Handling exception from unmanaged dll in C#
- by StuffHappens
Hello.
I have the following function written in C#
public static string GetNominativeDeclension(string surnameNamePatronimic)
{
if(surnameNamePatronimic == null)
throw new ArgumentNullException("surnameNamePatronimic");
IntPtr[] ptrs = null;
try
{
ptrs = StringsToIntPtrArray(surnameNamePatronimic);
int resultLen = MaxResultBufSize;
int err = decGetNominativePadeg(ptrs[0], ptrs[1], ref resultLen);
ThrowException(err);
return IntPtrToString(ptrs, resultLen);
}
catch
{
return surnameNamePatronimic;
}
finally
{
FreeIntPtr(ptrs);
}
}
Function decGetNominativePadeg is in unmanaged dll
[DllImport("Padeg.dll", EntryPoint = "GetNominativePadeg")]
private static extern Int32 decGetNominativePadeg(IntPtr surnameNamePatronimic,
IntPtr result, ref Int32 resultLength);
and throws an exception:
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
The catch that is in C# code doesn't actually catch it. Why? How to handle this exception?
Thank you for your help!
UPDATED
private static IntPtr[] StringsToIntPtrArray(params string[] strs)
{
IntPtr[] ptrs = new IntPtr[strs.Length + 1];
for(int i = 0; i < ptrs.Length - 1; i++) ptrs[i] = StringToIntPtr(strs[i]);
ptrs[ptrs.Length - 1] = Marshal.AllocHGlobal(m_MaxResultStringBufSize);
return ptrs;
}
