, 66, 21);contentPane.add(textField_2);textField_2.setColumns(10);textField_3 = new JTextField("=");textField_3.setBounds(226, 25, 35, 21);contentPane.add(textField_3);textField_3.setColumns(10);textField_4 = new JTextField();textField_4.setBounds(271, 25, 66, 21);contentPane.add(textField_4);textField_4.setColumns(10);JButton btnNewButton = new JButton("\u8BA1\u7B97");btnNewButton.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {try{if(textField_1.getText().equals("+"))//输入的是加号{//1. 因为从文本框得到的是String类型，不可以进行加减运算的操作// 使用Integer.parseInt将字符串转化为int类型进行运算//2.setText传入的是字符串，要将刚才转换计算过后的内容再转换回字符串// String.valueOf函数将int类型转换为String类型textField_4.setText((String.valueOf(Integer.parseInt(textField.getText())+Integer.parseInt(textField_2.getText()))));}if(textField_1.getText().equals("-"))//输入的是减号{textField_4.setText((String.valueOf(Integer.parseInt(textField.getText())-Integer.parseInt(textField_2.getText()))));}if(textField_1.getText().equals("*"))//输入的是乘号{textField_4.setText((String.valueOf(Integer.parseInt(textField.getText())*Integer.parseInt(textField_2.getText()))));}if(textField_1.getText().equals("/"))//输入的是除号{textField_4.setText((String.valueOf(Integer.parseInt(textField.getText())/Integer.parseInt(textField_2.getText()))));}}catch(Exception ee){System.out.println("\t捕获异常："+ee+"\n");}finally{//通常使用用来关闭资源代码}}});btnNewButton.setBounds(43, 109, 97, 23);contentPane.add(btnNewButton);JButton btnNewButton_1 = new JButton("\u6E05\u7A7A");btnNewButton_1.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {//清空按钮的事件textField.setText("");//将文本框里面的内容置空，方便下一次的输入textField_1.setText("");textField_2.setText("");textField_4.setText("");}});btnNewButton_1.setBounds(226, 109, 97, 23);contentPane.add(btnNewButton_1);}protected char[] Integer(String text) {// TODO Auto-generated method stubreturn null;}}
