PRB: "Library Not Registered" Error When Calling Method in ATL Server

ID: Q221792


The information in this article applies to:


SYMPTOMS

After changing the type library version in the .idl file, any method you call in an ATL COM object returns an error of 0x8002801D (TYPE_E_LIBNOTREGISTERED or "Library not registered").


CAUSE

For dual interfaces, the ATL Object Wizard generates code that derives your COM class from IDispatchImpl. IDispatchImpl's fourth and fifth arguments are default arguments that map to the major and minor versions of the type library. These default to version 1.0. ATL uses this version to call LoadRegTypeLib(), which fails with TYPE_E_LIBNOTREGISTERED if the version in the type library doesn't match.


RESOLUTION

Add the appropriate version number to the template arguments for IDispatchImpl and IProvideClassInfo2Impl, if you are deriving from this class. For example, to set the type library version number to 2.5, your class declaration might resemble the following:


class ATL_NO_VTABLE CMyControl : 
	public IDispatchImpl<IMyControl, &IID_IMyControl, &LIBID_MyControlLib, 2, 5>,
	public IProvideClassInfo2Impl<&CLSID_MyControl, NULL, &LIBID_MyControlLib, 2, 5>... 
If your class derives from CStockPropImpl instead of IDispatchImpl, you need to set the type library version number via member variables, because CStockPropImpl derives from IDispatchImpl but it doesn't provide any template arguments for setting the version number. The major and minor version numbers are actually stored in CComTypeInfoHolder::m_wMajor and CComTypeInfoHolder::m_wMinor. IDispatchImpl contains a CComTypeInfoHolder member called _tih. You can set the version number in your class constructor:

	CMyControl()
	{
		_tih.m_wMajor = 2;
		_tih.m_wMinor = 5;
	} 


STATUS

This behavior is by design.


MORE INFORMATION

The same problem may exhibit different symptoms in different containers depending on what you are doing:


REFERENCES

(c) Microsoft Corporation 1999, All Rights Reserved. Contributions by Samson Tanrena, Microsoft Corporation.

Additional query words:


Keywords          : kbActiveX kbATL kbAutomation kbCOMt kbCtrlCreate kbVC600 kbATL300 kbATL300faq 
Version           : WINDOWS:3.0
Platform          : WINDOWS 
Issue type        : kbprb 

Last Reviewed: April 30, 1999