java - 为 JTree 节点设置 Imageicon

Question

我创建了一个JTree. 我需要更改特定节点的图标。能够setIcon关闭和打开以及叶子节点，但我需要在我的JTree. 请对此有所了解。

Answer 1

如果您知道如何更改默认图标，您就会知道这发生在 TreeCellRenderer 中。您可以简单地实现自己的 TreeCellRenderer，它比 DefaultTreeCellRenderer 具有更高级的图标确定功能。

像这样的东西：

public class MyTreeCellRenderer implements TreeCellRenderer {

    private final DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();
    private final  Icon specialIcon;

    public MyTreeCellRenderer(Icon specialIcon) {
        this.specialIcon = specialIcon;
    }

    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
        defaultRenderer.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
        if (needsSpecialIcon(tree, value, selected, expanded, leaf, row, hasFocus)) {
            defaultRenderer.setIcon(specialIcon);
        }
        return defaultRenderer;
    }

    private boolean needsSpecialIcon(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
        // check condition for special icon here
        return false;
    }
}

这基本上将默认行为委托给 DefaultTreeCellRenderer，但如果您的特殊条件为真，则会覆盖图标。