2、Java设计一个计算器,其中要使用按钮、文本框、布局管理和标签等构件,能实现加、减、乘、除运算。
时间: 2023-06-13 18:04:08 浏览: 72
这里是一个简单的 Java 计算器的代码示例:
```java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame implements ActionListener {
private JTextField textField;
private JButton button1, button2, button3, button4;
private JButton button5, button6, button7, button8;
private JButton button9, button0, buttonPlus, buttonMinus;
private JButton buttonMultiply, buttonDivide, buttonEqual, buttonClear;
private JLabel label;
private JPanel panel;
private double firstNumber = 0;
private String operator = "";
public Calculator() {
super("Calculator");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(false);
textField = new JTextField(10);
button1 = new JButton("1");
button2 = new JButton("2");
button3 = new JButton("3");
button4 = new JButton("4");
button5 = new JButton("5");
button6 = new JButton("6");
button7 = new JButton("7");
button8 = new JButton("8");
button9 = new JButton("9");
button0 = new JButton("0");
buttonPlus = new JButton("+");
buttonMinus = new JButton("-");
buttonMultiply = new JButton("*");
buttonDivide = new JButton("/");
buttonEqual = new JButton("=");
buttonClear = new JButton("C");
label = new JLabel("", JLabel.CENTER);
panel = new JPanel(new GridLayout(4, 4));
panel.add(button1);
panel.add(button2);
panel.add(button3);
panel.add(buttonPlus);
panel.add(button4);
panel.add(button5);
panel.add(button6);
panel.add(buttonMinus);
panel.add(button7);
panel.add(button8);
panel.add(button9);
panel.add(buttonMultiply);
panel.add(button0);
panel.add(buttonEqual);
panel.add(buttonClear);
panel.add(buttonDivide);
add(textField, BorderLayout.NORTH);
add(panel, BorderLayout.CENTER);
add(label, BorderLayout.SOUTH);
button1.addActionListener(this);
button2.addActionListener(this);
button3.addActionListener(this);
button4.addActionListener(this);
button5.addActionListener(this);
button6.addActionListener(this);
button7.addActionListener(this);
button8.addActionListener(this);
button9.addActionListener(this);
button0.addActionListener(this);
buttonPlus.addActionListener(this);
buttonMinus.addActionListener(this);
buttonMultiply.addActionListener(this);
buttonDivide.addActionListener(this);
buttonEqual.addActionListener(this);
buttonClear.addActionListener(this);
pack();
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
String buttonText = e.getActionCommand();
if (buttonText.equals("C")) {
textField.setText("");
label.setText("");
firstNumber = 0;
operator = "";
} else if (buttonText.equals("+")) {
firstNumber = Double.parseDouble(textField.getText());
operator = "+";
textField.setText("");
} else if (buttonText.equals("-")) {
firstNumber = Double.parseDouble(textField.getText());
operator = "-";
textField.setText("");
} else if (buttonText.equals("*")) {
firstNumber = Double.parseDouble(textField.getText());
operator = "*";
textField.setText("");
} else if (buttonText.equals("/")) {
firstNumber = Double.parseDouble(textField.getText());
operator = "/";
textField.setText("");
} else if (buttonText.equals("=")) {
double secondNumber = Double.parseDouble(textField.getText());
double result = 0;
if (operator.equals("+")) {
result = firstNumber + secondNumber;
} else if (operator.equals("-")) {
result = firstNumber - secondNumber;
} else if (operator.equals("*")) {
result = firstNumber * secondNumber;
} else if (operator.equals("/")) {
result = firstNumber / secondNumber;
}
textField.setText(Double.toString(result));
label.setText(firstNumber + " " + operator + " " + secondNumber + " = " + result);
firstNumber = 0;
operator = "";
} else {
textField.setText(textField.getText() + buttonText);
}
}
public static void main(String[] args) {
new Calculator();
}
}
```
这个计算器使用了 JFrame 和各种 Swing 组件来实现。你可以在按钮上点击,然后在文本框中输入数字来进行计算。计算器可以实现加、减、乘、除运算,并且有一个清除按钮,可以清除当前的计算结果。