突出显示JTextArea中的一个特定行/行
我试图突出显示JTextArea一个特定行，但我不知道如何去做。 我需要获取特定的行然后突出显示它。 我已经阅读了其他post，但我仍然不明白如何将它们整合在一起来解决我的问题…帮助将非常感激。
试试这个代码示例，并询问是否有不清楚的地方：
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.text.*; public class TextHighlight { private JTextArea tarea; private JComboBox cbox; private JTextField lineField; private String[] colourNames = {"RED", "ORANGE", "CYAN"}; private Highlighter.HighlightPainter painter; private void createAndDisplayGUI() { final JFrame frame = new JFrame("Text HIGHLIGHT"); frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); JPanel contentPane = new JPanel(); contentPane.setBorder(BorderFactory.createTitledBorder( BorderFactory.createEmptyBorder(5, 5, 5, 5), "Highlighter JTextArea")); tarea = new JTextArea(10, 10); JScrollPane scrollPane = new JScrollPane(tarea); contentPane.add(scrollPane); JButton button = new JButton("HIGHLIGHT TEXT"); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { int selection = JOptionPane.showConfirmDialog( frame, getOptionPanel(), "Highlighting Options : ", JOptionPane.OK_CANCEL_OPTION , JOptionPane.PLAIN_MESSAGE); if (selection == JOptionPane.OK_OPTION) { System.out.println("OK Selected"); int lineNumber = Integer.parseInt(lineField.getText().trim()); try { int startIndex = tarea.getLineStartOffset(lineNumber); int endIndex = tarea.getLineEndOffset(lineNumber); String colour = (String) cbox.getSelectedItem(); if (colour == colourNames[0]) { System.out.println("RED Colour"); painter = new DefaultHighlighter.DefaultHighlightPainter(Color.RED); tarea.getHighlighter().addHighlight(startIndex, endIndex, painter); } else if (colour == colourNames[1]) { System.out.println("ORANGE Colour"); painter = new DefaultHighlighter.DefaultHighlightPainter(Color.ORANGE); tarea.getHighlighter().addHighlight(startIndex, endIndex, painter); } else if (colour == colourNames[2]) { System.out.println("CYAN Colour"); painter = new DefaultHighlighter.DefaultHighlightPainter(Color.CYAN); tarea.getHighlighter().addHighlight(startIndex, endIndex, painter); } } catch(BadLocationException ble) { ble.printStackTrace(); } } else if (selection == JOptionPane.CANCEL_OPTION) { System.out.println("CANCEL Selected"); } else if (selection == JOptionPane.CLOSED_OPTION) { System.out.println("JOptionPane closed deliberately."); } } }); frame.add(contentPane, BorderLayout.CENTER); frame.add(button, BorderLayout.PAGE_END); frame.pack(); frame.setLocationByPlatform(true); frame.setVisible(true); } private JPanel getOptionPanel() { JPanel panel = new JPanel(); panel.setLayout(new GridLayout(0, 2, 5, 5)); JLabel lineNumberLabel = new JLabel("Enter Line Number : "); lineField = new JTextField(10); JLabel colourLabel = new JLabel("Select One Colour : "); cbox = new JComboBox(colourNames); panel.add(lineNumberLabel); panel.add(lineField); panel.add(colourLabel); panel.add(cbox); return panel; } public static void main(String... args) { SwingUtilities.invokeLater(new Runnable() { public void run() { new TextHighlight().createAndDisplayGUI(); } }); } }
这是它的输出：
如果您无法选择TextArea到TextField，则单击按钮会导致JTextArea失去焦点，因此不会显示其选择。 按钮单击事件使用btnImport.transferFocusBackward(); 解决问题。