 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
VB Forum / COM / November 2003COM Components and Interfaces
Hi, Does anyone know of a way to find all COM components that implement a specific interface. For example, specify interface "Ixxxxxxx" or an IID and the result returned is an array of ProgIDs or CLSIDs. TIA, John > Does anyone know of a way to find all COM components that implement a > specific interface. > > For example, specify interface "Ixxxxxxx" or an IID and the result > returned is an array of ProgIDs or CLSIDs. The only way is to enumerate all the CLSIDs in the registry, instantiate each class and then query the objects for the interface. Why you want to do that?  SignatureEduardo A. Morcillo [MS MVP VB] http://www.mvps.org/emorcillo I am building a testing tool for testing COM components that I build. I was wanting to have the tool display a list of all COM components that have a class supporting a particular interface e.g. ITestComponent It's not a "must have feature", but a "would be nice feature". If it can't be done easily, then no worries. > Does anyone know of a way to find all COM components that implement a > specific interface. > > For example, specify interface "Ixxxxxxx" or an IID and the result > returned is an array of ProgIDs or CLSIDs. The only way is to enumerate all the CLSIDs in the registry, instantiate each class and then query the objects for the interface. Why you want to do that? SignatureEduardo A. Morcillo [MS MVP VB] http://www.mvps.org/emorcillo How does OLE View do it? In OLE View I am able to open a typelib and see the interfaces a coclass implements. I'm guessing that it can be done some how using the ITypeInfo and ITypeLib interfaces. Currently, I am able to get the name and CLSID of each coclass in a typelib using those interfaces. > Does anyone know of a way to find all COM components that implement a > specific interface. > > For example, specify interface "Ixxxxxxx" or an IID and the result > returned is an array of ProgIDs or CLSIDs. The only way is to enumerate all the CLSIDs in the registry, instantiate each class and then query the objects for the interface. Why you want to do that? SignatureEduardo A. Morcillo [MS MVP VB] http://www.mvps.org/emorcillo Hi John, > How does OLE View do it? In OLE View I am able to open a typelib and > see the interfaces a coclass implements. > > I'm guessing that it can be done some how using the ITypeInfo and > ITypeLib interfaces. Currently, I am able to get the name and CLSID > of each coclass in a typelib using those interfaces. Yeah, provided there is type information available, you can use the typelib API to parse it. You should check out Tim Tabor's tlb2xml [1], which generates an XML document from a typelibrary, with reasonably high fidelity. It's probably not very useful to you in and of itself, but the source code demonstrates a lot of typelib API goodies. Kim [1] http://www.cheztabor.com/tlb2xml/index.htm Thanks Kim. That link was useful. I have it sussed now. > Hi John, > [quoted text clipped - 15 lines] > > [1] http://www.cheztabor.com/tlb2xml/index.htm Weren't you interested in the opposite lookup? FYI, OleView does not do such a lookup - from an interface to public objects that implement it. It's easy to implement though - enumerate all subkeys to HKCR\CLSID, instantiate the objects and query them for the interface in question. Takes time of course... A type library cannot solve this problem either. An interface described in one type library may be implemented by coclasses described in many other type libraries. Worse yet, a coclass may not list it among its interfaces (type information is advisory only, it's not mandatory). To top it off, a public object not described in any type library may implement it too. Furthermore, many interfaces are not described in type libraries at all... Signature===================================== Alexander Nickolov Microsoft MVP [VC], MCSD email: agnickolov@mvps.org MVP VC FAQ: http://www.mvps.org/vcfaq ===================================== > How does OLE View do it? In OLE View I am able to open a typelib and see the > interfaces a coclass implements. [quoted text clipped - 12 lines] > each class and then query the objects for the interface. Why you want to do > that? Alexander, > Worse yet, a coclass may not list it among its > interfaces (type information is advisory > only, it's not mandatory). Good point, I forgot to mention that. It sounded like John was mainly interested in doing what OleView does, i.e. listing all interfaces for the coclass mentioned in the tlb. SignatureBest regards, Kim Gräsman |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.