Swing KeyAdapter類

KeyAdapter類是一個用於接收鍵盤事件的抽象(介面卡)類。此類的所有方法都是空的。此類是用於建立偵聽器物件的便捷類。

類宣告

以下是java.awt.event.KeyAdapter類的宣告 -

public abstract class KeyAdapter
   extends Object
      implements KeyListener

類建構函式

類方法

方法繼承

該類繼承以下類中的方法 -

• java.lang.Object

KeyAdapter範例

使用編輯器建立以下Java程式：KeyAdapterDemo.java

package com.yiibai.swing.listener;

import javax.swing.*;

import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.*;

public class KeyAdapterDemo {
    private JFrame mainFrame;
    private JLabel headerLabel;
    private JLabel statusLabel;
    private JPanel controlPanel;

    public KeyAdapterDemo() {
        prepareGUI();
    }

    public static void main(String[] args) {
        KeyAdapterDemo swingAdapterDemo = new KeyAdapterDemo();
        swingAdapterDemo.showKeyAdapterDemo();
    }

    private void prepareGUI() {
        mainFrame = new JFrame("Java SWING KeyAdapter範例(tw511.com)");
        mainFrame.setSize(400, 400);
        mainFrame.setLayout(new GridLayout(3, 1));

        headerLabel = new JLabel("", JLabel.CENTER);
        statusLabel = new JLabel("", JLabel.CENTER);
        statusLabel.setSize(350, 100);

        mainFrame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent windowEvent) {
                System.exit(0);
            }
        });
        controlPanel = new JPanel();
        controlPanel.setLayout(new FlowLayout());

        mainFrame.add(headerLabel);
        mainFrame.add(controlPanel);
        mainFrame.add(statusLabel);
        mainFrame.setVisible(true);
    }

    private void showKeyAdapterDemo() {
        headerLabel.setText("Listener in action: KeyAdapter");
        final JTextField textField = new JTextField(10);

        textField.addKeyListener(new KeyAdapter() {
            public void keyPressed(KeyEvent e) {
                if (e.getKeyCode() == KeyEvent.VK_ENTER) {
                    statusLabel.setText("Entered text: " + textField.getText());
                }
            }
        });
        JButton okButton = new JButton("確定");
        okButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                statusLabel.setText("Entered text: " + textField.getText());
            }
        });
        controlPanel.add(textField);
        controlPanel.add(okButton);
        mainFrame.setVisible(true);
    }
}

執行上面範例程式碼，得到以下結果：