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();
}
}
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