HOWTO: Detect DCOM Installation Under VFP 6.0

• Microsoft Visual FoxPro for Windows, version 6.0

SUMMARY

This article illustrates how to detect whether DCOM is installed in a Windows 95/98 or a Windows NT 4.0 machine from within Visual FoxPro 6.0.

MORE INFORMATION

An application created with a Top-Level form needs DCOM installed in order to work properly when the Visual FoxPro main desktop is suppressed in the Config.fpw with SCREEN=OFF.

With the code below, you can detect that DCOM is present. Based on this information, you can shut down the application if necessary.

#DEFINE HKEY_LOCAL_MACHINE  -2147483646
#DEFINE DCOMKEYSTRING 'SOFTWARE\Microsoft\OLE'
#DEFINE ENABLEDCOMKEY 'EnableDCOM'

SET CLASSLIB TO HOME()+"ffc/REGISTRY.VCX"
oReg=CREATEOBJECT('registry')
LOCAL lFoundDCOM
lFoundDCOM = .F.
IF oReg.OpenKey(DCOMKEYSTRING,HKEY_LOCAL_MACHINE,.F.) = 0
   LOCAL cValue
   cValue = ''
   IF oReg.GetKeyValue(ENABLEDCOMKEY,@cValue) = 0
      lFoundDCOM = !EMPTY(cValue)
   ENDIF
ENDIF
IF !lFoundDCOM
   MESSAGEBOX('DCOM not install on system')
ELSE
   MESSAGEBOX('DCOM install on system')
ENDIF 

REFERENCES

For additional information about exception errors terminating Top-Level form in Visual FoxPro applications, please see the following article in the Microsoft Knowledge Base:

Q193472 BUG: Exception Error Exiting Top-Level Form App in Windows 95

Additional query words: DCOM

Keywords : kbDCOM kbNTOS400 kbVFp600 kbWinOS95 kbWinOS98 kbFFC
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbhowto