java - 可编辑 JCombobox mouseclicked 事件不起作用

Question

我现在的处境很尴尬，所以我来这里寻求一些专家的建议。我有一个可编辑的 JComboBox。我已经实现了 actionPerformed 事件，效果很好。但我已经实现了 mouseListener ，但它不起作用。

component = jcbItemType.getEditor().getEditorComponent();
component.addMouseListener(new java.awt.event.MouseListener() {
    public void mouseClicked(java.awt.event.MouseEvent evt) {
        jcbItemTypeMouseClicked(evt);
    }
    public void mousePressed(java.awt.event.MouseEvent evt) {
        jcbItemTypeMousePressed(evt);
    }
    public void mouseReleased(java.awt.event.MouseEvent evt) {
        jcbItemTypeMouseReleased(evt);
    }
    public void mouseExited(java.awt.event.MouseEvent evt) {
        jcbItemTypeMouseReleased(evt);
    }
    public void mouseEntered(java.awt.event.MouseEvent evt) {
        jcbItemTypeMouseReleased(evt);
    }
});

我还尝试了以下代码:

Component[] comps = jcbItemType.getComponents();
for(int i = 0; i < comps.length; i++)
{    
    comps[i].addMouseListener(new java.awt.event.MouseAdapter() {
        public void mouseClicked(java.awt.event.MouseEvent evt) {
            jcbItemTypeMouseClicked(evt);
        }
        public void mousePressed(java.awt.event.MouseEvent evt) {
            jcbItemTypeMousePressed(evt);
        }
        public void mouseReleased(java.awt.event.MouseEvent evt) {
            jcbItemTypeMouseReleased(evt);
        }
        public void mouseExited(java.awt.event.MouseEvent evt) {
            jcbItemTypeMouseReleased(evt);
        }
        public void mouseEntered(java.awt.event.MouseEvent evt) {
            jcbItemTypeMouseReleased(evt);
        }
    });
}

我知道 JComboBox 是一个复合元素，因此直接鼠标处理事件将不起作用。但我已经使用了单个组件的 mouseListener 但它也不起作用。

有人可以询问 stateChanged 事件，但我想在完全选择项目后加载一些信息，而不是在我只输入项目的 2/3 个字符时加载一些信息。在 stateChanged 事件中，如果仅在 2/3 个字符后显示项目信息，则负载很重，因为我针对每个项目的信息的权重很大。

那么，如何获取通过鼠标单击选择项目时的事件呢？

Answer 1

以下链接解决了我的问题。

http://engin-tekin.blogspot.com/2009/10/hrefhttpkfd.html

链接中的代码片段如下:

import java.lang.reflect.InvocationTargetException;  
import java.awt.event.MouseAdapter;  
import java.lang.reflect.Field;  
import javax.swing.*;  
import javax.swing.plaf.basic.BasicComboPopup;  
import javax.swing.plaf.basic.BasicComboBoxUI;  
import java.awt.event.MouseEvent;  

/** 
 * User: destiny 
 * Date: Oct 19, 2009 
 * Time: 9:18:34 PM 
 */  
public class JComboPopupMouseListenerDemo {  

    private static void addPopupMouseListener(JComboBox box) {  
        try {  
                  Field popupInBasicComboBoxUI = BasicComboBoxUI.class.getDeclaredField("popup");  
                popupInBasicComboBoxUI.setAccessible(true);  
                BasicComboPopup popup = (BasicComboPopup) popupInBasicComboBoxUI.get(box.getUI());  

                Field scrollerInBasicComboPopup = BasicComboPopup.class.getDeclaredField("scroller");  
                scrollerInBasicComboPopup.setAccessible(true);  
                JScrollPane scroller = (JScrollPane) scrollerInBasicComboPopup.get(popup);  

                scroller.getViewport().getView().addMouseListener(this);  
//                ((JViewport) ((JScrollPane) ((BasicComboPopup) popupInBasicComboBoxUI.get(box.getUI())).getComponents()[0]).getComponents()[0]).getComponents()[0].addMouseListener(this);  
        }  
        catch (NoSuchFieldException e) {  
            e.printStackTrace();  
        }  
        catch (IllegalAccessException e) {  
            e.printStackTrace();  
        }  
    }  

    private static MouseAdapter listener() {  
        return new MouseAdapter(){  
            public void mouseClicked(MouseEvent mouseEvent) {  
                System.out.println("mouseClicked");  
            }  

            public void mousePressed(MouseEvent mouseEvent) {  
                System.out.println("mousePressed");  
            }  

            public void mouseReleased(MouseEvent mouseEvent) {  
                System.out.println("mouseReleased");  
            }  

            public void mouseEntered(MouseEvent mouseEvent) {  
                System.out.println("mouseEntered");  
            }  

            public void mouseExited(MouseEvent mouseEvent) {  
                System.out.println("mouseExited");  
            }  
        };  
    }  

    public static void main(String[] args) throws InvocationTargetException, InterruptedException {  
        JComboBox box = new JComboBox(new String[]{"val 1","val 2","val ......","val 4","val 5","val 6"});  
        box.setEditable(true);  
        addPopupMouseListener(box);  

        JFrame frame = new JFrame();  
        frame.add(box);  
        frame.pack();  
        frame.setVisible(true);  
    }  
}