Need help with Vector parameter when invoking C dll from C#

**Willy Denoyette [MVP]** · Jun 13 '07, 09:25 AM

Re: Need help with Vector parameter when invoking C dll from C#

"Pucca" <Pucca@discussi ons.microsoft.c omwrote in message
news:8686DCD1-F569-415A-A7D7-D8DC600A1B54@mi crosoft.com...

The function that I'm trying to call through DLLImport has a parameter
that
has a C code's vector's Itrator to a structure. I Have marshalled the
structure in C# but how do I do the C type vector's Iterator in C#? The
problem is in the next line and the rest of the code is just additional
information on what I'm doing. Thanks.
CUnityDS.DE_ERR ORS errcode = CUnityDS.LibWra p.EncodeAsnUser (ref blob,
userContextData );
>
>
//In & out parameter for data structure for meetingBlob decoded
data
[StructLayout(La youtKind.Sequen tial, CharSet = CharSet.Unicode )]
public class CUserContextDat a
{
public int bWinLogOn = 0;
public int bUnifiedID = 0;
>
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String shell = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String homeDir = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String primaryGroupSID = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String LoginName = null;
>
public int symarkUID = 0; //Unified User ID
public int IID = 0; //Independant ID
public int Revision = 0;
}
>
public class LibWrap
{
//import the dll that decodes the user meetingBlob
[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS DecodeAsnUser(r ef Blob blob,
[In, Out]CUserContextDat a m);
>
[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS DecodeAsnGroup( ref Blob blob,
[In, Out]CGroupContextDa ta m);
>
[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS EncodeAsnUser(r ef Blob blob,
[In, Out]CUserContextDat a m);
>
CUnityDS.CUserC ontextData userContextData = new
CUnityDS.CUserC ontextData();
//put data into struc userContextData
CUnityDS.DE_ERR ORS errcode = CUnityDS.LibWra p.EncodeAsnUser (ref blob,
userContextData );
deNewContextObj ect.Properties["meetingBlo b"].Add((object)bl ob);//got
memory
corruption error here
>
>
>
int nBytes = Marshal.SizeOf( typeof(CUnityDS .Blob));
IntPtr ptr = Marshal.AllocHG lobal(nBytes);
>
// create an instance of the Blob structure
CUnityDS.Blob blob = new CUnityDS.Blob() ;
>
// copy and pin the structure to that location
Marshal.Structu reToPtr(blob, ptr, true);
>
// Pass it by reference
// OK, now it's time to "reconsitut e" the structure
blob = (CUnityDS.Blob) Marshal.PtrToSt ructure(ptr, typeof(CUnityDS .Blob));
>
//-------- This is the C code for the import method of the dll
extern "C" DE_ERRORS __declspec(dlle xport)EncodeAsn User(Blob** ppBlob,
vector <CUserContextDa ta>::iterator userDataIter)
{
_bstr_t temp;
AsnData* pAsn;
//int boolInt;
std::wstring wsUID;
>
>
if ( ( pAsn = AsnAlloc( NULL ) ) == NULL )
{
DbgLog( DL_ERROR, "Unable to allocate ASN.1 buffer" );
return DE_MEMORY_ALLOC ATION_FAILURE;
}
if ( !AsnPushTag(pAs n, (ASN_TAG$APPLIC ATION_START) ) )
goto failed;
>
if (!AsnWriteInteg er( pAsn, REVISION))
goto failed;
>
if(userDataIter->bUnifiedID)//use UID
{
if (!AsnWriteInteg er( pAsn, True) )
goto failed;
}
else //use indep ID
{
if (!AsnWriteInteg er( pAsn, False) )
goto failed;
}
if(userDataIter->IID == NULL)
{
if ( !AsnWriteGenera lString( pAsn, EMPTY_STRING))
goto failed;
}
else
{
_bstr_t bstrtUID = L"0"; //initilize the bstr
_itow(userDataI ter->IID, bstrtUID, 10);
>
if ( !AsnWriteGenera lString( pAsn, bstrtUID.operat or const char *()))
goto failed;
}
>
//WinUser name
if(userDataIter->bWinLogOn)
{
if (!AsnWriteInteg er( pAsn, True) )
goto failed;
>
}
else//use indep User Name
{
if (!AsnWriteInteg er( pAsn, False) )
goto failed;
}
>
//Geco
if ( !AsnWriteGenera lString( pAsn, EMPTY_STRING))
goto failed;
>
//Shell
temp = userDataIter->shell.c_str( );
if ( !AsnWriteGenera lString( pAsn, temp.operator const char *()))
goto failed;
>
//Home Driectory
temp = userDataIter->homeDir.c_str( );
if ( !AsnWriteGenera lString( pAsn, temp.operator const char *()))
goto failed;
>
//Primary Group SID
temp = userDataIter->primaryGroupSI D.c_str();
if (!AsnWriteGener alString( pAsn, temp.operator const char *()))
goto failed;
>
if ( !AsnPopTag( pAsn ) )
goto failed;
*ppBlob = AsnExtractData( pAsn );
AsnFree( pAsn );
return DE_SUCCESS;
>
failed:
DbgLog(DL_ERROR , "Failed to encode ASN.1 message packet" );
AsnFree( pAsn );
return DE_ENCODE_MESSA GE_PACKET_FAILU RE;
}
>

Not sure what you are trying to achieve here, you are passing a structure to
a function who's expecting a stl::vector iterator (according it's function
signature), this can never work, but there is more, you aren't using this
parameter as iterator in the C++ code, so this will never compile.

Willy.

**=?Utf-8?B?UHVjY2E=?=** · Jun 13 '07, 04:45 PM

Re: Need help with Vector parameter when invoking C dll from C#

Hi Willy,
You're correct about this will not compile in C# correctly. I need help in
figuring out how to use and call this C++ function properly with the correct
paramenter type. The C++ function is
extern "C" DE_ERRORS __declspec(dlle xport)EncodeAsn User(Blob** ppBlob,
vector <CUserContextDa ta>::iterator userDataIter)

I have the structure CUserContextDat a declare correctly in C# already. But
how do I use C# code to call this fucntion? I think the Blob** is declared
correctly but how do I declare a vector::iterato r for the structure
CUserContextDat a as a parameter in C# to call this function? Thank you.
--
Thanks.

"Willy Denoyette [MVP]" wrote:

"Pucca" <Pucca@discussi ons.microsoft.c omwrote in message
news:8686DCD1-F569-415A-A7D7-D8DC600A1B54@mi crosoft.com...

The function that I'm trying to call through DLLImport has a parameter
that
has a C code's vector's Itrator to a structure. I Have marshalled the
structure in C# but how do I do the C type vector's Iterator in C#? The
problem is in the next line and the rest of the code is just additional
information on what I'm doing. Thanks.
CUnityDS.DE_ERR ORS errcode = CUnityDS.LibWra p.EncodeAsnUser (ref blob,
userContextData );

//In & out parameter for data structure for meetingBlob decoded
data
[StructLayout(La youtKind.Sequen tial, CharSet = CharSet.Unicode )]
public class CUserContextDat a
{
public int bWinLogOn = 0;
public int bUnifiedID = 0;

[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String shell = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String homeDir = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String primaryGroupSID = null;
[MarshalAs(Unman agedType.ByValT Str, SizeConst =
MAX_ADSPATH_CHA RS)]
public String LoginName = null;

public int symarkUID = 0; //Unified User ID
public int IID = 0; //Independant ID
public int Revision = 0;
}

public class LibWrap
{
//import the dll that decodes the user meetingBlob
[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS DecodeAsnUser(r ef Blob blob,
[In, Out]CUserContextDat a m);

[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS DecodeAsnGroup( ref Blob blob,
[In, Out]CGroupContextDa ta m);

[DllImport("Unit yDecodeAsnUser. dll", CharSet =
CharSet.Unicode )]
public static extern DE_ERRORS EncodeAsnUser(r ef Blob blob,
[In, Out]CUserContextDat a m);

CUnityDS.CUserC ontextData userContextData = new
CUnityDS.CUserC ontextData();
//put data into struc userContextData
CUnityDS.DE_ERR ORS errcode = CUnityDS.LibWra p.EncodeAsnUser (ref blob,
userContextData );
deNewContextObj ect.Properties["meetingBlo b"].Add((object)bl ob);//got
memory
corruption error here

int nBytes = Marshal.SizeOf( typeof(CUnityDS .Blob));
IntPtr ptr = Marshal.AllocHG lobal(nBytes);

// create an instance of the Blob structure
CUnityDS.Blob blob = new CUnityDS.Blob() ;

// copy and pin the structure to that location
Marshal.Structu reToPtr(blob, ptr, true);

// Pass it by reference
// OK, now it's time to "reconsitut e" the structure
blob = (CUnityDS.Blob) Marshal.PtrToSt ructure(ptr, typeof(CUnityDS .Blob));

//-------- This is the C code for the import method of the dll
extern "C" DE_ERRORS __declspec(dlle xport)EncodeAsn User(Blob** ppBlob,
vector <CUserContextDa ta>::iterator userDataIter)
{
_bstr_t temp;
AsnData* pAsn;
//int boolInt;
std::wstring wsUID;

if ( ( pAsn = AsnAlloc( NULL ) ) == NULL )
{
DbgLog( DL_ERROR, "Unable to allocate ASN.1 buffer" );
return DE_MEMORY_ALLOC ATION_FAILURE;
}
if ( !AsnPushTag(pAs n, (ASN_TAG$APPLIC ATION_START) ) )
goto failed;

if (!AsnWriteInteg er( pAsn, REVISION))
goto failed;

if(userDataIter->bUnifiedID)//use UID
{
if (!AsnWriteInteg er( pAsn, True) )
goto failed;
}
else //use indep ID
{
if (!AsnWriteInteg er( pAsn, False) )
goto failed;
}
if(userDataIter->IID == NULL)
{
if ( !AsnWriteGenera lString( pAsn, EMPTY_STRING))
goto failed;
}
else
{
_bstr_t bstrtUID = L"0"; //initilize the bstr
_itow(userDataI ter->IID, bstrtUID, 10);

if ( !AsnWriteGenera lString( pAsn, bstrtUID.operat or const char *()))
goto failed;
}

//WinUser name
if(userDataIter->bWinLogOn)
{
if (!AsnWriteInteg er( pAsn, True) )
goto failed;

}
else//use indep User Name
{
if (!AsnWriteInteg er( pAsn, False) )
goto failed;
}

//Geco
if ( !AsnWriteGenera lString( pAsn, EMPTY_STRING))
goto failed;

//Shell
temp = userDataIter->shell.c_str( );
if ( !AsnWriteGenera lString( pAsn, temp.operator const char *()))
goto failed;

//Home Driectory
temp = userDataIter->homeDir.c_str( );
if ( !AsnWriteGenera lString( pAsn, temp.operator const char *()))
goto failed;

//Primary Group SID
temp = userDataIter->primaryGroupSI D.c_str();
if (!AsnWriteGener alString( pAsn, temp.operator const char *()))
goto failed;

if ( !AsnPopTag( pAsn ) )
goto failed;
*ppBlob = AsnExtractData( pAsn );
AsnFree( pAsn );
return DE_SUCCESS;

failed:
DbgLog(DL_ERROR , "Failed to encode ASN.1 message packet" );
AsnFree( pAsn );
return DE_ENCODE_MESSA GE_PACKET_FAILU RE;
}

>
>
>
Not sure what you are trying to achieve here, you are passing a structure to
a function who's expecting a stl::vector iterator (according it's function
signature), this can never work, but there is more, you aren't using this
parameter as iterator in the C++ code, so this will never compile.
>
Willy.
>
>

**Willy Denoyette [MVP]** · Jun 13 '07, 08:45 PM

Re: Need help with Vector parameter when invoking C dll from C#

"Pucca" <Pucca@discussi ons.microsoft.c omwrote in message
news:42DED808-4BE8-4E06-94E5-EA8297734083@mi crosoft.com...

Hi Willy,
You're correct about this will not compile in C# correctly. I need help
in
figuring out how to use and call this C++ function properly with the
correct
paramenter type. The C++ function is
extern "C" DE_ERRORS __declspec(dlle xport)EncodeAsn User(Blob** ppBlob,
vector <CUserContextDa ta>::iterator userDataIter)
>
I have the structure CUserContextDat a declare correctly in C# already.
But
how do I use C# code to call this fucntion? I think the Blob** is
declared
correctly but how do I declare a vector::iterato r for the structure
CUserContextDat a as a parameter in C# to call this function? Thank you.
--

You can't call this function from C#, you can only pass an iterator from
C++. What you could do is implement a function in a C++ wrapper that takes
an array of type CUserContextDat a and convert this into a vector of type
CUserContextDat a, then you need to declare a vector iterator for this vector
and pass the iterator to the EncodeAsnUser function.

Willy.

**=?Utf-8?B?UHVjY2E=?=** · Jun 14 '07, 12:15 AM

Re: Need help with Vector parameter when invoking C dll from C#

Thanks Willy. I think maybe I'll try working on a new C code function
similar to the one with vector except that I would only need to pass in the
structure CUserContextDat a. This might be easier for me than the wrapper.
From C# I'm only encoding one user structure at a time and really don't need
the vector stuff. Thank you very much.
--
Thanks.

"Willy Denoyette [MVP]" wrote:

"Pucca" <Pucca@discussi ons.microsoft.c omwrote in message
news:42DED808-4BE8-4E06-94E5-EA8297734083@mi crosoft.com...

Hi Willy,
You're correct about this will not compile in C# correctly. I need help
in
figuring out how to use and call this C++ function properly with the
correct
paramenter type. The C++ function is
extern "C" DE_ERRORS __declspec(dlle xport)EncodeAsn User(Blob** ppBlob,
vector <CUserContextDa ta>::iterator userDataIter)

I have the structure CUserContextDat a declare correctly in C# already.
But
how do I use C# code to call this fucntion? I think the Blob** is
declared
correctly but how do I declare a vector::iterato r for the structure
CUserContextDat a as a parameter in C# to call this function? Thank you.
--

>
>
You can't call this function from C#, you can only pass an iterator from
C++. What you could do is implement a function in a C++ wrapper that takes
an array of type CUserContextDat a and convert this into a vector of type
CUserContextDat a, then you need to declare a vector iterator for this vector
and pass the iterator to the EncodeAsnUser function.
>
Willy.
>
>

Need help with Vector parameter when invoking C dll from C#

Need help with Vector parameter when invoking C dll from C#

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