我一直在网上搜索这个答案。我有一个简单的 JList，其中包含项目。当我右键单击时，我希望弹出一个菜单，上面写着“使用、删除、取消”或类似的内容。但是，我很难过。

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

这是我目前所拥有的:

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)
     {
     }

}

最佳答案

我不明白你的意思。这里的代码看起来像您指定的那样工作，但除了删除任何数量的冗余或错误语句之外，它几乎就是您发布的内容。

/*
<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

Tool completed successfully

关于java - JList 右键显示菜单(使用、删除、取消)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4854185/