JTree的一些惯用方法

JTree的一些常用方法

在实际开发过程中会经常使用JTree组件，平时会遇到这样或那样的问题，在此将偶得一点经验写下来，与大家共享，希望对大家有所帮助。　　private JTree jtNetDevice;//树组件申明　　private JScrollPane jspTree;//滚动面板申明1、初始化　　DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("root");　　jtNetDevice = new JTree(rootNode);　　jtNetDevice.setAutoscrolls(true);　　getTreeSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);//设置单选模式　　jspTree = new JScrollPane();　　jspTree.getViewport().add(jtNetDevice, null);　　2、三个经常使用的取值函数　　private DefaultTreeModel getTreeModel(){　　return (DefaultTreeModel)jtNetDevice.getModel();　　}　　private DefaultMutableTreeNode getRootNode(){　　return (DefaultMutableTreeNode)getTreeModel().getRoot();　　}　　private TreeSelectionModel getTreeSelectionModel(){　　return jtNetDevice.getSelectionModel();　　}　　3、根据node得到path：　　TreePath visiblePath = new TreePath(getTreeModel().getPathToRoot(node));　　4、根据Path展开到该节点　　jtNetDevice.makeVisible(visiblePath);　　5、根据path设定该节点选定　　jtNetDevice.setSelectionPath(visiblePath);　　6、选中节点的方法　　首先，根据节点得到树路径，其中chosen为需要选中的节点　　TreePath visiblePath = new TreePath( ( (DefaultTreeModel) jtNetDevice.getModel()).　　getPathToRoot(chosen));　　然后根据Path选中该节点　　jtNetDevice.setSelectionPath(visiblePath);　　7、滚动到可见位置　　jtNetDevice.scrollPathToVisible(visiblePath);　　8、给JTree添加右键弹出菜单　　void jtNetDevice_mouseReleased(MouseEvent e) {　　if (e.isPopupTrigger()) {　　jPopupMenu1.show(e.getComponent(), e.getX(), e.getY());//弹出右键菜单　　}　　}　　9、关于JTree的展开　　// 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、如何遍历JTree　　// 创建树　　JTree tree = new JTree();　　// 添加树节点......　　// 遍历所有节点　　visitAllNodes(tree);　　// 仅遍历展开的节点　　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);　　}　　}　　}