Serves as the base for classes that represent operations performed on visible nodes.
public abstract class TreeListVisibleNodeOperation : TreeListOperation
Public MustInherit Class TreeListVisibleNodeOperation Inherits TreeListOperation
The Tree List control enables you to traverse through nodes without writing recursive code. This can be performed by calling methods of the TreeListNodesIterator object that can be accessed via the TreeList.NodesIterator property. Different methods of this class traverse through different sets of nodes. You can use them to visit each node within the control, each node from the specified collection together with their child nodes and each visible node within a predefined range.
When traversing through all nodes of the control or through a specified collection, the operation performed on nodes can be specified by any TreeListOperation descendant. The proper object must be transmitted to a method as the parameter, for this purpose. In this case, you can override the TreeListOperation.NeedsFullIteration property and the TreeListOperation.NeedsVisitChildren method of the base class to specify which nodes from the set need to be visited.
When traversing through the predefined range of visible nodes (using the TreeListNodesIterator.DoVisibleNodesOperation method), the operation performed on nodes can be specified by a descendant of the TreeListVisibleNodeOperation class. You cannot specify nodes that must be omitted when traversing. Thus, the TreeListVisibleNodeOperation class overrides the TreeListOperation.NeedsFullIteration property and the TreeListOperation.NeedsVisitChildren method of the base class. This is done to restrict overriding these members in descendants since they are not in effect.
The remainder of the functionality provided by the TreeListVisibleNodeOperation class is the same as that provided by its ancestor. Please see the TreeListOperation class description for details.