RadTreeView has two different render modes that can change the actual HTML markup that is rendered. They are exposed via the RenderMode property that can have three possible values - Classic, Auto and Lightweight. This functionality was introduced in the Q2 2015 version.
The possible options are:
Classic - this mode is the rendering that has been used before. It remains without changes and it is the default value of the property.
Lightweight - with this render mode, the control yields completely different markup making maximum use of CSS 3 and semantic HTML. This means that we have dropped the image gradients in favor of CSS gradients. As for the skins, the main goal of using the Lightweight render mode is that image gradients could be easily replaced by CSS gradients. Thus, the amount of data that the client browser should request is sensibly decreased.
Auto - this mode makes the control choose the appropriate rendering mode according to the used browser - Classic or Lightweight.
RadTreeView, as well as the other Telerik controls that utilize render modes, supports only one type of render mode per page. This includes mode being set for a standalone instance, and a programmatically created instance. All such controls must have the same RenderMode on a given page. This also includes instances from user controls and master pages.
There are two ways to configure the rendering mode of the controls:
- The property RenderMode of RadTreeView can be used to set the render mode of a particular instance of the control:
<telerik:RadTreeView RenderMode="Lightweight" ID="RadTreeView1" runat="server" > </telerik:RadTreeView>
RadTreeView1.RenderMode = Telerik.Web.UI.RenderMode.Lightweight;
RadTreeView1.RenderMode = Telerik.Web.UI.RenderMode.Lightweight
- The render mode for the RadTreeView control can be specified globally in web.config by adding an app key:
<appSettings> <add key="Telerik.Web.UI.TreeView.RenderMode" value="Lightweight" /> </appSettings>