java - Jtree getTreeCellRendererComponent 执行几次

Question

我遇到了自定义 TreeCellRenderer 的问题。当我单击一个节点时，可覆盖方法 getTreeCellRendererComponent 执行大约 4 次。有人对此有想法吗？提前致谢。

西蒙

我的代码:

    @Override
public Component getTreeCellRendererComponent(JTree tree, Object p_value,
        boolean selected, boolean expanded, boolean leaf, int row,
        boolean hasFocus) {
    super.getTreeCellRendererComponent(tree, p_value, selected, expanded,
            leaf, row, hasFocus);
    if (row != -1) {
        DefaultMutableTreeNode aNode = (DefaultMutableTreeNode) p_value;
        TreePath treePath;

        treePath = tree.getPathForRow(row);
        if (treePath == null) {
            return this;
        }
        // int pathCount = treePath.getPathCount();
        JLabel label = (JLabel) this;
        if (aNode.getUserObject() instanceof MlCompteMail) {
            traiteNomCompte((MlCompteMail) aNode.getUserObject(), label);
            // JTreeFactory treeFact = new JTreeFactory();
            // treeFact.refreshNode(treePath);

            return this;
        } else if (aNode.getUserObject() instanceof MlDossier) {
            traiteNomDossier((MlDossier) aNode.getUserObject(), label, leaf);
            // JTreeFactory treeFact = new JTreeFactory();
            // treeFact.refreshNode(treePath);
            return this;
        }
    }

    return this;
}

/**
 * @param value
 * @param treePath
 * @param label
 * @param p_leaf
 */
private void traiteNomDossier(MlDossier p_dossier, JLabel label,
        boolean p_leaf) {
    String nomDossier = p_dossier.getNomDossier();
    if (nomDossier.equals(EnDossierBase.BROUILLON.getLib())) {
        label.setIcon(IconeTreeFactory.getBrouillon());
    } else if (nomDossier.equals(EnDossierBase.CORBEILLE.getLib())) {
        label.setIcon(IconeTreeFactory.getCorbeille());
    } else if (nomDossier.equals(EnDossierBase.ENVOYES.getLib())) {
        label.setIcon(IconeTreeFactory.getEnvoye());
    } else if (nomDossier.equals(EnDossierBase.RECEPTION.getLib())) {
        label.setIcon(IconeTreeFactory.getReception());
    } else if (nomDossier.equals(EnDossierBase.SPAM.getLib())) {
        label.setIcon(IconeTreeFactory.getSpam());
    } else if (p_leaf) {
        label.setIcon(IconeTreeFactory.getDossierFerme());
    } else {
        label.setIcon(IconeTreeFactory.getDossierOuvert());
    }
    int unreadMess = p_dossier.getUnreadMessCount();
    if (unreadMess > 0) {
        label.setText(nomDossier + " (" + unreadMess + ")");
        label.setFont(Fontfactory.getTREE_FONT_GRAS());
    } else {
        label.setText(nomDossier);
        label.setFont(Fontfactory.getTREE_FONT_PLAIN());
    }
    return;
}

// }
// }

/**
 * @param value
 * @param label
 */
private void traiteNomCompte(MlCompteMail p_compteMail, JLabel label) {
    int unreadMess = p_compteMail.getUreadMessCount();
    if (unreadMess > 0) {
        label
                .setText(p_compteMail.getNomCompte() + " (" + unreadMess
                        + ")");
        label.setFont(Fontfactory.getTREE_FONT_GRAS());
    } else {
        label.setText(p_compteMail.getNomCompte());
        label.setFont(Fontfactory.getTREE_FONT_PLAIN());
    }
    label.setIcon(IconeTreeFactory.getDossierOuvert());

}

Answer 1

这可能不是问题；只要需要绘制单元格，就会调用该方法。您无法控制它。

所以将方法设计得非常高效，并确保它没有副作用，你就没有问题。