FocusAdapter類接收鍵盤焦點事件是一個抽象類(適配器)。這個類的所有方法都是空的。這個類是方便的類創(chuàng)建監(jiān)聽器對象。
以下是聲明 java.awt.event.FocusAdapter類:
public abstract class FocusAdapter extends Object implements FocusListener
S.N. | 構造函數(shù) & 描述 |
---|---|
1 | FocusAdapter() |
S.N. | 方法 & 描述 |
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1 |
void focusGained(FocusEvent e) Invoked when a component gains the keyboard focus. |
2 |
focusLost(FocusEvent e) Invoked when a component loses the keyboard focus. |
這個類從以下類繼承的方法:
java.lang.Object
選擇使用任何編輯器創(chuàng)建以下java程序在 D:/ > SWING > com > yiibai > gui >
SwingAdapterDemo.javapackage com.yiibai.gui; import java.awt.*; import java.awt.event.*; import javax.swing.*; 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.showFocusAdapterDemo(); } 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 showFocusAdapterDemo(){ headerLabel.setText("Listener in action: FocusAdapter"); JButton okButton = new JButton("OK"); JButton cancelButton = new JButton("Cancel"); okButton.addFocusListener(new FocusAdapter(){ public void focusGained(FocusEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " gained focus. "); } }); cancelButton.addFocusListener(new FocusAdapter(){ public void focusLost(FocusEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass上一篇:Swing JFrame類和實例下一篇:Swing事件處理