JTree用法及JTree使用經驗總結 import ?java.awt.Dimension;
import ?java.awt.Color;
import ?javax.swing.JFrame;
import ?javax.swing.JPanel;
import ?javax.swing.JScrollPane;
import ?javax.swing.JTree;
import ?javax.swing.BoxLayout;
import ?javax.swing.tree.TreePath;
import ?javax.swing.tree.DefaultMutableTreeNode;
import ?javax.swing.tree.DefaultTreeModel;
/*
JTree的構造函數:
JTree()
JTree(Hashtable?value)
JTree(Object[]?value)//只有這個構造函數可以創建多個根結點
JTree(TreeModel?newModel)
JTree(TreeNode?root)
JTree(TreeNode?root,?boolean?asksAllowsChildren)
JTree(Vector?value)

*/
public ? class ?JTreeDemo
{
? public ? static ? void ?main?(String[]?args)
?{


?? // 構造函數：JTree()
??JTree?example1? = ? new ?JTree();

?

??
?? // 構造函數：JTree(Object[]?value)
??Object[]?letters = ?{ " a " ,? " b " ,? " c " ,? " d " ,? " e " };
??JTree?example2? = ? new ?JTree?(letters);

?


?? // 構造函數：JTree(TreeNode?root)(TreeNode空)
?? // 用空結點創建樹
??DefaultMutableTreeNode?node1? = ? new ?DefaultMutableTreeNode(); // 定義樹結點
??JTree?example3? = ? new ?JTree?(node1); // 用此樹結點做參數調用?JTree的構造函數創建含有一個根結點的樹

?


?? // 構造函數：JTree(TreeNode?root)(同上,只是TreeNode非空)
?? // 用一個根結點創建樹
??DefaultMutableTreeNode?node2? = ? new ?DefaultMutableTreeNode( " Color " );
??JTree?example4? = ? new ?JTree?(node2); // 結點不可以顏色,默認為白面黑字
??example4.setBackground?(Color.lightGray);

?


?? // 構造函數：JTree(TreeNode?root,?boolean?asksAllowsChildren)(同上,只是TreeNode又有不同)
?? // 使用DefaultMutableTreeNode類先用一個根結點創建樹，設置為可添加孩子結點,再添加孩子結點
??DefaultMutableTreeNode?color? = ? new ?DefaultMutableTreeNode( " Color " ,? true );
??DefaultMutableTreeNode?gray? = ? new ?DefaultMutableTreeNode?( " Gray " );
??color.add?(gray);
??color.add?( new ?DefaultMutableTreeNode?( " Red " ));
??gray.add?( new ?DefaultMutableTreeNode?( " Lightgray " ));
??gray.add?( new ?DefaultMutableTreeNode?( " Darkgray " ));
??color.add?( new ?DefaultMutableTreeNode?( " Green " ));
??JTree?example5? = ? new ?JTree?(color);
??
??
??
??
?? // 構造函數：JTree(TreeNode?root)(同上,只是TreeNode非空)
?? // 通過逐個添加結點創建樹
??DefaultMutableTreeNode?biology? = ? new ?DefaultMutableTreeNode?( " Biology " );
??DefaultMutableTreeNode?animal? = ? new ?DefaultMutableTreeNode?( " Animal " );
??DefaultMutableTreeNode?mammal? = ? new ?DefaultMutableTreeNode?( " Mammal " );
??DefaultMutableTreeNode?horse? = ? new ?DefaultMutableTreeNode?( " Horse " );??mammal.add?(horse);??animal.add?(mammal);??biology.add?(animal);??JTree?example6? = ? new ?JTree?(biology);??horse.isLeaf();??horse.isRoot();?????? // 構造函數:JTree(TreeModel?newModel)?? // 用DefaultMutableTreeNodel類定義一個結點再用這個結點做參數定義一個用DefaultTreeMode?? // 創建一個樹的模型,再用JTree的構造函數創建一個樹 ????DefaultMutableTreeNode?root? = ? new ?DefaultMutableTreeNode?( " Root1 " );??DefaultMutableTreeNode?child1? = ? new ?DefaultMutableTreeNode?( " Child1 " );??DefaultMutableTreeNode?child11? = ? new ?DefaultMutableTreeNode?( " Child11 " );??DefaultMutableTreeNode?child111? = ? new ?DefaultMutableTreeNode?( " Child111 " );??root.add?(child1);?child1.add?(child11);?child11.add?(child111);????????DefaultTreeModel?model? = ? new ?DefaultTreeModel?(root);????JTree?example7? = ? new ?JTree?(model);???JPanel?panel? = ? new ?JPanel();??panel.setLayout?( new ?BoxLayout?(panel,?BoxLayout.X_AXIS));??panel.setPreferredSize?( new ?Dimension?( 700 ,? 400 ));??panel.add?( new ?JScrollPane?(example1)); // JTree必須放在JScrollPane上 ??panel.add?( new ?JScrollPane?(example2));??panel.add?( new ?JScrollPane?(example3));??panel.add?( new ?JScrollPane?(example4));??panel.add?( new ?JScrollPane?(example5));??panel.add?( new ?JScrollPane?(example6));??panel.add?( new ?JScrollPane?(example7));?????JFrame?frame? = ? new ?JFrame?( " JTreeDemo " );??frame.setDefaultCloseOperation?(JFrame.EXIT_ON_CLOSE);??frame.setContentPane?(panel);??frame.pack();??frame.show();?}}

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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為需要選中的節點
? TreePath visiblePath = new TreePath( ( (DefaultTreeModel) jtNetDevice.getModel()).
??????????????????????????????????????? getPathToRoot(chosen));
? 然后根據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、關于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);
?????????? }
?????? }
?? }

轉載于:https://www.cnblogs.com/fillim/p/4194831.html

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