Dlls

OfficeUser · Joined: 02 Feb 2008 Posts: 16

On another VB website They had a list of Dlls for download. Each Dll had a
description and some instructions on how to use. Reading some of the
descriptions and instructions I noted that some required to be registered on
the Registry and some did not. Can someone explain why some do and some
don't and what determines when a Dll must be registered.

Thanks!!

Archived from group: microsoft>public>vb>winapi

Thorsten Albers · Joined: 04 Oct 2007 Posts: 756

OfficeUser schrieb im Beitrag
...
> On another VB website They had a list of Dlls for download. Each Dll had
a
> description and some instructions on how to use. Reading some of the
> descriptions and instructions I noted that some required to be registered
on
> the Registry and some did not. Can someone explain why some do and some
> don't and what determines when a Dll must be registered.

COM/ActiveX DLLs have to be registered. So-called 'standard' DLLs do not
have to be registed.
The reason:
Methods etc. of COM/ActiveX DLLs are accessed via the COM interface(s). COM
takes the information needed for this from the system's registry. Therefore
these DLLs have to be registered, i.e. the location of the DLL as well as
the information about the available COM interfaces etc. have to be written
to the system's registry. Any application which is able to handle COM can
e.g. access a method in a COM/ActiveX DLL without having to know anything
about its arguments and return value before.

Methods etc. of 'standard' DLLs are accessed via an export table which is
located in the DLL itself. So any application can get the information
needed directly from the DLL. To use e.g. a method from a 'standard' DLL it
is necessary to know all about it before it is called. This information
can't be retrieved from the DLL but has to be provided by other methods
(documentation, C/C++ header file, VB declare statement, etc.).

--
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THORSTEN ALBERS Universität Freiburg
albers@
uni-freiburg.de
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Michael C · Joined: 04 Oct 2007 Posts: 335

"Thorsten Albers" wrote in message $c8e9a7e0$9f01a8c0@xyz...
> COM/ActiveX DLLs have to be registered. So-called 'standard' DLLs do not
> have to be registed.

It's possible that some of the dlls are dot net dlls.

Michael