DLLImport and "First time exception" ?

  • Thread starter Thread starter Fabien Penso
  • Start date Start date
F

Fabien Penso

Hi.

I am trying to use the sipX stack from http://www.sipfoundry.org/ into a
c# project. In release mode it works fine, but in Debug mode when I call
the dll imported function I get a :

First-chance exception at 0x001a73c2 in Essai sipx.exe: 0xC0000005:
Access violation reading location 0x001a73c2.

Can someone point me to something about this error ? I can't find a way
to find what to do in such case. If I don't call the dll imported
functions it's ok.

Any idea ?
 
Fabien Penso said:
Hi.

I am trying to use the sipX stack from http://www.sipfoundry.org/ into a
c# project. In release mode it works fine, but in Debug mode when I call
the dll imported function I get a :

First-chance exception at 0x001a73c2 in Essai sipx.exe: 0xC0000005: Access
violation reading location 0x001a73c2.

Can someone point me to something about this error ? I can't find a way to
find what to do in such case. If I don't call the dll imported functions
it's ok.

Any idea ?
Click to expand...

No, you should post at least the function declarations (DllImport and the C
function declaration) the and the the code part that call's it.

Willy.
 
Willy said:
The C# code looks ok, time to start the debugger and step through the
sipxInitialize function.
Click to expand...

Yeah I would love to do so, but breakpoints doesn't stop anything, and
as you see in my code I put a catch _all_ exceptions and it makes no
differences.
 
Mattias said:
The functions seem to use the cdecl calling convention. Try specifying
that in the DllImport attribute.
Click to expand...

I just tried

[DllImport("sipXtapid.dll",CallingConvention=CallingConvention.Cdecl)]

but it makes no difference, still that first chance exception... :(
 
Fabien Penso said:
Mattias said:
The functions seem to use the cdecl calling convention. Try specifying
that in the DllImport attribute.
Click to expand...

I just tried

[DllImport("sipXtapid.dll",CallingConvention=CallingConvention.Cdecl)]

but it makes no difference, still that first chance exception... :(
Click to expand...

Sure you have to match the calling convention, and set Cdecl when you
function expects Cdecl, but this can never be the cause of the problem.

Willy.
 
Fabien Penso said:
Yeah I would love to do so, but breakpoints doesn't stop anything, and as
you see in my code I put a catch _all_ exceptions and it makes no
differences.
Click to expand...

You have to enable native code debugging when running in VS, or simply try
to call the function (the debug version) from a C++ program.


Willy.
 
Willy said:
You have to enable native code debugging when running in VS, or simply try
to call the function (the debug version) from a C++ program.
Click to expand...

Debug mode for unmanaged code _is_ enabled... :( I guess I need to do a
little C++ then to call it from C++ instead of C#. I got the feeling
I'll get no errors.
 
Back
Top