There are two ways to use sprites with the RadMenu for ASP.NET AJAX:
- Use the CssClass property and set the background of the rmText element, e.g.
| background: transparent url('sprite.gif') no-repeat 0 0;
- use Item Templates where you can specify the markup in whatever way you like. In fact, a similar approach is used in the Custom attributes example for RadComboBox.
While the first solution is simple and more robust, it depends heavily on the skin you have chosen, since some of the RadMenu skins use the rmText elements (to attach rounded corner backgrounds, etc.).
And just a side-note: when creating the sprite, I recommend to create it vertical (this way the maximum wasted space will be the height of the items).
the Telerik team