我想要计算JTextArea的行号包括包装文本。我从Here Thread
获得了很好的示例代码但我尝试使用Dynamic JTextArea进行修改。但是行号的计算出错了。
以下是我修改的代码：
package fandi.demo;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;
import javax.swing.JTextArea;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class JTextAreaCountModified extends javax.swing.JFrame {
public JTextAreaCountModified() {
initComponents();
setLocationRelativeTo(null);
txtResult.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void insertUpdate(DocumentEvent e) {
if(txtResult.getText().length() > 0) {
lblCountLine.setText(String.valueOf(countLines(txtResult)));
} else {
lblCountLine.setText("0");
}
}
@Override
public void removeUpdate(DocumentEvent e) {
if(txtResult.getText().length() > 0) {
lblCountLine.setText(String.valueOf(countLines(txtResult)));
}else {
lblCountLine.setText("0");
}
}
@Override
public void changedUpdate(DocumentEvent e) {
if(txtResult.getText().length() > 0) {
lblCountLine.setText(String.valueOf(countLines(txtResult)));
}else {
lblCountLine.setText("0");
}
}
});
}
// COUNTING LINE GOES HERE...
public static int countLines(JTextArea textArea) {
AttributedString text = new AttributedString(textArea.getText());
FontRenderContext frc = textArea.getFontMetrics(textArea.getFont()).getFontRenderContext();
AttributedCharacterIterator charIt = text.getIterator();
LineBreakMeasurer lineMeasurer = new LineBreakMeasurer(charIt, frc);
float formatWidth = (float) textArea.getSize().width;
lineMeasurer.setPosition(charIt.getBeginIndex());
int noLines = 0;
while (lineMeasurer.getPosition() < charIt.getEndIndex()) {
lineMeasurer.nextLayout(formatWidth);
noLines++;
}
int lineEnter = textArea.getLineCount();
int countLine = noLines + lineEnter;
return countLine-1;
}
// END OF COUNTING METHOD
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
txtResult = new javax.swing.JTextArea();
jLabel3 = new javax.swing.JLabel();
lblCountLine = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("JTextArea Line Counting include Wrap");
setResizable(false);
jLabel1.setText("Enter paragraph");
jLabel2.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
jLabel2.setForeground(new java.awt.Color(255, 0, 0));
jLabel2.setText("20 line limit.");
txtResult.setColumns(20);
txtResult.setLineWrap(true);
txtResult.setRows(5);
txtResult.setWrapStyleWord(true);
jScrollPane1.setViewportView(txtResult);
jLabel3.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
jLabel3.setText("Information : ");
lblCountLine.setText("...");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(lblCountLine)
.addGap(0, 0, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 458, Short.MAX_VALUE)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jLabel2)
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(jLabel2))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 290, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(lblCountLine))
.addContainerGap(13, Short.MAX_VALUE))
);
pack();
}// </editor-fold>//GEN-END:initComponents
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(JTextAreaCountModified.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(JTextAreaCountModified.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(JTextAreaCountModified.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(JTextAreaCountModified.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new JTextAreaCountModified().setVisible(true);
}
});
}
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JLabel lblCountLine;
private javax.swing.JTextArea txtResult;
// End of variables declaration//GEN-END:variables
}
请帮助，谢谢：）
答案 0 :(得分：4)
请参阅Text Utilities中的getWrappedLines()方法。
答案 1 :(得分：2)
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.text.BadLocationException;
import javax.swing.text.Element;
public class ResizeJTextArea {
private JFrame frame = new JFrame();
private JScrollPane scrollPane = new JScrollPane();
private JTextArea textArea = new JTextArea(15, 15);
private JButton button = new JButton("change");
private Font newFont = new Font("Courier", Font.PLAIN, 10);
public ResizeJTextArea() {
textArea.setText("This is just a line of text, "
+ "This is just a line of text, This is just a line of text, "
+ "This is just a line of text,\nThis is just a line of text,"
+ "This is just a line of text, This is just a line of text,"
+ "\nThis is just a line of text,This is just a line of text, "
+ "This is just a line of text,\nThis is just a line of text,"
+ "This is just a line of text, This is just a line of text,"
+ "\nThis is just a line of text, This is just a line of text,"
+ "\nThis is just a line of text,");
textArea.setLineWrap(true);
textArea.setWrapStyleWord(true);
textArea.setFont(newFont);
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
textArea.setFont(textArea.getFont().deriveFont(20f));
frame.pack();
}
});
scrollPane.setViewportView(textArea);
frame.add(scrollPane);
frame.add(button, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
Element paragraph = textArea.getDocument().getDefaultRootElement();
int contentCount = paragraph.getElementCount();
for (int i = 0; i < contentCount; i++) {
Element e = paragraph.getElement(i);
int rangeStart = e.getStartOffset();
int rangeEnd = e.getEndOffset();
String line;
try {
line = textArea.getText(rangeStart, rangeEnd - rangeStart);
System.out.println(line);
} catch (BadLocationException ex) {
Logger.getLogger(ResizeJTextArea.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ResizeJTextArea fs = new ResizeJTextArea();
}
});
}
}
答案 2 :(得分：1)
最好的是textarea.getLineCount（）;
所以我认为这是最好的
int countLine = this.getLineCount（）;