PRB: Can't Create VB ActiveX Control with Embedded Licensed Ctrl (175325)
The information in this article applies to:
- Microsoft Visual Basic Professional Edition for Windows 6.0
- Microsoft Visual Basic Control Creation Edition for Windows 5.0
- Microsoft Visual Basic Professional Edition for Windows 5.0
This article was previously published under Q175325 SYMPTOMS
If you embed a licensed ActiveX control inside a Visual Basic ActiveX
control and then attempt to use it on another machine, the Visual Basic
ActiveX control can fail to instantiate.
CAUSE
By default, Visual Basic ActiveX controls do not support embedding licensed
controls.
RESOLUTION
There are two possible solutions:
- If you make the outer Visual Basic control licensed, embedded licensed
controls will be created successfully. You can turn on licensing by
selecting Project/<ProjectName> Properties, clicking the General tab and
checking "Require License Key."
-or-
- For a licensed control to support being instantiated in a Visual Basic
control, it needs to support the following interface GUID:
{0x6e6e9780, 0x165d, 0x11d0, {0xb3, 0xe6, 0x00, 0xa0, 0xc9, 0x0f,
0x27, 0x31}}
Visual Basic will call QueryInterface() on the embedded licensed control's
IClassFactory for the GUID above. If the embedded control's IClassFactory
::QueryInterface function returns S_OK and a pointer to the IUnknown
interface, Visual Basic will create the licensed control using the cached
license key.
STATUS
This behavior is by design.
MORE INFORMATION
If the outer Visual Basic control is converted to a licensed control, and
if the client/container creates the outer Visual Basic control dynamically
(via a function call), as opposed to inserting it into a dialog, a license
key will have to be passed to the function. Hosting licensed ActiveX
controls in Internet Explorer will also require a license key. See the
REFERENCES section of this article for more information.
When you use a licensed control in a non-ActiveX Control project, Visual
Basic caches the control's run-time license key as part of the compiled
program. When you run the program on a machine that doesn't have a design-
time license, Visual Basic will use the stored license key to instantiate
the licensed control.
Licensed controls that come with Visual Basic that cannot be used inside a
UserControl include Crystal(crystl32.ocx)and DBGrid(dbgrid32.ocx).
The common controls in COMCTL32.OCX are licensed but were written so you
can use them in a Visual Basic ActiveX control.
REFERENCES
For additional information, please see the following articles in the
Microsoft Knowledge Base:
151771 193025 159923
: SAMPLE: LICREQST.EXE Requesting a License Key from an Object
159923
: HOWTO: Using Licensed ActiveX Controls in Internet Explorer
193025
: BUG: Cannot Dynamically Add a Non-Licensed MFC Control
| Modification Type: | Major | Last Reviewed: | 11/18/2003 |
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| Keywords: | kbprb KB175325 |
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