一、JTree用法及JTree使用经验总结
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import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
/*
JTree的构造函数:
JTree()
JTree(Hashtable value)
JTree(Object[] value)// 只有这个构造函数可以创建多个根结点
JTree(TreeModel newModel)
JTree(TreeNode root)
JTree(TreeNode root, boolean asksAllowsChildren)
JTree(Vector value)
*/
public class JTreeDemo {
public static void main(String[] args) {
// 构造函数：JTree()
JTree example1 = new JTree();
// 构造函数：JTree(Object[] value)
Object[] letters = { " a ", " b ", " c ", " d ", " e " };
JTree example2 = new JTree(letters);
// 构造函数：JTree(TreeNode root)(TreeNode空)
// 用空结点创建树
DefaultMutableTreeNode node1 = new DefaultMutableTreeNode(); // 定义树结点
JTree example3 = new JTree(node1); // 用此树结点做参数调用 JTree的构造函数创建含有一个根结点的树
// 构造函数：JTree(TreeNode root)(同上,只是TreeNode非空)
// 用一个根结点创建树
DefaultMutableTreeNode node2 = new DefaultMutableTreeNode(" Color ");
// 结点不可以颜色,默认为白面黑字
JTree example4 = new JTree(node2);
example4.setBackground(Color.lightGray);
// 构造函数：JTree(TreeNode root, boolean
// asksAllowsChildren)(同上,只是TreeNode又有不同)
// 使用DefaultMutableTreeNode类先用一个根结点创建树，设置为可添加孩子结点,再添加孩子结点
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);
// 构造函数：JTree(TreeNode root)(同上,只是TreeNode非空)
// 通过逐个添加结点创建树
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();
// 构造函数:JTree(TreeModel newModel)
// 用DefaultMutableTreeNodel类定义一个结点再用这个结点做参数定义一个用DefaultTreeMode
// 创建一个树的模型,再用JTree的构造函数创建一个树
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必须放在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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// 数组件申明
private JTree jtNetDevice;
// 滚动面板申明
private JScrollPane jspTree;
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);
}
}
}
二、Swing组件---JTree
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import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
public class JTreeDemo {
public static void main(String[] args) {
// 构造函数：JTree()
JTree example1 = new JTree();
// 构造函数：JTree(Object[] value)
Object[] letters = { "a", "b", "c", "d", "e" };
JTree example2 = new JTree(letters);
// 构造函数：JTree(TreeNode root)(TreeNode空)
// 用空结点创建树
DefaultMutableTreeNode node1 = new DefaultMutableTreeNode();// 定义树结点
JTree example3 = new JTree(node1);// 用此树结点做参数调用 JTree的构造函数创建含有一个根结点的树
// 构造函数：JTree(TreeNode root)(同上,只是TreeNode非空)
// 用一个根结点创建树
DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Color");
JTree example4 = new JTree(node2);// 结点不可以颜色,默认为白面黑字
example4.setBackground(Color.lightGray);
// 构造函数：JTree(TreeNode root, boolean
// asksAllowsChildren)(同上,只是TreeNode又有不同)
// 使用DefaultMutableTreeNode类先用一个根结点创建树，设置为可添加孩子结点,再添加孩子结点
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);
// 构造函数：JTree(TreeNode root)(同上,只是TreeNode非空)
// 通过逐个添加结点创建树
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();// if this node allows children.
horse.isRoot();// true if this node is the root of its tree
// 构造函数:JTree(TreeModel newModel)
// 用DefaultMutableTreeNodel类定义一个结点再用这个结点做参数定义一个用DefaultTreeMode
// 创建一个树的模型,再用JTree的构造函数创建一个树
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root1");
DefaultMutableTreeNode child1 = new DefaultMutableTreeNode("Child1");
DefaultMutableTreeNode child11 = new DefaultMutableTreeNode("Child11");
DefaultMutableTreeNode child111 = new DefaultMutableTreeNode("Child111");
DefaultMutableTreeNode child1111 = new DefaultMutableTreeNode(
"Child1111");
root.add(child1);
child1.add(child11);
child11.add(child111);
child111.add(child1111);
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必须放在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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