TVItemChild[Node] - returns the descriptor of the first child node for the given Node (or 0 if the Node has no subordinates in the tree);

TVItemHasChildren[Node] is not just about checking that a Node has child nodes. It is possible to use this property to indicate to the window that the Node node "has" child nodes, and from that moment on, a "+" button will be displayed opposite this element, allowing you to expand this node, even if there were no subordinate nodes in it. At the same time, at the time of plowing, you can add these same nodes. This feature can be used to postpone the loading of those nested nodes that are not yet required for the future, and thereby increase the speed of the initial filling of the contents of the tree;

TVItemChildCount[Node] - returns the number of child nodes for a Node directly nested within it;

TVItemExpanded[Node] - Determines if the node is open. By assigning the value true to this property, you can ensure its expansion (false - closing);

TVItemExpandedOnce[Node] - returns true if the node has been expanded at least once (after which this flag can be cleared only by deleting all child nodes);

TVExpand(Node, flags) - expands or collapses the Node, depending on the flags. You can pass a combination of flags in the flags parameter:

•TVE_COLLAPSE - collapses the node;

•TVE_COLLAPSERESET - in addition to collapsing, removes children;

•TVE_EXPAND - opens the knot;

•TVE_TOGGLE - if the node is open, closes it, and if it is open, then it slams;

TVSort(Node) - Sorts the tree starting from the specified node. If 0 is passed as the Node parameter, the entire tree is sorted;