停止在Java中输入JTextField后如何启动函数
问题内容:
停止在JTextField中键入后如何启动函数。并非每个关键版本。如果两个键的释放时间差大于1秒,则它将运行此功能。否则,请等待1秒钟。
问题答案:
使用Swing Timer
和a DocumentListener
每次Document
更新时,重置Timer
看看如何使用Swing计时器和侦听文档中的更改以了解更多详细信息
作为一个简单的例子…
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
JTextField field = new JTextField(20);
JLabel label = new JLabel("Waiting");
DeferredDocumentListener listener = new DeferredDocumentListener(1000, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// Execute your required functionality here...
label.setText(label.getText() + ".");
}
}, true);
field.getDocument().addDocumentListener(listener);
field.addFocusListener(new FocusListener() {
@Override
public void focusGained(FocusEvent e) {
listener.start();
}
@Override
public void focusLost(FocusEvent e) {
listener.stop();
}
});
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(field, gbc);
add(label, gbc);
}
}
public class DeferredDocumentListener implements DocumentListener {
private final Timer timer;
public DeferredDocumentListener(int timeOut, ActionListener listener, boolean repeats) {
timer = new Timer(timeOut, listener);
timer.setRepeats(repeats);
}
public void start() {
timer.start();
}
public void stop() {
timer.stop();
}
@Override
public void insertUpdate(DocumentEvent e) {
timer.restart();
}
@Override
public void removeUpdate(DocumentEvent e) {
timer.restart();
}
@Override
public void changedUpdate(DocumentEvent e) {
timer.restart();
}
}
}