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wjy 5 months ago
parent dd0a5dc1e1
commit 8fae370d03
1 changed files with 51 additions and 47 deletions
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src/computer/a.java
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@ -4,87 +4,93 @@ import javax.swing.*;
import java.awt.*; import java.awt.*;
import java.awt.event.ActionEvent; import java.awt.event.ActionEvent;
import java.awt.event.ActionListener; import java.awt.event.ActionListener;
import java.text.MessageFormat;
import java.util.Arrays;
public class a { public class a {
public static void main(String[] args) { public static void main(String[] args) {
JS win = new JS(); JS frame = new JS();
} }
} }
class JS extends JFrame implements ActionListener { class JS extends JFrame implements ActionListener {
private StringBuilder sBuilder = new StringBuilder(); // 利用StringBuilder类来显示，以及区分两个操作数 private final StringBuilder sBuilder = new StringBuilder();
JTextArea text = new JTextArea(); JTextArea text = new JTextArea();
double a, b; double a, b;
Double sum; Double sum;
String lastOperator = "="; String lastOperator = "=";
public JS() { public JS() {
setBounds(100, 100, 400, 400); setBounds(100, 100, 400, 400);
setTitle("计算器"); setTitle("计算器");
JMenuBar menubar = new JMenuBar(); // 创建菜单条 JMenuBar menubar = new JMenuBar();
this.setJMenuBar(menubar); // 将设置好的菜单条放在窗口中 this.setJMenuBar(menubar);
this.setLayout(new BorderLayout()); // 添加文本框 this.setLayout(new BorderLayout());
JPanel p1 = new JPanel(); JPanel p1 = new JPanel();
JPanel p2 = new JPanel(); JPanel p2 = new JPanel();
text.setPreferredSize(new Dimension(370, 60)); // 设置组件大小 text.setPreferredSize(new Dimension(370, 60));
p2.setLayout(new FlowLayout()); p2.setLayout(new FlowLayout());
p1.add(text); p1.add(text);
this.add(p1, BorderLayout.NORTH); this.add(p1, BorderLayout.NORTH);
p2.setLayout(new GridLayout(5, 4)); // 添加按钮
JButton button[] = new JButton[20]; p2.setLayout(new GridLayout(5, 4));
button[0] = new JButton("C"); // 清空 JButton[] button = new JButton[20];
button[1] = new JButton("CE"); // 清除之前输入的一个数据 button[0] = new JButton("C");
button[2] = new JButton("%"); // 取余 button[1] = new JButton("CE");
button[3] = new JButton("÷"); // 除法 button[2] = new JButton("%");
button[3] = new JButton("÷");
button[4] = new JButton("7"); button[4] = new JButton("7");
button[5] = new JButton("8"); button[5] = new JButton("8");
button[6] = new JButton("9"); button[6] = new JButton("9");
button[7] = new JButton("x"); // 乘号 button[7] = new JButton("*");
button[8] = new JButton("4"); button[8] = new JButton("4");
button[9] = new JButton("5"); button[9] = new JButton("5");
button[10] = new JButton("6"); button[10] = new JButton("6");
button[11] = new JButton("-"); // 减号 button[11] = new JButton("-");
button[12] = new JButton("1"); button[12] = new JButton("1");
button[13] = new JButton("2"); button[13] = new JButton("2");
button[14] = new JButton("3"); button[14] = new JButton("3");
button[15] = new JButton("+"); // 加号 button[15] = new JButton("+");
button[16] = new JButton(" "); // 空格 button[16] = new JButton(" ");
button[17] = new JButton("0"); button[17] = new JButton("0");
button[18] = new JButton("."); // 小数点 button[18] = new JButton(".");
button[19] = new JButton("="); // 等于 button[19] = new JButton("=");
for (int i = 0; i < button.length; i++) // 将组件加入容器
p2.add(button[i]); Arrays.stream(button).forEach(p2::add);
p2.add(button[19]); this.add(p2, BorderLayout.CENTER);
add(p2, BorderLayout.CENTER);
for (int i = 0; i < button.length; i++) // 为每一个事件(按钮)添加监视器 for (JButton jButton : button) {
button[i].addActionListener(this); jButton.addActionListener(this);
}
this.setVisible(true); this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 点击X号可以关闭程序 this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
} }
public void actionPerformed(ActionEvent e) // 事件处理
{
String lab = e.getActionCommand(); // 得到当前的按钮字符，后面进行匹配
if (Character.isDigit(lab.charAt(0)) || lab.equals(".")) { // 处理按钮 0~9 和小数点 public void actionPerformed(ActionEvent e) {
sBuilder.append(lab); // 利用StringBuilder类的对象调用方法，将数据存起来 String lab = e.getActionCommand();
text.setText(sBuilder.toString()); // 显示之前所有输入的数据
} else if (lab.equals("CE")) { // 处理"CE"按钮事件 即清除当前的输入的数据 if (Character.isDigit(lab.charAt(0)) || lab.equals(".")) {
sBuilder.deleteCharAt(sBuilder.length() - 1); // StringBuilder的实例化对象调用方法下标减1即可 sBuilder.append(lab);
text.setText(sBuilder.toString());
} else if (lab.equals("CE")) {
sBuilder.deleteCharAt(sBuilder.length() - 1);
text.setText(sBuilder.toString()); text.setText(sBuilder.toString());
} else if (lab.equals("C")) { // 处理"C"按钮事件 即清除之前的输入所有的数据 } else if (lab.equals("C")) {
sBuilder.setLength(0); // 重新创建即可清除之前的输入所有的数据 sBuilder.setLength(0);
text.setText(""); text.setText("");
} else if (lab.equals("+") || lab.equals("-") || lab.equals("x") || lab.equals("÷") || lab.equals("%")) { // 处理运算符按钮事件 } else if (lab.equals("+") || lab.equals("-") || lab.equals("*") || lab.equals("÷") || lab.equals("%")) {
if (sBuilder.length() > 0) { if (sBuilder.length() > 0) {
a = Double.parseDouble(sBuilder.toString()); // 将前面的输入的数 作为第一个操作数a a = Double.parseDouble(sBuilder.toString());
sBuilder.setLength(0); // 将数组清空来存储第二个操作数 b sBuilder.setLength(0);
lastOperator = lab; lastOperator = lab;
text.setText("" + a + " " + lastOperator + " "); text.setText(MessageFormat.format("{0} {1} ", a, lastOperator));
} }
} else if (lab.equals("=")) { // 处理"="按钮事件 } else if (lab.equals("=")) {
if (lastOperator != null && !lastOperator.isEmpty() && sBuilder.length() > 0) { if (lastOperator != null && !lastOperator.isEmpty() && sBuilder.length() > 0) {
b = Double.parseDouble(sBuilder.toString()); // 一遇到"=",我们就能得到第二个操作数b b = Double.parseDouble(sBuilder.toString());
calculate(); // 调用计算方法 calculate();
} }
} else if (lab.equals(" ")) { // 处理空格按钮事件
// 空格按键无功能
} }
} }
@ -96,7 +102,7 @@ class JS extends JFrame implements ActionListener {
case "-": case "-":
sum = a - b; sum = a - b;
break; break;
case "x": case "*":
sum = a * b; sum = a * b;
break; break;
case "÷": case "÷":
@ -113,8 +119,6 @@ class JS extends JFrame implements ActionListener {
} }
sum = a % b; sum = a % b;
break; break;
default:
return;
} }
text.setText(sum + ""); text.setText(sum + "");
sBuilder.setLength(0); sBuilder.setLength(0);

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