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Render Modes

RadGrid has three different render modes that can change the actual HTML markup that is rendered.Those render modes are exposed via the RenderMode property that accepts the following values - Classic, Mobile, Lightweight and Auto.

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. In this mode tables and background images (in several sprites) are used to create the layout (including rounded corners and shadows).

  • Lightweight — this mode is supported since Q1 2015 version and emphasizes on semantic HTML and CSS3. It reduces the amount of markup the control renders and makes it easier to customize. This also reduces the number of image sprites required by the control and the other controls from the suite it uses. In addition, all table elements are removed from the layout of the control. All of this decreases the overall size and complexity of each skin, including custom ones.

  • Mobile — this mode is supported since Q3 2014 Beta release and with it, the control will change to create a user experience tailored to the device screen size.In this mode, RadGrid is mobile-friendly and its touch zones are bigger and easier to select.

  • Auto — this option will automatically decide how to render the control on a smartphone, tablet or desktop PC or notebook and will switch between different render modes depending on the used device and based on the user's browser. Further details can be found in the section below.

Important Notes about Render Mode

In Lightweight render mode RadGrid leverages font icons instead of images and now the ButtonType property in various tags within the grid provide the FontIconButton option. Since this will be the default option, there is a significant difference with the Classic render mode - for example, the edit command buttons generated by the AutoGenerateEditColumn will now be different both visually and programmatically than it was with the Classic render mode. This means that you shall cast the Control to ElasticButton instead of LinkButton:

protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
        if (e.Item is GridDataItem)
                GridDataItem item = (GridDataItem)e.Item;
                ElasticButton button = (ElasticButton)item["AutoGeneratedEditColumn"].Controls[0];
                button.ToolTip = "Edit Order " + item.GetDataKeyValue("OrderID");
Protected Sub RadGrid1_ItemDataBound(sender As Object, e As GridItemEventArgs)
    If TypeOf e.Item Is GridDataItem Then
        Dim item As GridDataItem = DirectCast(e.Item, GridDataItem)
        Dim button As ElasticButton = DirectCast(item("AutoGeneratedEditColumn").Controls(0), ElasticButton)
        button.ToolTip = "Edit Order " & item.GetDataKeyValue("OrderID")
    End If
End Sub

RadGrid and its child controls, as well as the other controls included in the Telerik® UI for ASP.NET AJAX suite that utilize render modes, support only one type of render mode per page.All such controls must have the same RenderMode on a given page. This also includes instances from user controls and master pages.

For the automatic RenderMode Auto detection to work, your project must reference the Telerik.Web.Device.Detection.dll assembly in your project. This mode makes each control choose the appropriate rendering mode according to the used browser and device - Classic, Lightweight or Mobile. The behavior of the affected controls depends also on the available render modes, for example in touch devices the mode will be changed automatically to Mobile if supported. If not, the mode will fall back until it meets the best mode that fits the environment. You can find a list with the controls that support alternative render modes in the Render Modes List help article.

The precedence is as follows:

  • If the web site is opened on a mobile device browser, the controls would try to render in Mobile render mode. If this is not supported for some controls, precedence goes over Lightweight, then Classic.
  • On desktop the controls would first try to render in Lightweight render mode, if not supported - only then they will fall back to Classic.
  • If a certain control does not support Mobile and Lightweight, it will be rendered in Classic render mode.

Since the Lightweight render mode makes the controls more responsive, lightweight and easy to customize, it is the chosen mode for further development. All new controls (like RadLabel), skins (like Material), features and support for new browsers will be developed only for the modern Lightweight rendering. These newer controls are lightweight by design and setting the RenderMode to Classic won't have any effect. Nevertheless, the Classic render mode will continue to be supported and kept stable.

Generally, there is also inherited Native option available in the RenderMode enumeration for each control from the entire toolset. However, it is meaningful only for a handful of the controls, for example RadComboBox, which causes it to render on the page as a select element with option elements representing its items. This comes handy on mobile devices, because selection would have the native mobile behavior. As many of the controls, especially RadGrid, are complex controls which do not have such specific HTML element equivalents, the Native render mode is not supported or have the same effect as Classic.

Setting Render Mode

There are two ways to configure the rendering mode of the controls:

  • Setting the RenderMode property in the markup as a string, or setting it in the code-behind with a member of the Telerik.Web.UI.RenderMode enum.Following is an example for setting the RenderMode property in the markup:
<telerik:RadGrid ID="RadGrid1" runat="server" RenderMode="Lightweight">
  • A global setting in the web.config file that will affect the entire application, unless a concrete value is specifiedfor a given control instance:
    <add key="Telerik.Web.UI.Grid.RenderMode" value="Lightweight" />

See Also

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