将JTree的每个节点设置成不同的图标

朱雀 2022-08-21 10:42 117阅读 0赞

import java.awt.Component;  
      
    import javax.swing.ImageIcon;  
    import javax.swing.JTree;  
    import javax.swing.tree.DefaultMutableTreeNode;  
    import javax.swing.tree.DefaultTreeCellRenderer;  
      
    /** 
     * 自定义树描述类,将树的每个节点设置成不同的图标 
     * @author RuiLin.Xie - xKF24276 
     * 
     */  
    public class MyDefaultTreeCellRenderer extends DefaultTreeCellRenderer  
    {  
        /** 
         * ID 
         */  
        private static final long   serialVersionUID    = 1L;  
      
        /** 
         * 重写父类DefaultTreeCellRenderer的方法 
         */  
        @Override  
        public Component getTreeCellRendererComponent(JTree tree, Object value,  
                boolean sel, boolean expanded, boolean leaf, int row,  
                boolean hasFocus)  
        {  
      
            //执行父类原型操作  
            super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf,  
                    row, hasFocus);  
      
            setText(value.toString());  
              
            if (sel)  
            {  
                setForeground(getTextSelectionColor());  
            }  
            else  
            {  
                setForeground(getTextNonSelectionColor());  
            }  
              
            //得到每个节点的TreeNode  
            DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;  
              
            //得到每个节点的text  
            String str = node.toString();         
              
            //判断是哪个文本的节点设置对应的值（这里如果节点传入的是一个实体,则可以根据实体里面的一个类型属性来显示对应的图标）  
            if (str == "a")  
            {  
                this.setIcon(new ImageIcon("treeimg/a.GIF"));  
            }  
            if (str == "b")  
            {  
                this.setIcon(new ImageIcon("treeimg/b.GIF"));  
            }  
            if (str == "c")  
            {  
                this.setIcon(new ImageIcon("treeimg/c.GIF"));  
            }  
      
            return this;  
        }  
      
    }

import java.awt.BorderLayout;  
    import javax.swing.JFrame;  
    import javax.swing.JScrollPane;  
    import javax.swing.JTree;  
    import javax.swing.tree.DefaultMutableTreeNode;  
    import javax.swing.tree.DefaultTreeModel;  
      
    public class TreeIconDemo extends JFrame  
    {  
      
        /** 
         * ID 
         */  
        private static final long   serialVersionUID    = 1L;  
          
        private JTree   tree;  
      
        /** 
         * Launch the application 
         *  
         * @param args 
         */  
        public static void main(String args[])  
        {  
            try  
            {  
                TreeIconDemo frame = new TreeIconDemo();  
                frame.setVisible(true);  
            }  
            catch (Exception e)  
            {  
                e.printStackTrace();  
            }  
        }  
      
        /** 
         * Create the frame 
         */  
        public TreeIconDemo()  
        {  
            super();  
            setBounds(100, 100, 500, 375);  
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
      
            final JScrollPane scrollPane = new JScrollPane();  
            getContentPane().add(scrollPane, BorderLayout.CENTER);  
      
            tree = new JTree();  
            scrollPane.setViewportView(tree);  
      
            //创建数据  
            DefaultTreeModel defaultTreeModel = createModel();  
              
            //设置数据  
            tree.setModel(defaultTreeModel);  
              
            //设置自定义描述类  
            tree.setCellRenderer(new MyDefaultTreeCellRenderer());  
        }  
      
        /** 
         * 创建树节点模型 
         * @return 
         */  
        public DefaultTreeModel createModel()  
        {  
            DefaultMutableTreeNode root = new DefaultMutableTreeNode("a");  
            DefaultMutableTreeNode b = new DefaultMutableTreeNode("b");  
            DefaultMutableTreeNode c = new DefaultMutableTreeNode("c");  
            root.add(b);  
            root.add(c);  
            return new DefaultTreeModel(root);  
        }  
      
    }