I want to get the value from my JList by using an ActionListener. When user selects an index and the selected index updated, i want to get the updated value.
How can i do it without pressing a button? I want to add ActionListener to my JList.
How can i do it without pressing a button? I want to add ActionListener to my JList.
No, you really don't want to "add an ActionListener" to a JList since that is not allowed, since JList has no addActionListener(...)
method, but you do need to add a listener , and which one is easily found by looking up the JList tutorial or the JList API . There you'll find your best option, a ListSelectionListener .
Useful resources:
For example:
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
@SuppressWarnings("serial")
public class ListListenerDemo extends JPanel {
private static final String[] LIST_DATA = { "Sunday", "Monday", "Tuesday", "Wednesday",
"Thursday", "Friday", "Saturday" };
private JList<String> list = new JList<>(LIST_DATA);
public ListListenerDemo() {
list.setVisibleRowCount(4);
// add the ListSelectionListener to our JList
list.addListSelectionListener(new MyListListener());
JScrollPane scrollPane = new JScrollPane(list);
add(scrollPane);
}
// here's our ListSelectionListener
private class MyListListener implements ListSelectionListener {
@Override
public void valueChanged(ListSelectionEvent e) {
if (!e.getValueIsAdjusting()) {
JList<String> lst = (JList<String>) e.getSource();
String selection = lst.getSelectedValue();
if (selection != null) {
JOptionPane.showMessageDialog(list, selection, "Selected Item",
JOptionPane.INFORMATION_MESSAGE);
}
}
}
}
private static void createAndShowGui() {
ListListenerDemo mainPanel = new ListListenerDemo();
JFrame frame = new JFrame("ListListenerDemo");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
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