Help Calling A Function from a 32-bit non-.NET DLL

#11

On Jun 18, 2:22*pm, Tom Shelton <tom_shel... (AT) comcast (DOT) invalid> wrote:

Quote:

DaveWurtzsubmitted this idea :

On Jun 18, 8:47*am, Tom Shelton <tom_shel... (AT) comcast (DOT) invalid> wrote:
DaveWurtzformulated the question :

On Jun 7, 5:16*pm, "Herfried K. Wagner [MVP]" <hirf-spam-me-
h... (AT) gmx (DOT) at> wrote:
Am 08.06.2010 00:05, schriebDaveWurtz:
In my VB.NET application, I'm trying to call a function from a 32-bit,
non-.NET dll file and I'm having problems. *I believe I have the
correct signature for the dll with:
System.Runtime.InteropServices.DllImportAttribute( "asdHTMLCompare.dll")
*>[...] When I run this, I get the error:
An exception of type 'System.EntryPointNotFoundException' occurred in
ProductVision.Windows.Forms.dll but was not handled in user code.
Additional information: Unable to find an entry point named
'BuildCompositeFile' in DLL 'asdHTMLCompare.dll'.
Maybe the function has a different name. *You may want to use Dependency
Walker (<URL:http://www.dependencywalker.com/>) to examine the function
the DLL exports.

--
* M S * Herfried K. Wagner
M V P *<URL:http://dotnet.mvps.org/
* V B * <URL:http://dotnet.mvps.org/dotnet/faqs/
Thanks for the reply.

As suggested, I downloaded the Dependency Walker program and opened
the DLL. *In looking at the function I want to call and selecting
"Undecorate C++ Functions", this is what it shows:
int BuildCompositeFile(char *,char *,char *,char *,char *,char *,int)
Do I have the correct signature defined?
Thanks.
Dave

If the dll is exposing a decorated name, then you must alias the vb
declare to the decorated name....

--
Tom Shelton- Hide quoted text -

- Show quoted text -

I don't understand what you are saying. *Can you expand on this and/or
show an example?

By default a dll compiled in C++ will mangle the names - this is to
allow overriding of functions. * So, your function BuildCompositeFile
maybe exported as something like ?BuildCompositFile@@YXZ. *That isn't
probably the actual name - I the way names are mangaled or decorated
has *alot to do with the compiler, and the types being passed. *But the
point is, the entery point in the dll is probably NOT
BuildCompositeFile.

You can use dumpbin /exports on your dll to see the actual name table. *
So, say the name is as above, then you would need to add an alias to
your VB declare:

Declare Ansi Function BuildCompositFile Lib "asdHtmlCompare.dll" Alias
"?BuildCompositFile@@YXZ" (.....)

HTH

--
Tom Shelton- Hide quoted text -

- Show quoted text -

Thank you. This worked perfect!
Dave

#12

On Jun 18, 2:26*pm, "Herfried K. Wagner [MVP]" <hirf-spam-me-
h... (AT) gmx (DOT) at> wrote:

Quote:

Am 18.06.2010 20:03, schriebDaveWurtz:

If the dll is exposing a decorated name, then you must alias the vb
declare to the decorated name....

I don't understand what you are saying. *Can you expand on this and/or
show an example?

Use the name you see prior to choosing to undecorate the function.

--
* M S * Herfried K. Wagner
M V P *<URL:http://dotnet.mvps.org/
* V B * <URL:http://dotnet.mvps.org/dotnet/faqs/

Thank you. This worked perfect!
Dave

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Help Calling A Function from a 32-bit non-.NET DLL

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Re: Help Calling A Function from a 32-bit non-.NET DLL - 06-30-2010 , 02:33 PM

Re: Help Calling A Function from a 32-bit non-.NET DLL - 06-30-2010 , 02:33 PM