《树节点渲染器示例》PPT课件.ppt

1、扩展DefaultTreeCellRenderer创建自己的树节点渲染器示例,何杨 2008/02/20,本文内容,本文将讲述如何扩展DefaultTreeCellRenderer创建自己的树节点渲染器。,原有方法，缺点：灵活性不高,/设定叶节点图标 IconleafIcon=newImageIcon(TreeViewPanel.class .getResource(/leaf.gif); /设定关闭状态节点图标 IconclosedIcon=newImageIcon(TreeViewPanel.class .getResource(/close.gif); /设定打开状态节点图标 Icono

2、penIcon=newImageIcon(TreeViewPanel.class .getResource(/open.gif); /取得树的渲染器 DefaultTreeCellRendererrenderer=(DefaultTreeCellRenderer)tree .getCellRenderer(); /设定叶节点图标 renderer.setLeafIcon(leafIcon); /设定关闭状态节点图标 renderer.setClosedIcon(closedIcon); /设定打开状态节点图标 renderer.setOpenIcon(openIcon);,刚才的代码无法实现以

3、下效果,扩展DefaultTreeCellRenderer创建自己的树节点渲染器,public class TreeNodeRenderer extends DefaultTreeCellRenderer private static final long serialVersionUID = 8532405600839140757L; / 數據庫圖標,頂層節點用 private static final Icon databaseIcon = new ImageIcon(TreeNodeRenderer.class .getResource(/database.gif); / 表圖標,第三層

4、節點用 private static final Icon tableIcon = new ImageIcon(TreeNodeRenderer.class .getResource(/leaf.gif); / 表空間關閉狀態圖標,關閉狀態的第二層節點用 private static final Icon tableSpaceCloseIcon = new ImageIcon(TreeNodeRenderer.class .getResource(/close.gif); / 表空間關閉狀態圖標,打開狀態的第二層節點用 private static final Icon tableSpaceO

5、penIcon = new ImageIcon(TreeNodeRenderer.class .getResource(/open.gif);,public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);

6、 / 取得節點 DefaultMutableTreeNode node=(DefaultMutableTreeNode)value; / 取得路徑 TreeNode paths = node.getPath(); / 按路径层次赋予不同的图标 if (paths.length = 3) setIcon(tableIcon); else if(paths.length = 2) / 按展開情況再賦予不同的圖標 if(expanded) setIcon(tableSpaceOpenIcon); else setIcon(tableSpaceCloseIcon); else if(paths.length =