download a file using windows IStream

I'm implementing dragging a virtu开发者_如何学编程al file out of a website and onto the desktop with an activex control.

How do I create an IStream on my http url, so Windows can execute the drop?

The example I'm looking at uses SHCreateStreamOnFile to copy a local file; there must be an analogous function for other types of streams like http file download.

How about using the URL Moniker Functions. You can use the URLDownloadToFile (blocking function), or URLOpenPullStream (asynchronous).