NodeHovered プロパティ

// The client event 'NodeHovered' takes two parameters sender and e
// sender  is the object which is raising the event
// e is the DataTreeNodeEventArgs
//Fires only when EnableHotTracking property is set to True on the server
function WebDataTree_NodeHovered(sender, e) {

    //Gets the node object that has mouse on it
    var node = e.getNode();

    //Gets the text of the node
    var nodeText = node.get_text();

    alert("Mouse is on the node '" + nodeText + "'!");

}