How Do I Create an Entry Point for a DLL?

[TC]

I'm using VB.NET 2005. I need to create a DLL containing a function
F(). A VB.NET application will reference the DLL by using a Declare
statement.

Declare Function F Lib "Foo.dll" (ByVal Woo As String) As Double

When I write the DLL and test it, however, I get a runtime error.

Unable to find an entry point named 'F' in DLL 'Foo.dll'.

Judging from the error, it sounds like I need to create an "entry
point" in my DLL. Can anyone tell me how to do that?

Please note that I have no control over the code which calls my
function. That code uses a Declare statement.
-TC

[Tom Shelton]

TC wrote:

I'm using VB.NET 2005. I need to create a DLL containing a function
F(). A VB.NET application will reference the DLL by using a Declare
statement.

Declare Function F Lib "Foo.dll" (ByVal Woo As String) As Double

When I write the DLL and test it, however, I get a runtime error.

Unable to find an entry point named 'F' in DLL 'Foo.dll'.

Judging from the error, it sounds like I need to create an "entry
point" in my DLL. Can anyone tell me how to do that?

You can't. Declare statements are used to interact with native dll's
not managed dll's, in other words, managed applications do not
reference managed dll's via a declare statement. You will need to
write your dll in a language that supports this - like C++, PowerBasic,
etc.

Of course, there may be hacks to do this, just as there were for
VB.CLASSIC. I haven't looked, nor would I ever suggest anyone did
this. It is just not the way the tool your using works.

--
Tom Shelton

[Michel Posseth [MCP]]

Hacks , for Vb classic ???

http://www.windowsdevcenter.com/pub/...reate_dll.html

i do not see somuch hack about it ,, i see it more as a undocumented feature
:-)

Haven`t tried it but it might also work in VB.Net
regards

Michel Posseth

"Tom Shelton" <to*@mtogden.comschreef in bericht
news:11*********************@h48g2000cwc.googlegro ups.com...

>
TC wrote:

>I'm using VB.NET 2005. I need to create a DLL containing a function
F(). A VB.NET application will reference the DLL by using a Declare
statement.

Declare Function F Lib "Foo.dll" (ByVal Woo As String) As Double

When I write the DLL and test it, however, I get a runtime error.

Unable to find an entry point named 'F' in DLL 'Foo.dll'.

Judging from the error, it sounds like I need to create an "entry
point" in my DLL. Can anyone tell me how to do that?

You can't. Declare statements are used to interact with native dll's
not managed dll's, in other words, managed applications do not
reference managed dll's via a declare statement. You will need to
write your dll in a language that supports this - like C++, PowerBasic,
etc.

Of course, there may be hacks to do this, just as there were for
VB.CLASSIC. I haven't looked, nor would I ever suggest anyone did
this. It is just not the way the tool your using works.

--
Tom Shelton

[TC]

Tom,

Thank you for the clear answer. I wrote the code in C++ and it works
well.

How can I know which languages support native DLLs and which support
managed DLLs? I used the Borland C++ compiler to generate my DLLs.
Could I have used Visual C++ .NET instead?

-TC
Tom Shelton wrote:

TC wrote:

I'm using VB.NET 2005. I need to create a DLL containing a function
F(). A VB.NET application will reference the DLL by using a Declare
statement.

Declare Function F Lib "Foo.dll" (ByVal Woo As String) As Double

When I write the DLL and test it, however, I get a runtime error.

Unable to find an entry point named 'F' in DLL 'Foo.dll'.

Judging from the error, it sounds like I need to create an "entry
point" in my DLL. Can anyone tell me how to do that?

You can't. Declare statements are used to interact with native dll's
not managed dll's, in other words, managed applications do not
reference managed dll's via a declare statement. You will need to
write your dll in a language that supports this - like C++, PowerBasic,
etc.

Of course, there may be hacks to do this, just as there were for
VB.CLASSIC. I haven't looked, nor would I ever suggest anyone did
this. It is just not the way the tool your using works.

--
Tom Shelton

[Herfried K. Wagner [MVP]]

"TC" <go*********@yahoo.comschrieb:

How can I know which languages support native DLLs and which support
managed DLLs? I used the Borland C++ compiler to generate my DLLs.
Could I have used Visual C++ .NET instead?

Yes, you could have used Visual C++ .NET to do that.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

[Michel Posseth [MCP]]

Have just tried it and No i can`t get it to run ,, so it doesn`t work ,,,,
or i am missing something
"Michel Posseth [MCP]" <MS**@posseth.comschreef in bericht
news:eg**************@TK2MSFTNGP06.phx.gbl...

>
Hacks , for Vb classic ???

http://www.windowsdevcenter.com/pub/...reate_dll.html

i do not see somuch hack about it ,, i see it more as a undocumented
feature :-)

Haven`t tried it but it might also work in VB.Net
regards

Michel Posseth

"Tom Shelton" <to*@mtogden.comschreef in bericht
news:11*********************@h48g2000cwc.googlegro ups.com...

>>
TC wrote:

>>I'm using VB.NET 2005. I need to create a DLL containing a function
F(). A VB.NET application will reference the DLL by using a Declare
statement.

Declare Function F Lib "Foo.dll" (ByVal Woo As String) As Double

When I write the DLL and test it, however, I get a runtime error.

Unable to find an entry point named 'F' in DLL 'Foo.dll'.

Judging from the error, it sounds like I need to create an "entry
point" in my DLL. Can anyone tell me how to do that?

You can't. Declare statements are used to interact with native dll's
not managed dll's, in other words, managed applications do not
reference managed dll's via a declare statement. You will need to
write your dll in a language that supports this - like C++, PowerBasic,
etc.

Of course, there may be hacks to do this, just as there were for
VB.CLASSIC. I haven't looked, nor would I ever suggest anyone did
this. It is just not the way the tool your using works.

--
Tom Shelton