动态更改JTree中特定节点的图标

我已经看到很多在树实例化期间更改节点图标的示例，但我想要一种方法可以在以后动态更改单个节点的图标。 所以，在我的主代码中，我将自定义渲染器添加到我的树中：

// Icon I want to set nodes to later ImageIcon checkIcon = new ImageIcon("check.jpg"); // Creates tree with my nodes JTree tree = new JTree(nodes.top); // Create custom renderer Scenario1Renderer renderer = new Scenario1Renderer(); // Set to single tree selection tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION); // Set tree to my custom renderer //renderer.setRendererIcon(greenIcon); tree.setCellRenderer(renderer); 

我在渲染器中的代码是

 public class Scenario1Renderer extends DefaultTreeCellRenderer { ImageIcon rendererIcon; public void setRendererIcon(ImageIcon myIcon){ this.rendererIcon = myIcon; }; public Component getTreeCellRendererComponent( JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) { Component ret = super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus); //setIcon( rendererIcon ) ; return ret; } 

所以，很明显，如果我设置了我的rendererIcon，它将使用我在树实例化期间传入的图标绘制我的所有节点。 我想要某种方法，可以在以后的程序执行中设置单个节点的图标。

Answer 1

您可以根据不同的条件设置不同的图标。 下面是一个更改所选节点图标的简单示例：

 import java.awt.Component; import javax.swing.Icon; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTree; import javax.swing.SwingUtilities; import javax.swing.UIManager; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.DefaultTreeCellRenderer; import javax.swing.tree.DefaultTreeModel; public class TestTree { private static void createAndShowUI() { JFrame frame = new JFrame(); final JTree tree = new JTree(buildDemoModel()); tree.setCellRenderer(new DefaultTreeCellRenderer() { private Icon loadIcon = UIManager.getIcon("OptionPane.errorIcon"); private Icon saveIcon = UIManager.getIcon("OptionPane.informationIcon"); @Override public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean isLeaf, int row, boolean focused) { Component c = super.getTreeCellRendererComponent(tree, value, selected, expanded, isLeaf, row, focused); if (selected) setIcon(loadIcon); else setIcon(saveIcon); return c; } }); tree.setVisibleRowCount(10); frame.add(new JScrollPane(tree)); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationByPlatform(true); frame.pack(); frame.setVisible(true); } private static DefaultTreeModel buildDemoModel() { DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); root.add(new DefaultMutableTreeNode("A")); root.add(new DefaultMutableTreeNode("B")); root.add(new DefaultMutableTreeNode("C")); return new DefaultTreeModel(root); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { createAndShowUI(); } }); } }