Question

我有一个可编辑的JComboBox。我只需要按照情况发射事件

用户在键入时按Enter键（这可以实现添加键事件监听器）或
用户从列表中选择项目

在以下代码event fires while user typing in the editor as well中，如何在用户输入时避免事件触发？

comboForward.addItemListener(new ItemListener() {
        public void itemStateChanged(ItemEvent e) {
            if (e.getStateChange() == ItemEvent.SELECTED) {
               new Thread() {
                    @Override
                   public void run() {
                      // code after the event.
                    }
                }.start();
            }
        }
    });

Answer 1

我认为这适合你。试试吧。

JFrame frame = new JFrame("Welcome!!");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JComboBox cmb = new JComboBox();
cmb.setEditable(true);
cmb.getEditor().getEditorComponent().addKeyListener(new KeyAdapter() {

    @Override
    public void keyReleased(KeyEvent event) {
        if (event.getKeyChar() == KeyEvent.VK_ENTER) {
            if (((JTextComponent) ((JComboBox) ((Component) event
                    .getSource()).getParent()).getEditor()
                    .getEditorComponent()).getText().isEmpty())
                System.out.println("please dont make me blank");
        }
    }
});
frame.add(cmb);

frame.setLocationRelativeTo(null);
frame.setSize(300, 50);
frame.setVisible(true);

请参阅此处：https://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html

如何在JcomboBox中输入或更改所选项目后才触发事件

1 个答案: