JTree的使用实例

JTree的使用实例

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();
 }
}