FIX: Scribble File Extension Conflicts with Screen Savers

WINDOWS        | WINDOWS NT

The information in this article applies to:

• The Microsoft Foundation Classes (MFC), included with:

      - Microsoft Visual C++ for Windows, versions 1.50, 1.51, and 1.52
      - Microsoft Visual C++, 32-bit Edition, versions 2.0 and 2.1
  

SYMPTOMS

Creating or activating embedded or linked OLE objects-based files saved with the MFC server sample "Scribble" fails in unexpected ways. Two common scenarios are:

• When you attempt to insert an object into an OLE container using the Create from File option, instead of creating a new Scribble Document object and inplace activating it, the Packager is invoked and a package is created. Nothing appears to happen when you try to activate the package.
• While a Scribble Document is open in the Scribble application, you copy the contents to the clipboard, and attempt to paste link from an OLE container. The link is created and the container document's image of the link displays correctly. But after the container document is saved and both the container and Scribble applications are shut down, when you reopen the saved document, the container is unable to update or activate the link to the Scribble Document.

CAUSE

The .SCR file extension used by Scribble is associated with another file type, typically screen saver applications.

RESOLUTION

Change the file extension used by Scribble Documents to something that is not already associated with a file type, for example .SCB. After changing the file extension, you will need to run Scribble once in standalone mode so it can update the system registry.

The file extension can be changed by editing the string resource IDR_SCRIBTYPE in the Scribble application. Initially the string value is:

   \nScrib\nScrib\nScrib Files (*.scr)\n.SCR\nScribble.Document.1\n
      Scrib Document\nSCRI\nscri Files

   \nScrib\nScrib\nScrib Files (*.scb)\n.SCB\nScribble.Document.1\n
      Scrib Document\nSCRI\nscri Files

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Microsoft Visual C++, 32-bit edition, version 4.0.

MORE INFORMATION

MFC Applications can update the file associations maintained in the system registry by calling CWinApp::RegisterShellFileTypes(). However, RegisterShellFileTypes() does not replace an existing association. Thus when an association already exists for the .SCR file extension, nothing is added to the registry to indicate that Scribble should be used to create or edit these files.

This situation is most likely to occur on Windows 95, as .SCR files are associated with Screen Saver applications when Windows 95 is installed.