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Since your application is responsible for the graphical content of a UDO (User Defined Object), VPE can not store the graphical content of UDO's in VPE document files. However, VPE stores the lParam parameter - which is the numeric ID to identify the UDO during the UDO-Paint event - within the VPE document file. Therefore if you read a VPE document file with your application, VPE fires as usual the UDO-Paint event and in that moment you can paint it. As a result you can not use the common VPE file viewer VPEView to display or print files which contain UDO's. Instead you need to write your own viewer application which considers and displays the UDO's graphical contents. On our website you can download the full source code of VPEView in order to modify it.

As an alternative we propose not to use UDO's, but to create Metafiles or Bitmaps instead of UDO's and to import those into the VPE document.