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我最近在学习Java编程
2023-06-15 16:40:32 深夜i     --     --
Java 计算器 Swing库

我最近在学习Java编程，今天我想分享一个简单的Java计算器的代码。在我编写这个计算器时，我主要利用了Java中的Swing库来帮助构建GUI界面。下面是我的代码示例：



import javax.swing.*;


import java.awt.*;


import java.awt.event.*;


public class SimpleCalculator implements ActionListener {


  JTextField textField;


  JButton[] buttons = new JButton[16];


  String[] buttonLabels = {"1", "2", "3", "+", "4", "5", "6", "-", "7", "8", "9", "*", ".", "0", "C", "/"};


  String firstNumber = "";


  String secondNumber = "";


  String operator = "";


  Double result = 0.0;


  public SimpleCalculator() {


    JFrame frame = new JFrame("简易计算器");


    frame.setLayout(new BorderLayout());


    frame.setSize(250, 300);


    frame.setLocationRelativeTo(null);


    textField = new JTextField();


    textField.setEditable(false);


    frame.add(textField, BorderLayout.NORTH);


    JPanel buttonPanel = new JPanel(new GridLayout(4, 4));


    for (int i = 0; i < 16; i++) {


      buttons[i] = new JButton(buttonLabels[i]);


      buttons[i].addActionListener(this);


      buttonPanel.add(buttons[i]);


    }


    frame.add(buttonPanel, BorderLayout.CENTER);


    frame.setVisible(true);


    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


  }


  public static void main(String[] args) {


    SimpleCalculator calculator = new SimpleCalculator();


  }


  public void actionPerformed(ActionEvent e) {


    String command = e.getActionCommand();


    switch (command) {


      case "C":


        firstNumber = "";


        secondNumber = "";


        operator = "";


        result = 0.0;


        textField.setText("");


        break;


      case "+":


      case "-":


      case "*":


      case "/":


        operator = command;


        firstNumber = textField.getText();


        textField.setText("");


        break;


      case "=":


        secondNumber = textField.getText();


        Double num1 = Double.parseDouble(firstNumber);


        Double num2 = Double.parseDouble(secondNumber);


        switch (operator) {


          case "+":


            result = num1 + num2;


            break;


          case "-":


            result = num1 - num2;


            break;


          case "*":


            result = num1 * num2;


            break;


          case "/":


            result = num1 / num2;


            break;


          default:


            break;


        }


        textField.setText(result.toString());


        break;


      default:


        textField.setText(textField.getText() + command);


        break;


    }


  }


}

通过这个代码，我学会了如何创建一个简单的Java计算器。我还学到了如何使用Swing库来构建GUI界面，如何使用ActionListener来捕获用户的动作并根据用户的输入来执行一系列操作。这个计算器可以帮助我更好地理解Java编程的基础知识，我可以用它来练习其他编程技能。

  
  

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