JTree用法及JTree使用经验总结

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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;//数组件申明
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);
?????????? }
?????? }
?? }
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