Java - JTextField - 当用户按下“空格键”时调用函数。 [英] Java - JTextField - Call function when user press "space bar"

问题描述

我做了一些搜索，当用户按下空格键键时我没有找到如何调用函数，我有这样的代码：

I made some searches and I didn't find how to call a function when the user press the key "space bar", I have this code:

edtCodigos.addKeyListener(new KeyAdapter() {
    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_SPACE){
            callFunction();
        }
    }
)};

注意：我想避开空格，该键只用于调用函数

Note: I want to avoid the "space", the key will be used just to call the function

任何想法我该怎么做或代码样本都将不胜感激;）

Any ideas how can I do it or code samples will be appreciated ;)

推荐答案

用户习惯于输入空格键来完成收银员付款等操作。

"The users are used to type "space bar" to finish an operation like payment in a cashier."

就个人而言，我只会使用 ActionListener ，以便 Enter 键触发事件。它看起来更自然。

Personally, I would just use an ActionListener so that the Enter key triggers the event. It just seems more natural.

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

public class TestTextField {

    public static void main(String[] args) {
        final JTextField field = new JTextField(15);
        field.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                System.out.println("Enter Pressed: " + field.getText());
            }
        });
        JOptionPane.showMessageDialog(null, field);
    }
}

如果你想使用 Space ，您可以使用密钥绑定绑定字段的密钥

If you want to use Space, you can bind the key the field using Key Bindings

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

public class TestTextField {

    public static void main(String[] args) {
        final JTextField field = new JTextField(15);
        InputMap imap = field.getInputMap(JComponent.WHEN_FOCUSED);
        imap.put(KeyStroke.getKeyStroke("SPACE"), "spaceAction");
        ActionMap amap = field.getActionMap();
        amap.put("spaceAction", new AbstractAction(){
            public void actionPerformed(ActionEvent e) {
                System.out.println("Space Pressed: " + field.getText());
            }
        });
        JOptionPane.showMessageDialog(null, field);
    }
}

你甚至可以使用 DocumentListener ，用于侦听文本字段的基础文档中的更改，以及检查输入的最后一个字符是一个空格（但这似乎有点多 - 只是一些信息，你可以学习文本组件的工作： - ）

You could even go as far as using a DocumentListener to listen for changes in the underlying document of the text field, and check the last character entered was a space (but this seems like a bit much - Just some info for you to learn the workings for text components :-)

选择你的味道。我喜欢第一个。

Pick your flavor. I like the first.

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