swing实现计算器
代码如下
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Vector;
public class Calculator {
String str1 = "0"; // 运算数1 初值一定为0 为了程序的安全
String str2 = "0"; // 运算数2
String signal = "+"; // 运算符
String result = "";// 结果
// 状态开关
int k1 = 1;// 开关1 用于选择输入方向 将要写入str2或 str2
int k2 = 1;// 开关2 符号键 次数 k2>1说明进行的是2+3-9+8 这样的多符号运算
int k3 = 1;// 开关3 str1 是否可以被清0 ==1时可以 !=1时不能被清0
int k4 = 1;// 开关4 str2 同上
int k5 = 1;// 开关5 控制小数点可否被录入 ==1时可以 !=1 输入的小数点被丢掉
JButton store; // 寄存器 记录 是否连续按下符号键
@SuppressWarnings("rawtypes")
Vector vt = new Vector(20, 10);
JFrame frame = new JFrame("计算器");
JTextField result_TextField = new JTextField(result, 20);// 20列
JButton clear_Button = new JButton("清除");
JButton button0 = new JButton("0");
JButton button1 = new JButton("1");
JButton button2 = new JButton("2");
JButton button3 = new JButton("3");
JButton button4 = new JButton("4");
JButton button5 = new JButton("5");
JButton button6 = new JButton("6");
JButton button7 = new JButton("7");
JButton button8 = new JButton("8");
JButton button9 = new JButton("9");
JButton button_Dian = new JButton(".");
JButton button_jia = new JButton("+");
JButton button_jian = new JButton("-");
JButton button_cheng = new JButton("*");
JButton button_chu = new JButton("/");
JButton button_dy = new JButton("=");
Calculator() {
button0.setMnemonic(KeyEvent.VK_0);// 等效键
// 其它 等效键 略,
result_TextField.setHorizontalAlignment(JTextField.RIGHT);// 文本框 右对齐
JPanel pan = new JPanel();
pan.setLayout(new GridLayout(4, 4, 5, 5));// 四行四列 边距为5像素
pan.add(button7);
pan.add(button8);
pan.add(button9);
pan.add(button_chu);
pan.add(button4);
pan.add(button5);
pan.add(button6);
pan.add(button_cheng);
pan.add(button1);
pan.add(button2);
pan.add(button3);
pan.add(button_jian);
pan.add(button0);
pan.add(button_Dian);
pan.add(button_dy);
pan.add(button_jia);
pan.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));// pan对象的边距
JPanel pan2 = new JPanel();
pan2.setLayout(new BorderLayout());
pan2.add(result_TextField, BorderLayout.WEST);
pan2.add(clear_Button, BorderLayout.EAST);
frame.setLocation(300, 200); // 主窗口 出现在位置
frame.setResizable(false); // 不能调大小
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(pan2, BorderLayout.NORTH);
frame.getContentPane().add(pan, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
// 事件处理 程 序
// 数 字 键
class Listener implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
String ss = ((JButton) e.getSource()).getText();
store = (JButton) e.getSource();
vt.add(store);
if (k1 == 1) {
if (k3 == 1) {
str1 = "";
k5 = 1;// 还原开关k5状态
}
str1 = str1 + ss;
k3 = k3 + 1;
result_TextField.setText(str1);// 显示
} else if (k1 == 2) {
if (k4 == 1) {
str2 = "";
k5 = 1; // 还原开关k5状态
}
str2 = str2 + ss;
k4 = k4 + 1;
result_TextField.setText(str2);
}
}
}
// 符 号
class Listener_signal implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
String ss2 = ((JButton) e.getSource()).getText();
store = (JButton) e.getSource();
vt.add(store);
if (k2 == 1) {
k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写
k5 = 1;
signal = ss2;
k2 = k2 + 1;// 按符号键的次数
} else {
int a = vt.size();
JButton c = (JButton) vt.get(a - 2);
if (!(c.getText().equals("+"))
&& !(c.getText().equals("-"))
&& !(c.getText().equals("*"))
&& !(c.getText().equals("/")))
{
cal();
str1 = result;
k1 = 2;// 开关 k1 为1时,向数1写 为2时，向数2写
k5 = 1;
k4 = 1;
signal = ss2;
}
k2 = k2 + 1;
}
}
}
// 清除
class Listener_clear implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
store = (JButton) e.getSource();
vt.add(store);
k5 = 1;
k2 = 1;
k1 = 1;
k3 = 1;
k4 = 1;
str1 = "0";
str2 = "0";
signal = "";
result = "";
result_TextField.setText(result);
vt.clear();
}
}
// 等 于
class Listener_dy implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
store = (JButton) e.getSource();
vt.add(store);
cal();
k1 = 1; // 还原开关k1状态
// str1=result;
k2 = 1;
k3 = 1;// 还原开关k3状态
k4 = 1; // 还原开关k4状态
str1 = result; // 为7+5=12 +5=17 这种计算做准备
}
}
// 小数点
class Listener_xiaos implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
store = (JButton) e.getSource();
vt.add(store);
if (k5 == 1) {
String ss2 = ((JButton) e.getSource()).getText();
if (k1 == 1) {
if (k3 == 1) {
str1 = "";
k5 = 1; // 还原开关k5状态
}
str1 = str1 + ss2;
k3 = k3 + 1;
result_TextField.setText(str1);// 显示
} else if (k1 == 2) {
if (k4 == 1) {
str2 = "";
k5 = 1; // 还原开关k5状态
}
str2 = str2 + ss2;
k4 = k4 + 1;
result_TextField.setText(str2);
}
}
k5 = k5 + 1;
}
}
// 注册 监听器
Listener_dy jt_dy = new Listener_dy();
Listener jt = new Listener();// 临听数字键
Listener_signal jt_signal = new Listener_signal();// 临 听符 号键
Listener_clear jt_c = new Listener_clear(); // 清除键
Listener_xiaos jt_xs = new Listener_xiaos();// 小数点 键
button7.addActionListener(jt);
button8.addActionListener(jt);
button9.addActionListener(jt);
button_chu.addActionListener(jt_signal);
button4.addActionListener(jt);
button5.addActionListener(jt);
button6.addActionListener(jt);
button_cheng.addActionListener(jt_signal);
button1.addActionListener(jt);
button2.addActionListener(jt);
button3.addActionListener(jt);
button_jian.addActionListener(jt_signal);
button0.addActionListener(jt);
button_Dian.addActionListener(jt_xs);
button_dy.addActionListener(jt_dy);
button_jia.addActionListener(jt_signal);
clear_Button.addActionListener(jt_c);
// 关闭事件处理程序
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}
// 计 算
public void cal() {
double a2;// 运算数1
double b2;// 运算数2
String c = signal;// 运算符
double result2 = 0;// 结果
if (c.equals("")) {
result_TextField.setText("请输入运算符");
} else {
if (str1.equals(".")) // 字符串 "." 转换成double型数据时 会出错 所以手工转
str1 = "0.0";
if (str2.equals("."))
str2 = "0.0";
a2 = Double.valueOf(str1).doubleValue();
b2 = Double.valueOf(str2).doubleValue();
if (c.equals("+")) {
result2 = a2 + b2;
}
if (c.equals("-")) {
result2 = a2 - b2;
}
if (c.equals("*")) {
result2 = a2 * b2;
}
if (c.equals("/")) {
if (b2 == 0) {
result2 = 0;
} else {
result2 = a2 / b2;
}
}
result = ((new Double(result2)).toString());
result_TextField.setText(result);
}
}
@SuppressWarnings("unused")
public static void main(String[] args) {
// 界面风格，可以去除
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}
Calculator cal = new Calculator();
}
}
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