Swing KeyAdapter類
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。這個類是方便類創建監聽器對象。
類聲明
以下是聲明 java.awt.event.KeyAdapter類:
public abstract class KeyAdapter extends Object implements KeyListener
類構造函數
S.N. | 構造函數 & 描述 |
---|---|
1 | KeyAdapter() |
類方法
S.N. | 方法 & 描述 |
---|---|
1 |
void keyPressed(KeyEvent e) Invoked when a key has been pressed. |
2 |
void keyReleased(KeyEvent e) Invoked when a key has been released. |
3 |
void keyTyped(KeyEvent e) Invoked when a key has been typed. |
方法繼承
這個類從以下類繼承的方法:
-
java.lang.Object
KeyAdapter 例子
選擇使用任何編輯器創建以下java程序在 D:/ > SWING > com > yiibai > gui >
SwingAdapterDemo.javapackage com.yiibai.gui; import java.awt.*; import java.awt.event.*; public class SwingAdapterDemo { private JFrame mainFrame; private JLabel headerLabel; private JLabel statusLabel; private JPanel controlPanel; public SwingAdapterDemo(){ prepareGUI(); } public static void main(String[] args){ SwingAdapterDemo swingAdapterDemo = new SwingAdapterDemo(); swingAdapterDemo.showKeyAdapterDemo(); } private void prepareGUI(){ mainFrame = new JFrame("Java SWING Examples"); 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("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。到 D:/ > SWING 然後輸出以下命令。
D:SWING>javac comyiibaiguiSwingAdapterDemo.java
如果冇有錯誤出現,這意味著編譯成功。使用下麵的命令來運行程序。
D:SWING>java com.yiibai.gui.SwingAdapterDemo
驗證下麵的輸出