INFO: NODUALINTERFACE Entry is Placed in Registry by VFP 5.0 (158765)
The information in this article applies to:
- Microsoft Visual FoxPro for Windows 5.0
- Microsoft Visual FoxPro for Windows 6.0
This article was previously published under Q158765 SUMMARY
Some ActiveX controls can support early binding, that is, where the control
supports a dual interface (a combination of an IDispatch and a Vtable
interface). If an ActiveX control registers itself incorrectly as
supporting a dual interface, then it might produce incorrect error
messages. These errors may include Invalid Page Fault errors under
Windows 95 or Access Violation errors under Windows NT.
MORE INFORMATION
Some ActiveX controls might be incorrectly registered as supporting Vtable
binding. This might cause an error when you use an ActiveX control. Visual
FoxPro 5.0 addresses this error in the development environment by adding
the "NoDualInterface" key to the registry. This key lists three known
controls that can register themselves as supporting Vtable binding. Note
that there may be other Activex controls that register themselves as
supporting Vtable binding when, in fact, they do not. If you add them to
this list, they function properly.
When Visual FoxPro is used to build an .exe file, it does not add the
NoDualInterface key to the registry file upon installation. If an ActiveX
control does not perform correctly, use the SYS(2333) function to enable or
disable dual-interface support of an ActiveX control.
You can also build a .reg file and run it as a post-executable when you
install the .exe file. This adds the "NoDualInterface" key to the registry.
Or, you can write a program in Visual FoxPro that updates the registry.
REFERENCES
For more information about how to write a program in Visual FoxPro to
update the registry, please see the following article in the Microsoft
Knowledge Base:
135398 How To Write to the Windows Registry Using API Calls
For more information about early binding, please see the following article
in the Microsoft Knowledge Base:
138138 Three Binding Types (Late, ID, Early) Possible in VB for Apps
Currently, Visual FoxPro 5.0 is the only Microsoft product that supports
the early Vtable binding of an ActiveX control. To disable dual-interface
functionally of an ActiveX control, use the SYS(2333) function.
Modification Type: | Major | Last Reviewed: | 10/15/2003 |
---|
Keywords: | kbinfo kbsetup KB158765 |
---|
|