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();
}
}