Question

我有JList选择的问题。当我单击JList中的任何对象时，它将被选中（这很好）。

但是当我点击所有对象（空白处）下方时，将选择JList中的最后一项。我怎么能把它关掉？单击下面的所有对象（在空白处）后，我不想在JList中选择最后一个对象。

在几条评论之后，我在这里添加代码示例。

import java.awt.Color;
import java.awt.Dimension;

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListSelectionModel;
import javax.swing.UIManager;
import javax.swing.UIManager.LookAndFeelInfo;

public class TestOfJList extends JFrame{

private static JList playList;
private static DefaultListModel<String> modelPlayList;  
private static JPanel mainPanel;
private static MyCellRenderer myRendererForJlist;

private static void createAndShowGUI() {

    JFrame.setDefaultLookAndFeelDecorated(true);
    try {       
        for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    }catch (Exception e){
      e.printStackTrace();
    }

    JFrame frame = new JFrame("JListTest!");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setBounds(700, 250, 300, 400);       
    frame.setResizable(false);    

    mainPanel = new JPanel();

    modelPlayList = new DefaultListModel<String>();

    modelPlayList.addElement("Hello world!");
    modelPlayList.addElement("Hello heaven!");
    modelPlayList.addElement("Hello hell!");


    playList = new JList(modelPlayList);

    playList.setPreferredSize(new Dimension(270,500));
    playList.setVisible(true);
    playList.setBackground(Color.LIGHT_GRAY);       
    playList.setSelectionBackground(Color.YELLOW);      
    playList.setSelectedIndex(0);
    playList.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
    playList.setDragEnabled(true);      
    playList.setDropMode(javax.swing.DropMode.ON_OR_INSERT);
    playList.setFixedCellHeight(20);        

    JScrollPane scrollPane = new JScrollPane(playList);
    scrollPane.setPreferredSize(new Dimension(300,400));

    mainPanel.add(scrollPane);

    myRendererForJlist = new MyCellRenderer();      
    playList.setCellRenderer(myRendererForJlist);

    frame.add(mainPanel);       
    frame.setVisible(true);     
}

public static void main(String[] args) {

    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGUI();
        }
    });
}
}

MCVE 2：

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

public class TestList {
   public static final String[] ITEMS = { "One", "Two", "Three", "Four", "Five" };

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            JList<String> myList = new JList<>(ITEMS);
            myList.setVisibleRowCount(10);
            JScrollPane sPane = new JScrollPane(myList);

            // just to see what listeners are involved
            MouseListener[] mouseListeners = myList.getListeners(MouseListener.class);
            System.out.println(mouseListeners.length);

            MouseMotionListener[] mouseMotionListeners = myList.getListeners(MouseMotionListener.class);
            System.out.println(mouseMotionListeners.length);


            JOptionPane.showMessageDialog(null, sPane);
         }
      });
   }
}

Answer 1

您需要更改滚动窗格的首选大小，因为它会在完整的主面板上展开，当您单击最后一个元素（在空白区域中）时，它会被选中

更改： -

scrollPane.setPreferredSize(new Dimension(300,400));

到

scrollPane.setPreferredSize(new Dimension(300,100));

现在点击下面的列表不会改变选择。

它将如下所示 enter image description here

JList停止选择最后一项

1 个答案: