JTree用法及JTree使用经验总结(转)

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JTree用法及JTree使用经验总结(转)

2013年08月29日 ⁄ 综合 ⁄ 共 5902字 ⁄ 字号小中大 ⁄ 评论关闭

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 " );

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();

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();

}

} ××××××××××××××××××××××××××××××××××××××××××××××

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

【上篇】字符串转换为浮点数时如何避免精度损失
【下篇】硬盘安装FC3的一波三折

作者: goddamn

该日志由 goddamn 于11年前发表在综合分类下，最后更新于 2013年08月29日.
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JTree用法及JTree使用经验总结(转)

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