JAVA GUI学习 - JTree树结构组件学习 ***

  1 public class JTreeKnow extends JFrame

  2 {

  3     public JTreeKnow()

  4     {

  5         this.setBounds(300, 100, 400, 500);

  6         this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  7         

  8         //创建树的第一种方式

  9         JTree jTree = new JTree();

 10         this.add(jTree);

 11         

 12         //创建树的第二种方式：推荐

 13         //创建根节点

 14         DefaultMutableTreeNode defaultMutableTreeNode = new DefaultMutableTreeNode("根节点");

 15         //创建树模型

 16         DefaultTreeModel defaultTreeModel = new DefaultTreeModel(defaultMutableTreeNode);

 17         //创建树

 18         JTree jTree2 = new JTree(defaultTreeModel);

 19         //创建滚动面板

 20         JScrollPane jScrollPane = new JScrollPane(jTree2);

 21         this.add(jScrollPane);

 22         //添加子节点

 23         for(int i = 1; i < 3; i++)

 24         {

 25             DefaultMutableTreeNode defaultMutableTreeNode2 = new DefaultMutableTreeNode("第一阶子节点"+i);

 26             for(int j = 1; j < 4; j++)

 27             {

 28                 DefaultMutableTreeNode defaultMutableTreeNode3 = new DefaultMutableTreeNode("第二阶子节点"+i+j);

 29                 defaultMutableTreeNode2.add(defaultMutableTreeNode3);

 30             }

 31             defaultMutableTreeNode.add(defaultMutableTreeNode2);

 32         }

 33         

 34         //获取根节点

 35         DefaultMutableTreeNode defaultMutableTreeNode2 = (DefaultMutableTreeNode) defaultTreeModel.getRoot();

 36         //根据父节点索引+子节点索引找到节点

 37         DefaultMutableTreeNode defaultMutableTreeNode3 = (DefaultMutableTreeNode) defaultTreeModel.getChild(defaultMutableTreeNode2, 0);

 38         System.out.println(defaultMutableTreeNode3);

 39         //获取某一节点到顶级节点（根节点）之间所有的节点

 40         

 41         //获取某节点所对应的阶层

 42         int level = defaultMutableTreeNode3.getLevel();

 43         

 44         //刷新重新绘制节点数（重要）

 45         defaultTreeModel.reload();

 46         //获取所有节点：迭代器

 47         Enumeration<DefaultMutableTreeNode> nodes = defaultMutableTreeNode.children();

 48         //判断某节点是否是根节点、页节点isLeaf()

 49         ((DefaultMutableTreeNode)defaultMutableTreeNode.getChildAt(0)).isRoot();

 50         

 51         /*******************************************监听器****************************************/

 52         //

 53         /***************JTree的监听器**************/

 54         //绑定选项监听器

 55         //某节点被选中了

 56         jTree2.addTreeSelectionListener(new TreeSelectionListener()

 57         {

 58             @Override

 59             public void valueChanged(TreeSelectionEvent e)

 60             {

 61                 // TODO Auto-generated method stub

 62 //                System.out.println("节点被选择");

 63                 //获取选中的treePath,treePath即根节点至所选节点的集合

 64 //                System.out.println(tree.getSelectionPath());

 65 //                //获取节点集合的数量

 66 //                System.out.println(tree.getSelectionPath().getPathCount());

 67 //                //获取选中的节点对象

 68 //                System.out.println((DefaultMutableTreeNode)tree.getSelectionPath().getLastPathComponent());

 69                 

 70                 System.out.println(e.getPath().getLastPathComponent());

 71             }

 72         });

 73         //为降低程序的错误率，监听器addTreeWillExpandListener和监听器addTreeExpansionListener通常会同时搭配使用，

 74         //以确保程序菜单正常、正确打开

 75         //绑定数结展开折叠的监听器

 76         //节点被展开了

 77         jTree2.addTreeExpansionListener(new TreeExpansionListener()

 78         {

 79             /**

 80              * 展开事件

 81              */

 82             @Override

 83             public void treeExpanded(TreeExpansionEvent event)

 84             {

 85                 // TODO Auto-generated method stub

 86                 System.out.println(event.getPath().getLastPathComponent()+" 被展开");

 87             }

 88             /**

 89              * 折叠

 90              */

 91             @Override

 92             public void treeCollapsed(TreeExpansionEvent event)

 93             {

 94                 // TODO Auto-generated method stub

 95                 System.out.println(event.getPath().getLastPathComponent()+" 被折叠");

 96             }

 97         });

 98         

 99         //绑定树结构将要执行展开和折叠的监听器

100         //节点将被展开：通常使用本方法对节点进行动态的显示控制

101         jTree2.addTreeWillExpandListener(new TreeWillExpandListener()

102         {

103             /**

104              * 将被展开的事件

105              */

106             @Override

107             public void treeWillExpand(TreeExpansionEvent event)

108                     throws ExpandVetoException

109             {

110                 // TODO Auto-generated method stub

111                 System.out.println(event.getPath().getLastPathComponent()+" 将被展开");

112                 

113             }

114             /**

115              * 将被折叠的事件

116              */

117             @Override

118             public void treeWillCollapse(TreeExpansionEvent event)

119                     throws ExpandVetoException

120             {

121                 // TODO Auto-generated method stub

122                 System.out.println(event.getPath().getLastPathComponent()+" 将被折叠");

123             }

124         });

125     }

126     public static void main(String[] args)

127     {

128         JTreeKnow jTreeKnow = new JTreeKnow();

129         jTreeKnow.setVisible(true);

130     }

131 }