Hello,
I am trying to call an old C++ COM DLL from .NET. I have done the following but it does not seem to work:
I added a Reference to the DLL, TERMINATORLib and am using the code shown below.
That code works fine until I call a function that takes Parameters.
protected void Page_Load(object sender, EventArgs e)
{
TERMINATORLib.getbyMemberI
it.myTestFunc2();
When I call this function:
int nCharType = it.returnChartype("9C5B442
I get the follwing error:
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Can anyone explain why I am getting this error?
Thanks,
Tony
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>> what kind of memory is being accessed?
com applications does not impose restrictions on the memory being accessed - it might be totally different from the applications allocated memory
but when it comes to .net security it does not allow to access such memory without security credientials or code access security being implemented
What are your function declarations? http://msdn.microsoft.com/
C++ DLL ("returnstring.dll"):
#include <windows.h>
#include <tchar.h>
int GetString(LPSTR buf, int nMaxCount)
{
TCHAR* pszText = _T( "Hi from unmanaged code");
int nLen = _tcslen(pszText);
if (nLen < nMaxCount)
{
_tcscpy(buf,pszText);
return nLen;
}
return 0;
}
C#
using System.Text; // for StringBuilder
public class ReturnStringDll{
[DllImport("returnstring.d
public static extern int GetString(StringBuilder buf, int nMaxCount);
}
StringBuilder cb = new StringBuilder(256);
ReturnStringDll.GetString(
You need DLLImport to import Unmanaged DLL functions in C#. Or you can create a Managed Interop DLL for your Unmanaged DLL.
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by: ragi0017Posted on 2009-02-27 at 06:07:15ID: 23755672
the most likely reason for this error is security permiission for the user under which the site is running
are you using impersonation
does this call to the com objects function execute ok
it.myTestFunc2();
what kind of memory is being accessed by
int nCharType = it.returnChartype("9C5B442
there is a very high chance that the code access security rules might get applied which are blocking your call and you getting that exception
http://msdn.microsoft.com/