PInvoke RAS problem

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G

Guest

Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " & ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
 
Thanks Chris,

but i had used Integer, with the same result.
Native Exception: 0xc0000005

Also, if i dont send DWORD

DWORD WINAPI EnumEntries(LPWSTR lpstr)

i have a error in line

wcscpy(lpstr,szTmp);

My device is a Symbol PPC 2003.
Dll is developed with evc++ 4.0

Thanks.


Long in CF is 64-bit. In unmanaged code it's 32-bit. Use Integer instead

-Chris


ACP said:
Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
 
Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper
 
Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

Alex Feinman said:
Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org
ACP said:
Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
 
Post a *complete* code snippet. There's something wrong with what you're
doing.

-Chris


ACP said:
Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

Alex Feinman said:
Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org
ACP said:
Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
Click to expand...
 
Here is all my code.

I'm begining and the DLL only has one method.

Unmanaged Code

// RasConnect.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
//#include "stdlib.h"
//#include "tchar.h"
#include "ras.h"
#include "raserror.h"



BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}



DWORD EntradasRAS(LPWSTR lpstr, DWORD &count)
{
LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];


wcscpy(szTmp,_T(""));
//lpRasEntry = '\0';
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
MessageBox(NULL,lpRasEntry[dw].szEntryName,_T("Conexiones"),MB_OK |
MB_ICONWARNING);
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}

Managed code (VB)

Imports System.Runtime.InteropServices
Imports System.Text

Public Class ConexionRAS

#Region "Funciones P/Invoke RasConnect.dll"

<DllImport("RasConnect.dll")> _
Private Function EntradasRAS(ByVal value As StringBuilder, ByRef count
As Integer) As Integer
End Function

#End Region

Public Function GetEntradasRAS() As String
Dim lpszValue As New StringBuilder(255)
Dim dwCount As Integer
Dim ret As Integer

Try
MessageBox.Show("Antes")
ret = Me.EntradasRAS(lpszValue, dwCount)
MessageBox.Show("Despues")

If ret = 0 Then
If dwCount = 0 Then
GetEntradasRAS = ""
Else
GetEntradasRAS = lpszValue.ToString()
End If
Else
MsgBox("Error :" & ret, vbCritical, "Enumeration Entries")
GetEntradasRAS = ""
End If

Catch ex As Exception
MessageBox.Show("Error EnumDevicesRAS: " & ex.Message.ToString())
End Try

End Function

End Class


Result:
Native Exception (0xc0000005)

Thanks


Post a *complete* code snippet. There's something wrong with what you're
doing.

-Chris


ACP said:
Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

Alex Feinman said:
Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org
Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
Click to expand...
 
As I see, you are concatenating all entries name into szTmp and its size
is 255. Try to enlarge this buffer, it seems that you has the stack
overlfow.

PS:
And should say that it's a bad practice to store such buffers in the
stack... and instead of wcscat use wcsncat, see
(http://msdn.microsoft.com/library/d...tml/_crt_strncat.2c_.wcsncat.2c_._mbsncat.asp)

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
Here is all my code.

I'm begining and the DLL only has one method.

Unmanaged Code

// RasConnect.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
//#include "stdlib.h"
//#include "tchar.h"
#include "ras.h"
#include "raserror.h"



BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}



DWORD EntradasRAS(LPWSTR lpstr, DWORD &count)
{
LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];


wcscpy(szTmp,_T(""));
//lpRasEntry = '\0';
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
MessageBox(NULL,lpRasEntry[dw].szEntryName,_T("Conexiones"),MB_OK |
MB_ICONWARNING);
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}

Managed code (VB)

Imports System.Runtime.InteropServices
Imports System.Text

Public Class ConexionRAS

#Region "Funciones P/Invoke RasConnect.dll"

<DllImport("RasConnect.dll")> _
Private Function EntradasRAS(ByVal value As StringBuilder, ByRef count
As Integer) As Integer
End Function

#End Region

Public Function GetEntradasRAS() As String
Dim lpszValue As New StringBuilder(255)
Dim dwCount As Integer
Dim ret As Integer

Try
MessageBox.Show("Antes")
ret = Me.EntradasRAS(lpszValue, dwCount)
MessageBox.Show("Despues")

If ret = 0 Then
If dwCount = 0 Then
GetEntradasRAS = ""
Else
GetEntradasRAS = lpszValue.ToString()
End If
Else
MsgBox("Error :" & ret, vbCritical, "Enumeration Entries")
GetEntradasRAS = ""
End If

Catch ex As Exception
MessageBox.Show("Error EnumDevicesRAS: " & ex.Message.ToString())
End Try

End Function

End Class


Result:
Native Exception (0xc0000005)

Thanks


Post a *complete* code snippet. There's something wrong with what you're
doing.

-Chris


Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

:


Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org

Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
Click to expand...
 
Hi Sergey,

thanks for the link, but the problem is throw by the second parameter (DWORD).
I have execute this simple code with the same result.

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved)
{
return TRUE;
}

void Prueba(DWORD &numero)
{
//DWORD minumero = 5;
//numero = minumero;

numero = 5;
}


Imports System.Runtime.InteropServices

Public Class PruebaPInvoke

#Region "Funciones P/Invoke Pruebas.dll"

<DllImport("Pruebas.dll")> _
Private Sub Prueba(ByRef numero As Integer)
End Sub

#End Region

Public Function GetNumero() As Integer
Dim numeroprueba As Integer = 0

Try
Me.Prueba(numeroprueba)
MessageBox.Show(numeroprueba.ToString())

Catch ex As Exception
MessageBox.Show("Error GetNumero: " & ex.Message.ToString())
End Try

End Function

End Class

What is forgetting to me?

Thanks


Sergey Bogdanov said:
As I see, you are concatenating all entries name into szTmp and its size
is 255. Try to enlarge this buffer, it seems that you has the stack
overlfow.

PS:
And should say that it's a bad practice to store such buffers in the
stack... and instead of wcscat use wcsncat, see
(http://msdn.microsoft.com/library/d...tml/_crt_strncat.2c_.wcsncat.2c_._mbsncat.asp)

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
Here is all my code.

I'm begining and the DLL only has one method.

Unmanaged Code

// RasConnect.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
//#include "stdlib.h"
//#include "tchar.h"
#include "ras.h"
#include "raserror.h"



BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}



DWORD EntradasRAS(LPWSTR lpstr, DWORD &count)
{
LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];


wcscpy(szTmp,_T(""));
//lpRasEntry = '\0';
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
MessageBox(NULL,lpRasEntry[dw].szEntryName,_T("Conexiones"),MB_OK |
MB_ICONWARNING);
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}

Managed code (VB)

Imports System.Runtime.InteropServices
Imports System.Text

Public Class ConexionRAS

#Region "Funciones P/Invoke RasConnect.dll"

<DllImport("RasConnect.dll")> _
Private Function EntradasRAS(ByVal value As StringBuilder, ByRef count
As Integer) As Integer
End Function

#End Region

Public Function GetEntradasRAS() As String
Dim lpszValue As New StringBuilder(255)
Dim dwCount As Integer
Dim ret As Integer

Try
MessageBox.Show("Antes")
ret = Me.EntradasRAS(lpszValue, dwCount)
MessageBox.Show("Despues")

If ret = 0 Then
If dwCount = 0 Then
GetEntradasRAS = ""
Else
GetEntradasRAS = lpszValue.ToString()
End If
Else
MsgBox("Error :" & ret, vbCritical, "Enumeration Entries")
GetEntradasRAS = ""
End If

Catch ex As Exception
MessageBox.Show("Error EnumDevicesRAS: " & ex.Message.ToString())
End Try

End Function

End Class


Result:
Native Exception (0xc0000005)

Thanks


Post a *complete* code snippet. There's something wrong with what you're
doing.

-Chris



Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

:


Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org

Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
Click to expand...
 
You have forgot about extern keyword and dllexport in eVC side:

Pruebas.cpp:

extern "C" {
__declspec(dllexport) void Prueba(DWORD &numero)
{
numero = 5;
}
}

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}

for VB.NET forgot about Shared keyword:

<DllImport("Pruebas.dll")>
Private Shared Sub Prueba(ByRef numero As Integer)


Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
Hi Sergey,

thanks for the link, but the problem is throw by the second parameter (DWORD).
I have execute this simple code with the same result.

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved)
{
return TRUE;
}

void Prueba(DWORD &numero)
{
//DWORD minumero = 5;
//numero = minumero;

numero = 5;
}


Imports System.Runtime.InteropServices

Public Class PruebaPInvoke

#Region "Funciones P/Invoke Pruebas.dll"

<DllImport("Pruebas.dll")> _
Private Sub Prueba(ByRef numero As Integer)
End Sub

#End Region

Public Function GetNumero() As Integer
Dim numeroprueba As Integer = 0

Try
Me.Prueba(numeroprueba)
MessageBox.Show(numeroprueba.ToString())

Catch ex As Exception
MessageBox.Show("Error GetNumero: " & ex.Message.ToString())
End Try

End Function

End Class

What is forgetting to me?

Thanks


:

As I see, you are concatenating all entries name into szTmp and its size
is 255. Try to enlarge this buffer, it seems that you has the stack
overlfow.

PS:
And should say that it's a bad practice to store such buffers in the
stack... and instead of wcscat use wcsncat, see
(http://msdn.microsoft.com/library/d...tml/_crt_strncat.2c_.wcsncat.2c_._mbsncat.asp)

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
Here is all my code.

I'm begining and the DLL only has one method.

Unmanaged Code

// RasConnect.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
//#include "stdlib.h"
//#include "tchar.h"
#include "ras.h"
#include "raserror.h"



BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}



DWORD EntradasRAS(LPWSTR lpstr, DWORD &count)
{
LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];


wcscpy(szTmp,_T(""));
//lpRasEntry = '\0';
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
MessageBox(NULL,lpRasEntry[dw].szEntryName,_T("Conexiones"),MB_OK |
MB_ICONWARNING);
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}

Managed code (VB)

Imports System.Runtime.InteropServices
Imports System.Text

Public Class ConexionRAS

#Region "Funciones P/Invoke RasConnect.dll"

<DllImport("RasConnect.dll")> _
Private Function EntradasRAS(ByVal value As StringBuilder, ByRef count
As Integer) As Integer
End Function

#End Region

Public Function GetEntradasRAS() As String
Dim lpszValue As New StringBuilder(255)
Dim dwCount As Integer
Dim ret As Integer

Try
MessageBox.Show("Antes")
ret = Me.EntradasRAS(lpszValue, dwCount)
MessageBox.Show("Despues")

If ret = 0 Then
If dwCount = 0 Then
GetEntradasRAS = ""
Else
GetEntradasRAS = lpszValue.ToString()
End If
Else
MsgBox("Error :" & ret, vbCritical, "Enumeration Entries")
GetEntradasRAS = ""
End If

Catch ex As Exception
MessageBox.Show("Error EnumDevicesRAS: " & ex.Message.ToString())
End Try

End Function

End Class


Result:
Native Exception (0xc0000005)

Thanks


:



Post a *complete* code snippet. There's something wrong with what you're
doing.

-Chris




Thanks Alex,

but there has been no luck. I have a fatal exception 0x80000002 (Out of
Memory)
in line

wcscpy(lpstr,szTmp);

I dont know what is happening. Any idea is good received!!

Thanks.

:



Try zeroing the buffer you allocated for lpRasEntry before using it.
On the approach - it's your choice, but I find it much easier to P/Invoke
RasEnumEntries directly, without ever writing an unmanaged wrapper

--
Alex Feinman
---
Visit http://www.opennetcf.org


Hi group,

I have to pinvoke a RAS dll, but i have a native exception and
a dont know what are i doing incorret.

Unmanaged Code:
------------------------

DWORD WINAPI EnumEntries(LPWSTR lpstr, DWORD &count)
{

LPRASENTRYNAME lpRasEntry = NULL;
DWORD dwRes, dwSize, dwEntries, dw;
WCHAR szTmp[255];

wcscpy(szTmp,_T(""));
lpRasEntry = new RASENTRYNAME[20];
if(lpRasEntry == NULL)
{
return 1;
}
lpRasEntry[0].dwSize = sizeof(RASENTRYNAME);
dwSize = sizeof(RASENTRYNAME) * 20;
dwRes = RasEnumEntries(NULL, NULL, lpRasEntry, &dwSize, &dwEntries);

if (dwRes == 0)
{
count = dwEntries;
for(dw = 0; dw < dwEntries; dw++)
{
wcscat(szTmp,lpRasEntry[dw].szEntryName);
if (dw != dwEntries)
wcscat(szTmp,_T(","));
}

//wcsncpy(lpstr, szTmp, 255);
wcscpy(lpstr,szTmp);
}

delete [] lpRasEntry;
return dwRes;
}


Managed Code (VB):
------------------------

<DllImport("DllPrueba.dll")> _
Private Function EnumEntries(ByVal lpszValue As StringBuilder, ByRef
dwCount as Long) As Long
End Function

...........

Dim szValue As New StringBuilder(255)
Dim dwCount As Long
Dim ret As Long

Try

ret = EnumEntries(szValue, dwCount)

MessageBox.Show("Resultado: " & szValue.toString())

Catch ex As Exception
MessageBox.Show("Error EnumEntriesRAS: " &
ex.Message.ToString())
End Try

I'm using StringBuilder with LPWSTR and ByRef with DWORD&.
Where they are the error(s)?

Thanks.
Click to expand...
Click to expand...
Click to expand...
 
Hi Sergery,

thanks, it is running!!.

But I do not understand where is the problem. I have a .def file where i
export my methods. I have always thought, that .def file and extern clause
were equivalent.

Where i can find information about it??

Thanks to all for your responses.
 
Hi ACP,

I'd like to have a copy of your RAS Dll if you don't mind. It's for personal
use. My e-mail is (e-mail address removed) .

Thanks in advance.
 
Hi Ray,

I developed the dll but it is property of our client, I am sorry.

Your device is PPC or WinCE??
What funcionality are you looking for??
In our dll we used, in addition to RAS, connection manager and RIL. I (and
this group) can help you to develop your own dll with RAS.

If it can help you, you have small RAS DLLs here:

http://www.codeppc.com/evc/index.htm

Once again, i am sorry. Excuse me.

Regards

ACP
 
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