JTree使用經驗總結 - [ ] - [ ]

private JTree jtNetDevice;//數組件申明
private JScrollPane jspTree;//滾動面板申明

1、初始化
    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("root");
    jtNetDevice = new JTree(rootNode);
    jtNetDevice.setAutoscrolls(true);
    getTreeSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);//設置單選模式
    jspTree = new JScrollPane();
    jspTree.getViewport().add(jtNetDevice, null);

2、三個經常使用的取值函數
  private DefaultTreeModel getTreeModel(){
    return (DefaultTreeModel)jtNetDevice.getModel();
  }

  private DefaultMutableTreeNode getRootNode(){
    return (DefaultMutableTreeNode)getTreeModel().getRoot();
  }
 
  private TreeSelectionModel getTreeSelectionModel(){
    return jtNetDevice.getSelectionModel();
  }
 

3、根據node得到path：
  TreePath visiblePath = new TreePath(getTreeModel().getPathToRoot(node));

4、根據Path展開到該節點
  jtNetDevice.makeVisible(visiblePath);

5、根據path設定該節點選定
  jtNetDevice.setSelectionPath(visiblePath);

6、選中節點的方法
  首先，根據節點得到樹路徑，其中chosen爲需要選中的節點
  TreePath visiblePath = new TreePath( ( (DefaultTreeModel) jtNetDevice.getModel()).
                                        getPathToRoot(chosen));
  然後根據Path選中該節點
  jtNetDevice.setSelectionPath(visiblePath);

7、滾動到可見位置
  jtNetDevice.scrollPathToVisible(visiblePath);

8、給JTree添加右鍵彈出菜單
  void jtNetDevice_mouseReleased(MouseEvent e) {
    if (e.isPopupTrigger()) {
      jPopupMenu1.show(e.getComponent(), e.getX(), e.getY());//彈出右鍵菜單
    }
  }

9、關於JTree的展開
   // If expand is true, expands all nodes in the tree.
   // Otherwise, collapses all nodes in the tree.
   public void expandAll(JTree tree, boolean expand) {
       TreeNode root = (TreeNode)tree.getModel().getRoot();
  
       // Traverse tree from root
       expandAll(tree, new TreePath(root), expand);
   }
   private void expandAll(JTree tree, TreePath parent, boolean expand) {
       // Traverse children
       TreeNode node = (TreeNode)parent.getLastPathComponent();
       if (node.getChildCount() >= 0) {
           for (Enumeration e=node.children(); e.hasMoreElements(); ) {
               TreeNode n = (TreeNode)e.nextElement();
               TreePath path = parent.pathByAddingChild(n);
               expandAll(tree, path, expand);
           }
       }
  
       // Expansion or collapse must be done bottom-up
       if (expand) {
           tree.expandPath(parent);
       } else {
           tree.collapsePath(parent);
       }
   }
 

10、如何遍歷JTree
   // 創建樹
   JTree tree = new JTree();
  
   // 添加樹節點......
  
   // 遍歷所有節點
   visitAllNodes(tree);
  
   // 僅遍歷展開的節點
   visitAllExpandedNodes(tree);
  
   // Traverse all nodes in tree
   public void visitAllNodes(JTree tree) {
       TreeNode root = (TreeNode)tree.getModel().getRoot();
       visitAllNodes(root);
   }
   public void visitAllNodes(TreeNode node) {
       // node is visited exactly once
       process(node);
  
       if (node.getChildCount() >= 0) {
           for (Enumeration e=node.children(); e.hasMoreElements(); ) {
               TreeNode n = (TreeNode)e.nextElement();
               visitAllNodes(n);
           }
       }
   }
  
   // Traverse all expanded nodes in tree
   public void visitAllExpandedNodes(JTree tree) {
       TreeNode root = (TreeNode)tree.getModel().getRoot();
       visitAllExpandedNodes(tree, new TreePath(root));
   }
   public void visitAllExpandedNodes(JTree tree, TreePath parent) {
       // Return if node is not expanded
       if (!tree.isVisible(parent)) {
           return;
       }
  
       // node is visible and is visited exactly once
       TreeNode node = (TreeNode)parent.getLastPathComponent();
       process(node);
  
       // Visit all children
       if (node.getChildCount() >= 0) {
           for (Enumeration e=node.children(); e.hasMoreElements(); ) {
               TreeNode n = (TreeNode)e.nextElement();
               TreePath path = parent.pathByAddingChild(n);
               visitAllExpandedNodes(tree, path);
           }
       }
   }