隐藏/显示JTextField

我有一个JTextField，它在开始时必须隐藏，并且必须在特定情况下显示。
这是我的代码：

package StudentNotes; import java.awt.BorderLayout; public class EditCourse extends JDialog { private JTextField textField; /** * Create the dialog. */ public EditCourse(JDialog mainFrame, final StudApp studAppObj) { super(mainFrame, ModalityType.APPLICATION_MODAL); setPreferredSize(new Dimension(330, 200)); setTitle("Edit course"); setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); setAlwaysOnTop(true); ArrayList listCourses = studAppObj.getCorsi(); listCourses.toArray(); String[] listData = { "one", "two", "three", "four", "five", "six", "seven" }; final JList list = new JList(listData); list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); list.getSelectionModel().addListSelectionListener(new ListSelectionListener() { @Override public void valueChanged(ListSelectionEvent e) { if (e.getValueIsAdjusting() == true) { textField.setVisible(true); // it does not show (why?) } } }); JScrollPane scrollPane = new JScrollPane(list); scrollPane.setSize(new Dimension(118, 40)); textField = new JTextField(); textField.setVisible(false); // it is invisible (OK) textField.setColumns(10); GroupLayout groupLayout = new GroupLayout(getContentPane()); groupLayout.setHorizontalGroup( groupLayout.createParallelGroup(Alignment.LEADING) .addGroup(groupLayout.createSequentialGroup() .addGap(108) .addGroup(groupLayout.createParallelGroup(Alignment.LEADING) .addComponent(textField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE) .addComponent(scrollPane, GroupLayout.PREFERRED_SIZE, 108, GroupLayout.PREFERRED_SIZE)) .addContainerGap(108, Short.MAX_VALUE)) ); groupLayout.setVerticalGroup( groupLayout.createParallelGroup(Alignment.LEADING) .addGroup(groupLayout.createSequentialGroup() .addGap(21) .addComponent(scrollPane, GroupLayout.PREFERRED_SIZE, 64, GroupLayout.PREFERRED_SIZE) .addGap(18) .addComponent(textField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE) .addContainerGap(49, Short.MAX_VALUE)) ); getContentPane().setLayout(groupLayout); pack(); setLocationRelativeTo(null); setResizable(false); setVisible(true); } } 

这个想法是：
当用户单击要在JList上编辑的值时，必须显示JTextField

Answer 1

textField.setVisible(true); 如果您尝试显示/隐藏可见容器的组件，则需要调用包含JTextField的容器的revalidate()和repaint()方法。

所以只需在代码中添加下一行，所有内容都可以正常工作：

  EditCourse.this.revalidate(); EditCourse.this.repaint(); 

Answer 2

在将文本字段设置为可见之后，您是否尝试过使用textField.revalidate()然后再使用textField.revalidate() ？