Optional URL to the background of this item.
The URL to the optional background image of this item. Default value is null.
The action taken when setting this value depends on whether the item is already a member of a viewer (it has been added to Items). If the item is not part of a viewer, then the value of BackImageUrl will be set with the new value and the actions described below will not occur until the item is added to a viewer.
When setting the value of this property (or adding an item to the viewer's Items), the viewer will load the new image in similar fashion to Url except the using ImageViewerItemChangedReason.BackImageUrl for the ItemChanged and ItemError events.
For more information, refer to Image Viewer Items.
Medical Web Viewer .NET