JList右键单击显示菜单(使用，拖放，取消) [英] JList Right-click shows menu (Use, drop, cancel)

问题描述

我一直在互联网上寻找这个答案.我有一个简单的JList，其中包含项目.右键单击时，我要弹出一个菜单，上面写着使用，删除，取消"或类似的内容.但是，我很困惑.

I've been scouring the internet for this answer. I have a simple JList with items inside it. When I right-click, I want a menu to pop-up that says "Use, drop, cancel" or something of that nature. HOWEVER, I'm stumped.

下面的代码将生成一个简单的JList，其中包含一些项.我尝试在代码中添加右键单击，但是它不起作用.帮助吗?

The code below will produce a simple JList with a few items inside. I tried adding a right-click in the code but it doesn't work. Help?

这是我到目前为止所拥有的:

Here is what I have so far:

import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseAdapter;
import javax.swing.*;



public class inv extends JApplet implements MouseListener {

    JList listbox;



     public void init()
     {


    String  listData[] = { "Item 1","Item 2","Item 3","Item 4" };
listbox = new JList( listData );

     listbox.addMouseListener( new MouseAdapter()
     {
        public void mousePressed(MouseEvent e)
        {
            if ( SwingUtilities.isRightMouseButton(e) )
            {
                listbox.setSelectedIndex(getRow(e.getPoint()));
            }
        }
     });

    listbox.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);


        add(listbox);
                    listbox.setVisible(true);

            listbox.setFocusable(false);

     }



     private int getRow(Point point)
     {
        return listbox.locationToIndex(point);
}

      public void mousePressed(MouseEvent e) {
      }

      public void mouseReleased(MouseEvent e) {
      }

      public void mouseEntered(MouseEvent e) {
      }

      public void mouseExited(MouseEvent e) {
      }

      public void mouseClicked(MouseEvent e) {
      }


     public void stop()
     {
     }

     public void paint(Graphics g)
     {
     }

}

推荐答案

我不知道您的意思.这是看起来像您指定的那样工作的代码，但是除了删除任何数量的冗余或错误的语句之外，它几乎是您发布的内容.

I do not know what you mean. Here is code that seems to work like you specify, but apart from taking out any number of redundant or buggy statements, it is pretty much what you posted.

/*
<applet code='inv' width='200' height='200'>
</applet>
*/
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import javax.swing.*;

public class inv extends JApplet { //implements MouseListener {

    JList listbox;

     public void init()
     {


    String  listData[] = { "Item 1","Item 2","Item 3","Item 4" };
listbox = new JList( listData );

     listbox.addMouseListener( new MouseAdapter()
     {
        public void mousePressed(MouseEvent e)
        {
            System.out.println(e);
            if ( SwingUtilities.isRightMouseButton(e) )
            {
                System.out.println("Row: " + getRow(e.getPoint()));
                listbox.setSelectedIndex(getRow(e.getPoint()));
            }
        }
     });

    listbox.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        add(listbox);
                    // unnecessary
                    //listbox.setVisible(true);

            listbox.setFocusable(false);
     }



     private int getRow(Point point)
     {
        return listbox.locationToIndex(point);
}

/** Why implement MouseListener, while adding a MouseAdapter?
Do you have ANY idea what your doing?

      public void mousePressed(MouseEvent e) {
      }

      public void mouseReleased(MouseEvent e) {
      }

      public void mouseEntered(MouseEvent e) {
      }

      public void mouseExited(MouseEvent e) {
      }

      public void mouseClicked(MouseEvent e) {
      }
*/

    /** What is this nonsense supposed to achieve?
    Don't override empty methods with empty implementations!
     public void stop()
     {
     }
     */

    /** What is this nonsense supposed to achieve?
     public void paint(Graphics g)
     {
     }
     */
}

输出

java.awt.event.MouseEvent[MOUSE_PRESSED,(31,22),absolute(39,72),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1] on javax.swing.JList[,0,0,200x200,alignmentX=0.0,alignmentY=0.0,border=,flags=50331944,maximumSize=,minimumSize=,preferredSize=,fixedCellHeight=-1,fixedCellWidth=-1,horizontalScrollIncrement=-1,selectionBackground=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],selectionForeground=sun.swing.PrintColorUIResource[r=51,g=51,b=51],visibleRowCount=8,layoutOrientation=0]
Row: 1
java.awt.event.MouseEvent[MOUSE_PRESSED,(29,39),absolute(37,89),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1] on javax.swing.JList[,0,0,200x200,alignmentX=0.0,alignmentY=0.0,border=,flags=50331944,maximumSize=,minimumSize=,preferredSize=,fixedCellHeight=-1,fixedCellWidth=-1,horizontalScrollIncrement=-1,selectionBackground=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],selectionForeground=sun.swing.PrintColorUIResource[r=51,g=51,b=51],visibleRowCount=8,layoutOrientation=0]
Row: 2
java.awt.event.MouseEvent[MOUSE_PRESSED,(36,65),absolute(468,192),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1] on javax.swing.JList[,0,0,200x200,alignmentX=0.0,alignmentY=0.0,border=,flags=50331944,maximumSize=,minimumSize=,preferredSize=,fixedCellHeight=-1,fixedCellWidth=-1,horizontalScrollIncrement=-1,selectionBackground=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],selectionForeground=sun.swing.PrintColorUIResource[r=51,g=51,b=51],visibleRowCount=8,layoutOrientation=0]
Row: 3
java.awt.event.MouseEvent[MOUSE_PRESSED,(45,11),absolute(477,138),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1] on javax.swing.JList[,0,0,200x200,alignmentX=0.0,alignmentY=0.0,border=,flags=50331944,maximumSize=,minimumSize=,preferredSize=,fixedCellHeight=-1,fixedCellWidth=-1,horizontalScrollIncrement=-1,selectionBackground=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],selectionForeground=sun.swing.PrintColorUIResource[r=51,g=51,b=51],visibleRowCount=8,layoutOrientation=0]
Row: 0

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