Want to use an image instead of a text label to trigger the expanding/collapsing events of an "Atlas" CollapsiblePanel? You still use a "Label" control for the trigger, but you switch it up a bit by setting the "ExpandText" and "CollapseText" properties to the HTML code for an image, like this:
CollapsiblePanelProperties.ExpandedText = "<img src='\website\images\toggle_expand.gif' />"
CollapsiblePanelProperties.CollapsedText = "<img src='\website\images\collapsed_toggleExpand.gif' />"
It's the same trick you can use in DataGrids to create an image without an image control, and creates the desired effect, as shown below.
In a future post, I'll illustrate in detail how to combine several "Atlas" extenders to create a "Poor Man's Portal" control. I just need to clean up the code and make it a little more "elegant".