// 更新子类群。
        private void _UpdateChildren()
        {
            Taxon currentTaxon = Common.CurrentTaxon;

            List <(Taxon, bool)> children = new List <(Taxon, bool)>();

            foreach (var child in currentTaxon.GetNamedChildren(true))
            {
                // 添加当前类群的具名子类群(若当前类群是并系群,则只添加未被排除的具名子类群)
                if (currentTaxon.Excludes.Count > 0)
                {
                    bool childIsExcludedByCurrent = false;

                    foreach (var exclude in currentTaxon.Excludes)
                    {
                        if (exclude.IsNamed)
                        {
                            if (child == exclude)
                            {
                                childIsExcludedByCurrent = true;

                                break;
                            }
                        }
                        else
                        {
                            foreach (var item in exclude.GetNamedChildren(true))
                            {
                                if (child == item)
                                {
                                    childIsExcludedByCurrent = true;

                                    break;
                                }
                            }
                        }
                    }

                    if (!childIsExcludedByCurrent)
                    {
                        children.Add((child, false));
                    }
                }
                else
                {
                    children.Add((child, false));
                }

                // 若具名子类群是并系群,添加并系群排除的类群
                foreach (var exclude in child.Excludes)
                {
                    if (exclude.IsNamed)
                    {
                        children.Add((exclude, true));
                    }
                    else
                    {
                        foreach (var item in exclude.GetNamedChildren(true))
                        {
                            children.Add((item, true));
                        }
                    }
                }
            }

            // 若当前类群是复系群,添加复系群包含的类群
            foreach (var include in currentTaxon.Includes)
            {
                if (include.IsNamed)
                {
                    children.Add((include, true));
                }
                else
                {
                    foreach (var item in include.GetNamedChildren(true))
                    {
                        children.Add((item, true));
                    }
                }
            }

            Common.UpdateTaxonList(taxonButtonGroup_Children, children);
        }