s22.htm

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            <p>&nbsp;</p>
            <p align="center"><b>例22-5 单行文本域和缺省按钮</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import javax.swing.text.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JFrame {<br>
              private JTextField field = new JTextField(10);<br>
              private JButton b = new JButton(&quot;Default Button&quot;);<br>
              private JCheckBox cb = new JCheckBox(<br>
              &quot;Text field fires action event&quot;);<br>
              public Test() {<br>
              Container contentPane = getContentPane();</p>
            <p> SwingUtilities.getRootPane(this).setDefaultButton(b);<br>
              cb.setSelected(true);</p>
            <p> contentPane.setLayout(new FlowLayout(<br>
              FlowLayout.CENTER,10,20));<br>
              contentPane.add(field);<br>
              contentPane.add(b);<br>
              contentPane.add(cb);</p>
            <p> b.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              JOptionPane.showMessageDialog(Test.this,<br>
              &quot;Button fired action event&quot;);<br>
              }<br>
              });<br>
              field.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              JOptionPane.showMessageDialog(Test.this,<br>
              &quot;Textfield fired action event&quot;);<br>
              }<br>
              });<br>
              cb.addActionListener(new ActionListener() {<br>
              private Keymap km;<br>
              private KeyStroke ks;<br>
              private Action action;</p>
            <p> public void actionPerformed(ActionEvent e) {<br>
              if(cb.isSelected()) {<br>
              km.addActionForKeyStroke(ks, action);<br>
              }<br>
              else {<br>
              if(ks == null) {<br>
              km = field.getKeymap();<br>
              ks = KeyStroke.getKeyStroke(<br>
              KeyEvent.VK_ENTER, 0);<br>
              action = km.getAction(ks);<br>
              }<br>
              km.removeKeyStrokeBinding(ks);<br>
              }<br>
              }<br>
              });<br>
              }<br>
              public static void main(String args[]) {<br>
              GJApp.launch(new Test(), <br>
              &quot;Default Buttons&quot;,300,300,350,200);<br>
              }<br>
              }<br>
              class GJApp extends WindowAdapter {<br>
              static private JPanel statusArea = new JPanel();<br>
              static private JLabel status = new JLabel(&quot; &quot;);<br>
              static private ResourceBundle resources;</p>
            <p> public static void launch(final JFrame f, String title,<br>
              final int x, final int y, <br>
              final int w, int h) {<br>
              launch(f,title,x,y,w,h,null); <br>
              }<br>
              public static void launch(final JFrame f, String title,<br>
              final int x, final int y, <br>
              final int w, int h,<br>
              String propertiesFilename) {<br>
              f.setTitle(title);<br>
              f.setBounds(x,y,w,h);<br>
              f.setVisible(true);</p>
            <p> statusArea.setBorder(BorderFactory.createEtchedBorder());<br>
              statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));<br>
              statusArea.add(status);<br>
              status.setHorizontalAlignment(JLabel.LEFT);</p>
            <p> f.setDefaultCloseOperation(<br>
              WindowConstants.DISPOSE_ON_CLOSE);</p>
            <p> if(propertiesFilename != null) {<br>
              resources = ResourceBundle.getBundle(<br>
              propertiesFilename, Locale.getDefault());<br>
              }</p>
            <p> f.addWindowListener(new WindowAdapter() {<br>
              public void windowClosed(WindowEvent e) {<br>
              System.exit(0);<br>
              }<br>
              });<br>
              }<br>
              static public JPanel getStatusArea() {<br>
              return statusArea;<br>
              }<br>
              static public void showStatus(String s) {<br>
              status.setText(s);<br>
              }<br>
              static Object getResource(String key) {<br>
              if(resources != null) {<br>
              return resources.getString(key);<br>
              }<br>
              return null;<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 22.1.6 JTextField事件</p>
            <p>&nbsp;</p>
            <p> 22.1.7 JTextField类总结</p>
            <p>&nbsp;</p>
            <p> 22.1.8 AWT兼容</p>
            <p>&nbsp;</p>
            <p> 22.2 JPasswordField</p>
            <p>&nbsp;</p>
            <p align="center"><b>例22-6 使用JPasswordField</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JApplet {<br>
              private String pw = &quot;dol42ce&quot;;<br>
              private JPasswordField passwordField = new JPasswordField(8);</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();<br>
              JPanel panel = new JPanel();</p>
            <p> panel.add(new JLabel(&quot;Password:&quot;));<br>
              panel.add(passwordField);</p>
            <p> passwordField.setEchoChar('?');</p>
            <p> contentPane.add(panel, BorderLayout.CENTER);</p>
            <p> passwordField.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              String password = new String(<br>
              passwordField.getPassword());</p>
            <p> if(pw.equals(password))<br>
              showStatus(&quot;Access Granted&quot;);<br>
              else<br>
              showStatus(&quot;Wrong password - security &quot; +<br>
              &quot;has been called&quot;);<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 22.2.1 JPasswordField组件总结</p>
            <p>&nbsp;</p>
            <p> 22.2.2 JPasswordField属性</p>
            <p>&nbsp;</p>
            <p> 22.2.3 JPasswordField类总结</p>
            <p>&nbsp;</p>
            <p> 22.3 JTextArea</p>
            <p>&nbsp;</p>
            <p align="center"><b>例22-7 指定JTExtArea的换行行为</b></p>
            <hr size="1" noshade>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import javax.swing.*;<br>
            import javax.swing.text.*;<br>
            import java.io.FileReader;
            <p>public class Test extends JApplet {<br>
              private JTextArea textArea = new JTextArea();<br>
              private Container contentPane = getContentPane();</p>
            <p> public void init() {<br>
              readFile(textArea, &quot;text&quot;);<br>
              contentPane.add(new ControlPanel(), BorderLayout.NORTH);<br>
              contentPane.add(new JScrollPane(textArea), <br>
              BorderLayout.CENTER);<br>
              }<br>
              private void readFile(JTextComponent textComponent,String s) {<br>
              try { (new DefaultEditorKit()).read(<br>
              new FileReader(s), textComponent.getDocument(), 0);<br>
              } catch(Exception ex) { ex.printStackTrace(); }<br>
              }<br>
              class ControlPanel extends JPanel { <br>
              JRadioButton radioButtons[] = new JRadioButton[] {<br>
              new JRadioButton(&quot;wrap off&quot;),<br>
              new JRadioButton(&quot;wrap characters&quot;),<br>
              new JRadioButton(&quot;wrap words&quot;),<br>
              };</p>
            <p> public ControlPanel() {<br>
              ButtonGroup group = new ButtonGroup();<br>
              Listener listener = new Listener();</p>
            <p> for(int i=0; i &lt; radioButtons.length; ++i) {<br>
              JRadioButton b = radioButtons[i];</p>
            <p> b.addActionListener(listener);<br>
              group.add(b);<br>
              add(b);</p>
            <p> if(i == 0) <br>
              b.setSelected(true); // &quot;wrap off&quot;<br>
              }<br>
              }<br>
              class Listener implements ActionListener {<br>
              public void actionPerformed(ActionEvent e) {<br>
              String action = e.getActionCommand();</p>
            <p> textArea.setLineWrap(!action.equals(&quot;wrap off&quot;));<br>
              textArea.setWrapStyleWord(<br>
              action.equals(&quot;wrap words&quot;));<br>
              //textArea.repaint();</p>
            <p> showStatus(&quot;rows: &quot; + textArea.getRows() +<br>
              &quot;, columns: &quot; + textArea.getColumns() +<br>
              &quot;, lines: &quot; + textArea.getLineCount());</p>
            <p> }<br>
              };<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 22.3.1 JTextArea组件总结</p>
            <p>&nbsp;</p>
            <p> 22.3.2 JTextArea属性</p>
            <p>&nbsp;</p>
            <p> 22.3.3 JTextArea类总结</p>
            <p>&nbsp;</p>
            <p> 22.3.4 AWT兼容</p>
            <p>&nbsp;</p>
            <p> 22.4 JEditorPane</p>
            <p>&nbsp;</p>
            <p align="center"><b>例22-8 用一个编辑器窗格来显示HTML文件</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JFrame {<br>
              private JEditorPane editorPane = new JEditorPane();</p>
            <p> public Test() {<br>
              Container contentPane = getContentPane();</p>
            <p> String url = &quot;file:&quot; + System.getProperty(&quot;user.dir&quot;) 
              +<br>
              System.getProperty(&quot;file.separator&quot;) +<br>
              &quot;java.util.Hashtable.html&quot;;</p>
            <p> editorPane.setEditable(false);</p>
            <p> try { <br>
              editorPane.setPage(url);<br>
              }<br>
              catch(Exception ex) { ex.printStackTrace(); }</p>
            <p> contentPane.add(new ControlPanel(), BorderLayout.NORTH);<br>
              contentPane.add(new JScrollPane(editorPane), <br>
              BorderLayout.CENTER);<br>
              }<br>
              class ControlPanel extends JPanel {<br>
              private JCheckBox edit = new JCheckBox(&quot;Editable&quot;);</p>
            <p> public ControlPanel() {<br>
              add(edit);<br>
              edit.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              editorPane.setEditable(edit.isSelected());<br>
              }<br>
              });<br>
              }<br>
              }<br>
              public static void main(String args[]) {<br>
              GJApp.launch(new Test(), <br>
              &quot;JEditorPane&quot;,300,300,650,450);<br>
              }<br>
              }<br>
              class GJApp extends WindowAdapter {<br>
              static private JPanel statusArea = new JPanel();<br>
              static private JLabel status = new JLabel(&quot; &quot;);<br>
              static private ResourceBundle resources;</p>
            <p> public static void launch(final JFrame f, String title,<br>
              final int x, final int y, <br>
              final int w, int h) {<br>
              launch(f,title,x,y,w,h,null); <br>
              }<br>
              public static void launch(final JFrame f, String title,<br>
              final int x, final int y, <br>
              final int w, int h,<br>
              String propertiesFilename) {<br>
              f.setTitle(title);<br>
              f.setBounds(x,y,w,h);<br>
              f.setVisible(true);</p>
            <p> statusArea.setBorder(BorderFactory.createEtchedBorder());<br>
              statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));<br>
              statusArea.add(status);<br>
              status.setHorizontalAlignment(JLabel.LEFT);</p>
            <p> f.setDefaultCloseOperation(<br>
              WindowConstants.DISPOSE_ON_CLOSE);</p>
            <p> if(propertiesFilename != null) {<br>
              resources = ResourceBundle.getBundle(<br>
              propertiesFilename, Locale.getDefault());<br>
              }</p>
            <p> f.addWindowListener(new WindowAdapter() {<br>
              public void windowClosed(WindowEvent e) {<br>
              System.exit(0);<br>
              }<br>
              });<br>
              }<br>
              static public JPanel getStatusArea() {<br>
              return statusArea;<br>
              }<br>
              static public void showStatus(String s) {<br>
              status.setText(s);<br>
              }<br>
              static Object getResource(String key) {<br>
              if(resources != null) {<br>
              return resources.getString(key);<br>
              }<br>
              return null;<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 22.4.1 JEditorPane属性</p>
            <p>&nbsp;</p>
            <p> 22.4.2 JEditorPane事件</p>
            <p>&nbsp;</p>
            <p align="center"><b>例22-9 用超链接监听器来装载URL</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import javax.swing.event.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;<br>
            import java.io.IOException;
            <p>public class Test extends JFrame {<br>
              private JEditorPane editorPane = new JEditorPane();</p>
            <p> public Test() {<br>
              Container contentPane = getContentPane();<br>
              String url = &quot;file:&quot; + System.getProperty(&quot;user.dir&quot;) 
              +<br>
              System.getProperty(&quot;file.separator&quot;) +<br>
              &quot;java.util.Hashtable.html&quot;;</p>
            <p> try { <br>
              editorPane.setPage(url);<br>
              }<br>
              catch(IOException ex) { ex.printStackTrace(); }</p>
            <p> contentPane.add(new JScrollPane(editorPane), <br>
              BorderLayout.CENTER);</p>
            <p> editorPane.setEditable(false);</p>
            <p> editorPane.addHyperlinkListener(new HyperlinkListener() {<br>
              public void hyperlinkUpdate(HyperlinkEvent e) {<br>
              try { <br>
              editorPane.setPage(e.getURL());<br>