From 7dd0d19f0b390bbea6dd0db263a70994eb6383cb Mon Sep 17 00:00:00 2001 From: ASUS Date: Thu, 10 Jun 2021 20:14:29 +0800 Subject: [PATCH] =?UTF-8?q?=E6=9C=80=E6=96=B0=E4=B8=80=E6=AC=A1=E6=8F=90?= =?UTF-8?q?=E4=BA=A4?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- src/java2020spring/Test.java | 317 ++++++++++++++++++++++++++++++++++- 1 file changed, 311 insertions(+), 6 deletions(-) diff --git a/src/java2020spring/Test.java b/src/java2020spring/Test.java index fc09c19..713d060 100644 --- a/src/java2020spring/Test.java +++ b/src/java2020spring/Test.java @@ -1,10 +1,315 @@ package java2020spring; - -public class Test { - + +import java.awt.Color; +import java.awt.Font; +import java.awt.event.ActionEvent; +import java.awt.event.ActionListener; + +import javax.swing.JButton; +import javax.swing.JFrame; +import javax.swing.JTextField; +import javax.swing.border.LineBorder; + +/** + * 计算器 + * @author Administrator + * 代码流程: + * 1.初始化窗口属性 + * 2.添加显示框 + * 3.添加按钮 + * 4.自定义数字按钮事件监听器 + * 5.自定义运算符按钮事件监听器 + * 6.自定义等号按钮事件监听器 + */ +public class Test extends JFrame{ + private static final long serialVersionUID = 1L; + private JTextField showView = null; + private NumberBtnActionListener numberBtnActionListener; + private LogicBtnActionListener logicBtnActionListener; + private String logic;//记录运算符的字符串 + private String content1 = "";//记录第一个数字的字符串 + private String content2 = "";//记录第二个数字的字符串 + + + /** + * 一些窗口的初始化操作,放入构造器中(封装思想) + */ + public Test() { + //窗口标题 + //思考: 调用方法时没有对象来调用 怎么回事?? + setTitle("java计算器"); + //窗口位置和大小 + //需要注意的是 这个坐标是相对于桌面 在桌面的哪个位置出现 + setBounds(300,150,220, 320); + //设置窗口右上角 关闭按钮的事件 + //点击时关闭 + setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); + //不能改变大小 + setResizable(false); + + //设置窗口布局为null 不设置窗口布局 + setLayout(null); + /** + * 重点: 调用方法,往窗口中添加显示框 + */ + addView(); + + /** + * 重点:调用方法,往窗口中添加按钮 + */ + addButton(); + + //对象创建完成时,显示窗口 + setVisible(true); + } + /** + * 窗口中添加按钮的方法 + */ + private void addButton() { + numberBtnActionListener = new NumberBtnActionListener(); + logicBtnActionListener = new LogicBtnActionListener(); + JButton button_7 = new JButton("7"); + button_7.setBounds(5,65,40,40); + //设置按钮边框为 浅灰色 厚度为1 + button_7.setBorder(new LineBorder(Color.lightGray,1)); + button_7.addActionListener(numberBtnActionListener); + add(button_7); + + JButton button_8 = new JButton("8"); + button_8.setBounds(60,65,40,40); + button_8.setBorder(new LineBorder(Color.lightGray,1)); + button_8.addActionListener(numberBtnActionListener); + add(button_8); + + JButton button_9 = new JButton("9"); + button_9.setBounds(115,65,40,40); + button_9.setBorder(new LineBorder(Color.lightGray,1)); + button_9.addActionListener(numberBtnActionListener); + add(button_9); + + JButton button_add = new JButton("+"); + button_add.setBounds(170,65,40,40); + button_add.setBorder(new LineBorder(Color.lightGray,1)); + button_add.addActionListener(logicBtnActionListener); + add(button_add); + + JButton button_4 = new JButton("4"); + button_4.setBounds(5,120,40,40); + //设置按钮边框为 浅灰色 厚度为1 + button_4.setBorder(new LineBorder(Color.lightGray,1)); + button_4.addActionListener(numberBtnActionListener); + add(button_4); + + JButton button_5 = new JButton("5"); + button_5.setBounds(60,120,40,40); + button_5.setBorder(new LineBorder(Color.lightGray,1)); + button_5.addActionListener(numberBtnActionListener); + add(button_5); + + JButton button_6 = new JButton("6"); + button_6.setBounds(115,120,40,40); + button_6.setBorder(new LineBorder(Color.lightGray,1)); + button_6.addActionListener(numberBtnActionListener); + add(button_6); + + JButton button_sub = new JButton("-"); + button_sub.setBounds(170,120,40,40); + button_sub.setBorder(new LineBorder(Color.lightGray,1)); + button_sub.addActionListener(logicBtnActionListener); + add(button_sub); + + + JButton button_1 = new JButton("1"); + button_1.setBounds(5,175,40,40); + //设置按钮边框为 浅灰色 厚度为1 + button_1.setBorder(new LineBorder(Color.lightGray,1)); + button_1.addActionListener(numberBtnActionListener); + add(button_1); + + JButton button_2 = new JButton("2"); + button_2.setBounds(60,175,40,40); + button_2.setBorder(new LineBorder(Color.lightGray,1)); + button_2.addActionListener(numberBtnActionListener); + add(button_2); + + JButton button_3 = new JButton("3"); + button_3.setBounds(115,175,40,40); + button_3.setBorder(new LineBorder(Color.lightGray,1)); + button_3.addActionListener(numberBtnActionListener); + add(button_3); + + JButton button_mul = new JButton("*"); + button_mul.setBounds(170,175,40,40); + button_mul.setBorder(new LineBorder(Color.lightGray,1)); + button_mul.addActionListener(logicBtnActionListener); + add(button_mul); + + + JButton button_0 = new JButton("0"); + button_0.setBounds(5,230,40,40); + //设置按钮边框为 浅灰色 厚度为1 + button_0.setBorder(new LineBorder(Color.lightGray,1)); + button_0.addActionListener(numberBtnActionListener); + add(button_0); + + JButton button_eq = new JButton("="); + button_eq.setBounds(60,230,40,40); + button_eq.setBorder(new LineBorder(Color.lightGray,1)); + button_eq.addActionListener(new EqBtnActionListener()); + add(button_eq); + + JButton button_c = new JButton("c"); + button_c.setBounds(115,230,40,40); + button_c.setBorder(new LineBorder(Color.lightGray,1)); + button_c.addActionListener(new CleanBtnActionListener()); + add(button_c); + + JButton button_div = new JButton("/"); + button_div.setBounds(170,230,40,40); + button_div.setBorder(new LineBorder(Color.lightGray,1)); + button_div.addActionListener(logicBtnActionListener); + add(button_div); + + + } + /** + * 往窗口添加显示框的方法 + */ + private void addView() { + //先添加显示框 只读编辑框 默认显示0 所以直接在构造器中 传入0 注意 传入的是字符串才能显示 + //这里使用成员变量的原因是:在按钮的事件监听器中需要使用显示框变量,所有使用成员变量来保存这个显示框,其他方法才能访问 + showView = new JTextField("0"); + //需要注意,这里的坐标是相对于窗口内部,而不再是桌面。 + showView.setBounds(5, 5, 205, 55); + showView.setHorizontalAlignment(JTextField.RIGHT); + //设置是否可编辑 设置只读 + showView.setEditable(false); + //设置背景色 + showView.setBackground(new Color(192, 192, 192)); + //设置字体 粗细 大小 + showView.setFont(new Font("Cambria", Font.BOLD, 16)); + add(showView); + } public static void main(String[] args) { - System.out.println("Hello world!"); - + new Test(); + } + /** + * 使用内部类实现事件监听器接口 + * 数字按钮监听器 + * 此监听器需要做的事 + * 1.获取按钮内容 + * 2.拼接字符串 + * 3.保存到第一个数字字符串成员变量 + * 3.转换为数字 + * 4.设置到显示框 + * 添加了运算符按钮之后增加的操作 + * 6.判断运算符有没有被点击 + * 7.如果点击了 将拼接的字符串保存到第二个数字字符串变量中 + */ + class NumberBtnActionListener implements ActionListener{ + public void actionPerformed(ActionEvent e) { + + //2.获取按钮内容 + JButton btn = (JButton)e.getSource(); + String btn_text = btn.getText(); + if (logic!=null&&!"".equals(logic)) { + //3.拼接字符串 + content2=content2+btn_text; + //4.转换为数字 + int number = Integer.valueOf(content2); + //5.设置到显示框 + showView.setText(number+""); + }else { + //3.拼接字符串 + content1=content1+btn_text; + //4.转换为数字 + int number = Integer.valueOf(content1); + //5.设置到显示框 + showView.setText(number+""); + } + } + + } + /** + * 清空按钮事件监听器 + * 1.设置显示框内容为空 + * 2.清空数字字符串 + * 3.清空运算符字符串 + */ + class CleanBtnActionListener implements ActionListener{ + public void actionPerformed(ActionEvent e) { + //1.设置显示框内容为空 + showView.setText("0"); + //2.清空操作 + content1 = ""; + content2 = ""; + logic = ""; + } + + } + + /** + * 运算符按钮事件监听器 + * + * 点击运算符按钮是判断计算器前后两个数字的临界点（临界操作） + * 也就是说,点击运算符按钮后,需要将运算符保存,供数字按钮监听器中判断 + * 1.获取运算符符号 + * 2.保存到成员变量中(为什么要保存到成员变量中) + */ + class LogicBtnActionListener implements ActionListener{ + + public void actionPerformed(ActionEvent e) { + //1.获取运算符内容 + JButton btn = (JButton)e.getSource(); + String logic = btn.getText(); + //2.保存到成员变量中 因为成员变量与这个局部变量名字相同,且this代表的是当前监听器对象,所有使用CalcFrame中this + Test.this.logic = logic; + } + + } + /** + * 等号按钮事件监听器 + * 1.将数字字符串1转换为数字 + * 2.将数字字符串2转换为数字 + * 3.对运算符进行判断和运算 + * 4.显示框显示内容 + * 5.清空两个数字字符串和运算符 + * @author Administrator + * + */ + class EqBtnActionListener implements ActionListener{ + public void actionPerformed(ActionEvent e) { + if (content1!=null&&!"".equals(content1)&&content2!=null&&!"".equals(content2)&&logic!=null&&!"".equals(logic)) { + //1.将数字字符串1转换为数字 + Integer number1 = Integer.valueOf(content1); + //2.将数字字符串2转换为数字 + Integer number2 = Integer.valueOf(content2); + //3.判断运算符 + String content = ""; + switch (logic) { + case "+": + content = (number1+number2)+""; + break; + case "-": + content = (number1-number2)+""; + break; + case "*": + content = (number1*number2)+""; + break; + case "/": + content = (new Double(number1)/new Double(number2))+""; + break; + default: + break; + } + //4.显示框显示最终结果 + showView.setText(content); + //5.清空操作 + content1 = ""; + content2 = ""; + logic = ""; + } + } + } - } -- Gitee