I was recently adding drop-files support to ClipFlair Studio, so I had to do some research on the related API that is available to Silverlight apps. Silverlight supports a limited set of Drag-and-Drop interaction with the operating system (supposedly for security reasons, but most probably because of the classic cross-platform implementation ...

While stepping through “ShowDialog()” method of OpenFileDialog with Visual Studio 2010 debugger, at the Silverlight code pictured below (for loading a ClipFlair window’s stored options), I got a “Dialogs must be user-initiated” exception. Same behaviour will be shown with SaveFileDialog too, every time you try to step through the “ShowDialog()” ...