アクションはキャンセルできます。
WebDataTree1.ClientEvents.NodeCollapsing = "WebDataTree_NodeCollapsing"
WebDataTree1.ClientEvents.NodeCollapsing = "WebDataTree_NodeCollapsing";
// The client event 'NodeCollapsing' takes two parameters sender and e // sender is the object which is raising the event // e is the DataTreeNodeEventArgs function WebDataTree_NodeCollapsing (sender ,e) { //Gets the node object that is collapsing var node = e.getNode(); //Gets the text of the node var nodeText = node.get_text(); if (!confirm("Are you sure you want to collapse the node '" + nodeText + "'?")) //Cancels the NodeCollapsing event e.set_cancel(true); }