下面给出的代码对一个JTextField进行实时验证。在向txt1输入一些值时，启用保存按钮并删除值会重置保存按钮以禁用。我使用Netbeans作为IDE。
我的Swing应用程序有很少的JTextFields。我想要做的是，在检查多个JTextFields的有效性后启用“保存”按钮。如果任何文本字段为空，则必须禁用btnSave。
有人可以协助我扩展此程序以验证多个JTextField吗？
public NewJFrame() {
initComponents();
btnSave.setEnabled(false);
txt1.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent e) {
}
@Override
public void removeUpdate(DocumentEvent e) {
validate(e);
}
@Override
public void insertUpdate(DocumentEvent e) {
validate(e);
}
public void validate(DocumentEvent e) {
String currText = "";
try {
Document doc = (Document) e.getDocument();
currText = doc.getText(0, doc.getLength());
} catch (BadLocationException e1) {
e1.printStackTrace();
}
if (currText.isEmpty()) {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField1 = false;
validFormatterLimit();
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField1 = true;
validFormatterLimit();
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
txt2.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent e) {
}
@Override
public void removeUpdate(DocumentEvent e) {
validate(e);
}
@Override
public void insertUpdate(DocumentEvent e) {
validate(e);
}
public void validate(DocumentEvent e) {
String currText = "";
try {
Document doc = (Document) e.getDocument();
currText = doc.getText(0, doc.getLength());
} catch (BadLocationException e1) {
e1.printStackTrace();
}
if (currText.isEmpty()) {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField2 = false;
validFormatterLimit();
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField2 = true;
validFormatterLimit();
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
}
public void validFormatterLimit() {
if (isValidFromTextField1 == true && isValidFromTextField2 == true) {
btnSave.setEnabled(true);
} else {
btnSave.setEnabled(false);
}
}
答案 0 :(得分：2)
必须拆分验证
应从每个JComponents
包含所需步骤的非常简单的示例
通过Swing Timer延迟（3,5秒）
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.font.TextAttribute;
import java.math.*;
import java.text.*;
import java.util.Map;
import java.util.Vector;
import javax.swing.*;
import javax.swing.JFormattedTextField.AbstractFormatter;
import javax.swing.JFormattedTextField.AbstractFormatterFactory;
import javax.swing.event.*;
import javax.swing.text.InternationalFormatter;
public class FormatterLimit {
private JFrame frame = new JFrame("AbstractTextField Test");
private Map attributes = (new Font("Serif", Font.BOLD, 16)).getAttributes();
private JFormattedTextField textField1 = new JFormattedTextField(new Float(710.01));
private JFormattedTextField textField2 = new JFormattedTextField(new Float(150.01));
private Vector<Boolean> comboBoxItems = new Vector<Boolean>();
private JComboBox box = new JComboBox(comboBoxItems);
private JButton btn = new JButton("Validations !!!");
private Boolean isValidFromTextField1 = true;
private Boolean isValidFromTextField2 = true;
private Boolean isValidFromBox = true;
private javax.swing.Timer timer = null;
public FormatterLimit() {
attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);
textField1.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
formatter.setMinimum(0.0);
formatter.setMaximum(1000.00);
return formatter;
}
});
textField1.getDocument().addDocumentListener(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) textField1.getValue()).doubleValue());
if (t1a1 < 500) {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField1 = false;
validFormatterLimit();
textField1.setFont(new Font(attributes));
textField1.setForeground(Color.red);
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField1 = true;
validFormatterLimit();
textField1.setFont(new Font("Serif", Font.BOLD, 16));
textField1.setForeground(Color.black);
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
textField2.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
//formatter.setMinimum(0.0);
//formatter.setMaximum(1000.00);
return formatter;
}
});
textField2.getDocument().addDocumentListener(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) textField2.getValue()).doubleValue());
if (t1a1 > 1000) {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField2 = false;
validFormatterLimit();
textField2.setFont(new Font(attributes));
textField2.setForeground(Color.red);
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
isValidFromTextField2 = true;
validFormatterLimit();
textField2.setFont(new Font("Serif", Font.BOLD, 16));
textField2.setForeground(Color.black);
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
comboBoxItems.add(Boolean.TRUE);
comboBoxItems.add(Boolean.FALSE);
box = new JComboBox(comboBoxItems);
box.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED) {
if (e.getSource() == box) {
if (box.getSelectedItem() == (Boolean) true) {
isValidFromBox = true;
validFormatterLimit();
} else {
isValidFromBox = false;
validFormatterLimit();
}
}
}
}
});
frame.setLayout(new GridLayout(5, 0, 5, 5));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(textField1);
frame.add(textField2);
frame.add(box, BorderLayout.SOUTH);
frame.add(new JLabel());
frame.add(btn);
frame.setVisible(true);
frame.pack();
start();
}
private void start() {
timer = new javax.swing.Timer(3500, updateCol());
timer.setRepeats(false);
timer.start();
}
public Action updateCol() {
return new AbstractAction("text load action") {
private static final long serialVersionUID = 1L;
@Override
public void actionPerformed(ActionEvent e) {
textField1.setValue(300);
textField2.setValue(8000);
if (box.getSelectedItem() == (Boolean) false) {
box.setSelectedItem((Boolean) true);
} else {
box.setSelectedItem((Boolean) false);
}
}
};
}
public void validFormatterLimit(/*Boolean isValidFromTextField1,
* Boolean isValidFromTextField2 , Boolean isValidFromBox*/) {
if (isValidFromTextField1) {
if (isValidFromTextField2) {
if (isValidFromBox) {
btn.setEnabled(true);
} else {
btn.setEnabled(false);
}
} else {
btn.setEnabled(false);
}
} else {
btn.setEnabled(false);
}
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
FormatterLimit comboBoxModel = new FormatterLimit();
}
});
}
}