Question

我有这个错误，在填充JList之后，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。

任何人都可以帮我弄清楚吗？

谢谢＆amp;的问候，

Answer 1

选择ListSelectionEvents时会分派

2 JList - 在选择事件期间和之后另一个ListSelectionEvent。来自How to Write a List Selection Listener

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

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java swing jlist addListSelectionListener ListSelectionListener调用两次

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