KeyAdapter類

介紹

KeyAdapter類是一個抽象類（適配器）用於接收鍵盤事件。這個類的所有方法都是空的。這個類是方便的類創建偵聽器對象。

類的聲明

以下是聲明的java.awt.event.KeyAdapter類：

public abstract class KeyAdapter extends Object implements KeyListener

類的構造函數

S.N.

構造函數＆說明

KeyAdapter()

類方法

S.N.

方法＆說明

void keyPressed(KeyEvent e)
Invoked when a key has been pressed.

void keyReleased(KeyEvent e)
Invoked when a key has been released.

void keyTyped(KeyEvent e)
Invoked when a key has been typed.

繼承的方法

這個類繼承的方法從以下類：

java.lang.Object

KeyAdapter實例

選擇使用任何編輯器創建以下java程序 D:/ > AWT > com > yiibai > gui >

AwtAdapterDemo

package com.yiibai.gui; import java.awt.*; import java.awt.event.*; public class AwtAdapterDemo { private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; public AwtAdapterDemo(){ prepareGUI(); } public static void main(String[] args){ AwtAdapterDemo awtAdapterDemo = new AwtAdapterDemo(); awtAdapterDemo.showKeyAdapterDemo(); } private void prepareGUI(){ mainFrame = new Frame("Java AWT Examples"); mainFrame.setSize(400,400); mainFrame.setLayout(new GridLayout(3, 1)); mainFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent windowEvent){ System.exit(0); } }); headerLabel = new Label(); headerLabel.setAlignment(Label.CENTER); statusLabel = new Label(); statusLabel.setAlignment(Label.CENTER); statusLabel.setSize(350,100); controlPanel = new Panel(); 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 TextField textField = new TextField(10); textField.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if(e.getKeyCode() == KeyEvent.VK_ENTER){ statusLabel.setText("Entered text: " + textField.getText()); } } }); Button okButton = new Button("OK"); okButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { statusLabel.setText("Entered text: " + textField.getText()); } }); controlPanel.add(textField); controlPanel.add(okButton); mainFrame.setVisible(true); } }

編譯程序，使用命令提示符。進入到D:/> AWT，然後鍵入以下命令。

D:AWT>javac comyiibaiguiAwtAdapterDemo.java

如果沒有錯誤出現，這意味着編譯成功。使用下面的命令來運行程序。

D:AWT>java com.yiibai.gui.AwtAdapterDemo

驗證下面的輸出

AWT