处理action仅在用户确认选择时才在JComboBox上执行

Question

当我在不可编辑的JComboBox上注册ActionListener时,每当用户使用箭头键或上下文搜索(键入项目名称的第一个字母)更改所选项时,它就会触发actionPerformed().

我在这里找到了类似的问题: 如何在使用键盘滚动弹出列表时使JComboBox所选项目不被更改.但该解决方案不包括上下文搜索选项.当我输入内容时,它会触发actionPerformed().

如何确定用户何时使用回车键或鼠标点击确认所选项目？

Answer 1

更好的是实现ItemListener(激发两次SELECTED和DESELECTED),而不是ActionListener和KeyBindings,也许这里有一个简单的例子

import java.awt.*;
import javax.swing.*;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;

public class PopupTest {

    public static void main(String[] args) {
        final JComboBox c = new JComboBox();
        c.addPopupMenuListener(new PopupMenuListener() {

            @Override
            public void popupMenuCanceled(PopupMenuEvent e) {
                System.out.println(e.getSource());
            }

            @Override
            public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
                System.out.println(e.getSource());
            }

            @Override
            public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
                System.out.println(e.getSource());
            }
        });
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        f.getContentPane().setLayout(new FlowLayout());
        f.getContentPane().add(c);
        f.pack();
        f.setVisible(true);
    }

    private PopupTest() {
    }
}