我有 JTextField 来显示文件名。如果文件无效，我想删除文本。怎么能做到这一点？我尝试了 html，但没有运气。
【问题讨论】：
标签： java swing jtextfield
简单可行，
1) 使用HTML syntax
2）通过工具TextAttribute（我喜欢这种方式）
import java.awt.*;
import java.awt.event.*;
import java.awt.font.TextAttribute;
import java.math.RoundingMode;
import java.text.NumberFormat;
import java.util.Map;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.event.*;
public class TextAttributeSTRIKETHROUGH {
private JFrame frame = new JFrame();
private JPanel pnl = new JPanel();
private JLabel focusLabel = new JLabel(" focusLost Handle ");
private JFormattedTextField formTextField;
private JLabel docLabel = new JLabel(" document Handle ");
private JFormattedTextField formTextField1;
private NumberFormat formTextFieldFormat;
private double amount = 10000.00;
private Map attributes;
@SuppressWarnings("unchecked")
public TextAttributeSTRIKETHROUGH() {
formTextFieldFormat = NumberFormat.getNumberInstance();
formTextFieldFormat.setMinimumFractionDigits(2);
formTextFieldFormat.setMaximumFractionDigits(2);
formTextFieldFormat.setRoundingMode(RoundingMode.HALF_UP);
focusLabel.setFont(new Font("Serif", Font.BOLD, 14));
focusLabel.setForeground(Color.blue);
focusLabel.setPreferredSize(new Dimension(120, 27));
formTextField = new JFormattedTextField(formTextFieldFormat);
formTextField.setValue(amount);
formTextField.setFont(new Font("Serif", Font.BOLD, 22));
formTextField.setForeground(Color.black);
formTextField.setBackground(Color.yellow);
formTextField.setPreferredSize(new Dimension(120, 27));
formTextField.setHorizontalAlignment(SwingConstants.RIGHT);
formTextField.addFocusListener(new FocusListener() {
@Override
public void focusGained(FocusEvent e) {
formTextField.requestFocus();
formTextField.setText(formTextField.getText());
formTextField.selectAll();
}
public void focusLost(FocusEvent e) {
//Runnable doRun = new Runnable() {
//@Override
//public void run() {
double t1a1 = (((Number) formTextField.getValue()).doubleValue());
if (t1a1 < 1000) {
formTextField.setValue(amount);
}
//}
// };
//SwingUtilities.invokeLater(doRun);
}
});
docLabel.setFont(new Font("Serif", Font.BOLD, 14));
docLabel.setForeground(Color.blue);
docLabel.setPreferredSize(new Dimension(120, 27));
formTextField1 = new JFormattedTextField(formTextFieldFormat);
formTextField1.setValue(amount);
formTextField1.setFont(new Font("Serif", Font.BOLD, 22));
formTextField1.setForeground(Color.black);
formTextField1.setBackground(Color.yellow);
formTextField1.setPreferredSize(new Dimension(120, 27));
formTextField1.setHorizontalAlignment(SwingConstants.RIGHT);
formTextField1.addFocusListener(new FocusListener() {
@Override
public void focusGained(FocusEvent e) {
formTextField1.requestFocus();
formTextField1.setText(formTextField1.getText());
formTextField1.selectAll();
}
@Override
public void focusLost(FocusEvent e) {
}
});
formTextField1.getDocument().addDocumentListener(docListener);
attributes = (new Font("Serif", Font.BOLD, 24)).getAttributes();
attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);
pnl = new JPanel();
pnl.setBorder(new EmptyBorder(2, 2, 2, 2));
pnl.setLayout(new GridLayout(2, 2));
pnl.add(focusLabel);
pnl.add(formTextField);
pnl.add(docLabel);
pnl.add(formTextField1);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(pnl, BorderLayout.CENTER);
frame.setLocation(200, 200);
frame.pack();
frame.setVisible(true);
formTextFieldFocus1();
}
//
private DocumentListener docListener = new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void insertUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void removeUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
private void printIt(DocumentEvent documentEvent) {
DocumentEvent.EventType type = documentEvent.getType();
double t1a1 = (((Number) formTextField1.getValue()).doubleValue());
if (t1a1 < 1000) {
Runnable doRun = new Runnable() {
@Override
public void run() {
formTextField1.setFont(new Font(attributes));
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
formTextField1.setFont(new Font("Serif", Font.BOLD, 22));
}
};
SwingUtilities.invokeLater(doRun);
}
}
};
private void formTextFieldFocus1() {
Runnable doRun = new Runnable() {
@Override
public void run() {
formTextField1.grabFocus();
formTextField1.requestFocus();
formTextField1.setText(formTextField1.getText());
formTextField1.selectAll();
}
};
SwingUtilities.invokeLater(doRun);
}
private void formTextFieldFocus() {
Runnable doRun = new Runnable() {
@Override
public void run() {
formTextField.grabFocus();
formTextField.requestFocus();
formTextField.setText(formTextField.getText());
formTextField.selectAll();
formTextFieldFocus1();
}
};
SwingUtilities.invokeLater(doRun);
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
TextAttributeSTRIKETHROUGH fl = new TextAttributeSTRIKETHROUGH();
}
});
}
}
【讨论】：
我敢肯定，除了设置字体之外，您不能在 JTextField 中设置文本样式。我认为您要么必须创建自己的支持样式的子类，要么创建 JTextPane 并将其设置为像 JTextField 一样。
这里有一些很好的文档：http://download.oracle.com/javase/tutorial/uiswing/components/editorpane.html
【讨论】：