java - JComboBox 在下拉列表中导航选择项目

Question

这是我的第一个问题，我对我的英语感到非常抱歉。我不想在 JComboBox 的下拉列表中导航显示“JComboBox 的主字段”中的所选项目(抱歉，不知道如何调用它，请参阅图像)。

这是我在列表中导航时发生的情况:

但我想要这样的东西:

当我按 Enter 或单击项目时，它会出现在主字段中。

这是我的代码:

import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.awt.*;

public class ComboTest {

JFrame frame;
JPanel panel;
String[] choices = new String[]{
        "Java",
        "Python",
        "C++",
        "PHP",
        "Perl"
};
JComboBox<String> comboBox = new JComboBox<>(choices);
JTextComponent textComponent;

public static void main(String[] args){
    new ComboTest();
}

public ComboTest() {

    frame = new JFrame();
    panel = new JPanel();
    textComponent = (JTextComponent) comboBox.getEditor().getEditorComponent();

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300, 150);
    frame.setResizable(false);

    panel.setLayout(new FlowLayout());

    comboBox.setEditable(true);
    comboBox.setSelectedItem(null);

    panel.add(comboBox);
    frame.add(panel);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
}
}

Answer 1

尝试这个代码块

   comboBox.addPopupMenuListener(new PopupMenuListener() {

        @Override
        public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
            //when Popupmenu is visible, remove the combobox editor text 
            comboBox.getEditor().setItem(null);

        }

        @Override
        public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
        }

        @Override
        public void popupMenuCanceled(PopupMenuEvent e) {
        }
    });