Log In
[Expand]General Information
[Expand]WinForms Controls
[Collapse]ASP.NET Controls and MVC Extensions
 [Expand]What's Installed
 [Expand]Common Concepts
 [Expand]ASP.NET WebForms Controls
 [Collapse]ASP.NET MVC Extensions
  [Expand]Product Information
  [Expand]Getting Started
  [Expand]Common Concepts
  [Expand]Grid View
  [Expand]Tree List
  [Expand]Card View
  [Expand]Pivot Grid
  [Expand]Rich Text Editor
  [Collapse]Site Navigation and Layout
     Overview - TreeView
     [Collapse]Binding to Data
       Binding to Data Overview
       Data Binding Using Mapping Properties
       Automatic Data Binding
       Unbound Mode
       Virtual Mode
      Expanding and Collapsing Nodes
      Animation Effect
      Node Link Mode
      Check Box Support
    [Expand]Visual Elements
  [Expand]HTML Editor
  [Expand]Vertical Grid
  [Expand]Data Editors Extensions
  [Expand]Docking and Popups
  [Expand]File Management
  [Expand]Data and Image Navigation
  [Expand]Multi-Use Site Extensions
  [Expand]Query Builder
 [Expand]Redistribution and Deployment
  Get More Help
 [Expand]API Reference
[Expand]ASP.NET Bootstrap Controls
[Expand]ASP.NET Core Bootstrap Controls
[Expand]WPF Controls
[Expand]Xamarin Controls
[Expand]Windows 10 App Controls
[Expand]Office File API
[Expand]Report and Dashboard Server
[Expand]eXpressApp Framework
[Expand]CodeRush Classic
[Expand]Cross-Platform Core Libraries
[Expand]Tools and Utilities
 End-User Documentation

Virtual Mode

In addition to bound and unbound modes, the MVC TreeView can operate in a Virtual Mode, which significantly reduces a server's load and start-up time when working with complex or dynamically generated hierarchies. In a Virtual Mode, data is retrieved on the server in chunks upon client requests. In essence, child nodes are not created and initialized until their parent node is expanded for the first time. This allows you to efficiently use server resources and avoid retrieving all hierarchical data for the TreeView.

The Virtual Mode is automatically activated if the TreeViewExtension.BindToVirtualData method is called. The method requires a delegate of the TreeViewVirtualModeCreateChildrenMethod type as a parameter that enables you to create a list of immediate child nodes for a particular node. Once assigned, this delegate method is called whenever a node is expanded for the first time. The processed node is passed as the method's parameter. To indicate that a child node has no children, its TreeViewVirtualNode.IsLeaf property must be set to true.


The TreeViewSettings.SyncSelectionMode property affects the TreeView extension behavior in virtual mode.

Expanded Examples

Expanded See Also

Is this topic helpful?​​​​​​​