java swing jlist addListSelectionListener ListSelectionListener调用两次

Question

我有这个错误,填充JList后,我尝试检索所选项的值.但是当我这样做时,它会被调用两次.

这是我的代码:

 public CaveAdventureUI(CaveGame game) {
    initComponents();
    playerCarryItemModel = new DefaultListModel();
    caveCarryItemModel = new DefaultListModel();
    this.caveGame = game;
    this.world = game.getCaveWorld();
    listSelectionModel = this.jListCaveCarryItems.getSelectionModel();
    listSelectionModel.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    this.listSelectionModel.addListSelectionListener( new SharedListSelectionHandler());
    //for debug purpose,see the world grid in console
    game.drawCaves();
    //new JComboBox(Mood.values());
    createGridQuarePanels();
    //world.startGame(GameLevel.Beginner);
    update();
}


private class SharedListSelectionHandler implements ListSelectionListener {
    public void valueChanged(ListSelectionEvent listSelectionEvent) {
        ListSelectionModel lsm = (ListSelectionModel)listSelectionEvent.getSource();
         if (!lsm.isSelectionEmpty()) {
            Occupant opt = mapOccupants.get(Integer.toString(jListCaveCarryItems.getSelectedIndex()));
            System.out.println("selected index :" +jListCaveCarryItems.getSelectedIndex() +"[["+opt.getName()+"]]");
        }
    }
}

在上面的代码中,当我在jList:jListCaveCarryItems上进行选择时,它会触发SharedListSelectionHandler类.但是,当我单击JList时,它会打印出两次所选的值.

任何人都可以帮我搞清楚吗？

感谢和问候,

Answer 1

在选择事件期间和选择事件之后的另一个选择ListSelectionEvents时调度2 JList.从如何编写列表选择监听器

如果用户仍在操作选择,则isAdjusting标志为true,如果用户已完成更改选择,则为false.

因此,请确保ListSelectionEvent不调整该值.

public void valueChanged( ListSelectionEvent listSelectionEvent)  {  
  if ( !listSelectionEvent.getValueIsAdjusting() && !lsm.isSelectionEmpty()) {  
     Occupant opt = ...
     ...
  }  
}