java - 如何给多个按钮提供不同的命令

Question

我一直在尝试用Javax swing制作一个计算器。我知道如何让一个按钮有一个命令，但我不知道如何在Java中为多个按钮提供更多命令？我想为按钮提供 a0-clear 操作。

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class Calculator extends JFrame {

    private JButton a0;
    private JButton a1;
    private JButton a2;
    private JButton a3;
    private JButton a4;
    private JButton a5;
    private JButton a6;
    private JButton a7;
    private JButton a8;
    private JButton a9;
    private JButton clear;
    private JButton plusminus;
    private JButton plus;
    private JButton minus;
    private JButton multiply;
    private JButton divide;
    private JButton equal;
    private JButton decimal;

    private JLabel resultLabel;

    public Calculator() {
        setLayout(new FlowLayout());

        a0 = new JButton("0");
        add(a0);

        a1 = new JButton("1");
        add(a1);

        a2 = new JButton("2");
        add(a2);

        a3 = new JButton("3");
        add(a3);

        a4 = new JButton("4");
        add(a4);

        a5 = new JButton("5");
        add(a5);

        a6 = new JButton("6");
        add(a6);

        a7 = new JButton("7");
        add(a7);

        a8 = new JButton("8");
        add(a8);

        a9 = new JButton("9");
        add(a9);

        decimal = new JButton(".");
        add(decimal);

        clear = new JButton("C");
        add(clear);

        plusminus = new JButton("+/-");
        add(plusminus);

        plus = new JButton("+");
        add(plus);

        minus = new JButton("-");
        add(minus);

        multiply = new JButton("X");
        add(multiply);

        divide = new JButton("/");
        add(divide);

        equal = new JButton("=");
        add(equal);

        resultLabel = new JLabel("");
        add(resultLabel);

    }

    public class event implements ActionListener {

        public void actionPerformed(ActionEvent event) {

            a0.addActionListener(this);

            a1.addActionListener(this);

            a2.addActionListener(this);

            a3.addActionListener(this);

            a4.addActionListener(this);

            a5.addActionListener(this);

            a6.addActionListener(this);

            a7.addActionListener(this);

            a8.addActionListener(this);

            a9.addActionListener(this);

            clear.addActionListener(this);

            decimal.addActionListener(this);

            plusminus.addActionListener(this);

            plus.addActionListener(this);

            minus.addActionListener(this);

            multiply.addActionListener(this);

            divide.addActionListener(this);

            equal.addActionListener(this);

            if (event.getSource() == a1) {
                resultLabel.setText("0");
            }

        }
    }

    public static void main(String[] args) {
        Calculator gui = new Calculator();
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        gui.setSize(300, 800);
        gui.setVisible(true);
        gui.setTitle("Caclculator");

    }
}

Answer 1

我将向您展示 1 个按钮，对所有其他按钮执行相同的操作，

public class Calculator extends JFrame  implements ActionListener {

    JButton a0 = new JButton("0");
    a0.addActionListener(this);
    add(a0); 

    public void actionPerformed(ActionEvent event) {

        String command = e.getActionCommand();

        switch(command){

            case "0":
                    //do whatever want while button '0' press
                    break;
            case "1":
                    //do whatever want while button '1' press
                    break;
            case "2":
                    //do whatever want while button '2' press
                    break;      


        }

    }
}