我应该为每个类似的动作或通用动作单独使用ActionListener吗？ [英] Should I use separate ActionListener for each similar action or generic one?

问题描述

我使用java创建一个使用按钮的键盘，当用户点击从A到Z标签的按钮时，它会将JTextField文本设置为A或按任何按钮。

I'm creating a keyboard using buttons with java, when a user clicks on a button labelled from A to Z it will set a JTextField text to A or whatever button they pressed.

我有一个单独的类为每个按钮，所以A它的 public class listenser1实现ActionListener ，B它的 public class listenser2实现ActionListener 这是一个很好的方法吗？

I have a seperate class for each button so for A its public class listenser1 implements ActionListener, B its public class listenser2 implements ActionListener is this a good way of doing it?

我也试图做一个类，并使用if和if else语句购买使用

Also I tried to do do it under one class and used if and if else statements buy using

        if(a.getText().equals("A"))
        {
           input1.setText(input.getText() + "A");       
        }
        .
        .
        .

这不起作用，它打印出ABCDEFGHIJKLMNOPQRSTUVWXYZ而不是一个字母。

And this doesn't work, it prints out ABCDEFGHIJKLMNOPQRSTUVWXYZ instead of just the one letter.

推荐答案

不，这不是最有效的方式。写得太久了。相反，请尝试：

No, that is not the most efficient way. That takes way too long to write. Instead, try this:

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

public class Example extends JFrame implements ActionListener {
    private final String[] letters = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"};
    private JButton[] buttons = new JButton[26];
    private JTextArea text = new JTextArea();

    public Example() {
        super("Example");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        for (int i = 0; i < letters.length; i++) {
            buttons[i] = new JButton(letters[i]);
            buttons[i].addActionListener(this);
            add(buttons[i]);
        }
        add(text);
        pack();
        setVisible(true);
    }

    public void actionPerformed(ActionEvent event) {
        text.append(event.getActionCommand());
    }

    public static void main(String[] args) {
        Example ex = new Example();
    }
}

这篇关于我应该为每个类似的动作或通用动作单独使用ActionListener吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！