This help article describes how RadAjaxLoadingPanel works with skins, shows a figure of the available skins, and describes how to work with transparency settings and the BackgroundPosition property.
As of Q1 2009, RadAjaxLoadingPanel supports skinning similar to all other controls in the UI for ASP.NET AJAX suite. You can change a RadAjaxLoadingPanel's skin by setting the Skin property to the name of the respective skin.
Unlike all other RadControls, for a RadAjaxLoadingPanel the Skin property's default value is "" (no skin). The main reason for this is backwards compatibility. If this was not the default setting, the appearance of all legacy loading panels will be spoiled and two loading images will appear.
Figure 1 shows the embedded skins and what they look like for the RadAjaxLoadingPanel . They are embedded in the Telerik.Web.UI.dll assembly as web resources. To use a built-in skin you only need to set the Skin property of the control. You can find built-in skins in this folder: "C:\Program Files\Progress\UI for ASP.NET AJAX RX YYYY\Skins".
Figure 1: This figure shows the RadAjaxLoadingPanel using each of the embedded skins.
The Material skin is available for the Lightweight RenderMode only. If you experience visual issues with it, make sure your controls are not using the default Classic mode.
If the Skin property is set, the loading panel will NOT hide the updated control entirely, because transparency is applied by default from the skin. You can change this behaviour by setting EnableSkinTransparency="false" . Setting the RadAjaxLoadingPanel control's Transparency property will increase the actual visible transparency if the skin transparency is not disabled.
When the Skin property is set, the RadAjaxLoadingPanel control will render two nested
The RadAjaxLoadingPanel's BackgroundPosition property enables the developer to position the loading image in the loading panel (Top , TopRight , TopLeft , CenterLeft , Center , CenterRight , BottomLeft , Bottom , BottomRight and None ). The default value is Center . Choosing None is useful in cases when the loading image is larger than the updated control (e.g. a textbox).
Setting the Skin globally in the web.config file
You can avoid setting the Skin property per each RadAjaxLoadingPanel instance and set it globally in the web.config file:
<appSettings> <add key="Telerik.Ajax.Skin" value="Metro" />
Apart from using the embedded skins, you can easily create a custom skin for a RadAjaxLoadingPanel . A code library example, demonstrates how to do that and provides some useful tips.