Question

我有一些动态树。而现在我需要实现一些功能，每次只需点击节点就会发生这种功能。（我的意思是只有一次点击节点，“使它成为蓝色”）

** EDIT2：**我使用beanTreeView和openide

如何实现此操作的侦听器？

编辑 - 添加伪代码

public class MyNode extends AbstractNode{ //openide package
   private String name;

   public MyNode(String nameOfNode){
       super (new Children.LEAF);
       name = nameOfNode;
   }
   ....
   ....
}

public class IWantNameOfSelectedNode extends JPanel{   
    private JLabel jLnameOfNode;

   public IWantNameOfSelectedNode(){
       jLnameOfNode.setText("wiating for node selection");
   }

现在，我需要将所选节点的名称添加到jLabel，并在每次选择节点时更改它。

Answer 1

假设您正在使用Swing JTree类，则应定义TreeSelectionListener并将其添加到基础TreeModel。如果您希望使用ActionListener，则需要编写一些适配器代码，以便将TreeSelectionEvent转换为ActionEvent s（尽管这实际上是毫无意义的）。

示例

/** * Adapter class responsible for translating TreeSelectionEvents into * ActionEvents. */ public class TreeSelectionAdapter implements TreeSelectionListener { private final AtomicInteger nextId = new AtomicInteger(0); // Prefer CopyOnWriteArrayList to avoid ConcurrentModificationException if an // ActionListener removes itself as a listener during notification. private final CopyOnWriteArrayList<ActionListener> listeners; public TreeSelectionAdapter() { this.listeners = new CopyOnWriteArrayList<ActionListener(); } public void addActionListener(ActionListener l) { this.listeners.add(l); } public void removeActionListener(ActionListener l) { this.listeners.remove(l); } public void valueChanged(TreeSelectionEvent evt) { // Create new ActionEvent which corresponds to incoming TreeSelectionEvent // and notify registered ActionListeners. ActionEvent aEvt = new ActionEvent(evt.getSource(), nextId.getAndIncrement(), "selectionChanged"); for (ActionListener listener : listeners) { listener.actionPerformed(listener); } } } TreeNode rootNode = createTreeModel(); // Create custom model JTree tree = new JTree(rootNode); // Install model into JTree. // Add adapter listener to underlying selection model. tree.getSelectionModel().addTreeSelectionListener(adapter); // Register ActionListener with adapter listener. adapter.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent evt) { System.err.println("Selection has changed in some way!"); } });

Answer 2

我假设它是一棵摇摆树。您可以通过使用CustomRenderer组件或使用TreeSelectionListener接口来实现此目的。

这个link有一个关于如何改变图标，背景等的高级示例的教程。您需要的是比这更简单的版本。

您感兴趣的代码是

public Component getTreeCellRendererComponent( JTree tree,
                    Object value, boolean bSelected, boolean bExpanded,
                            boolean bLeaf, int iRow, boolean bHasFocus )
    {
        // Find out which node we are rendering and get its text
        DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
        String  labelText = (String)node.getUserObject();

        this.bSelected = bSelected;

        // Set the correct foreground color
        if( !bSelected )
            setForeground( Color.black );
        else
            setForeground( Color.white );
            ....
    }

如何实现监听器？

2 个答案: