PtrToStructure killing pointers

I am using .NETCF 2.0.5238.0 and presently (as VS2005 is unavailable in
Germany) still VS .NET 2003

I am working on interop between an unsave C-written DLL and C#.

Now, in a constructor of a class I am trying to get a structure copied from
unsafe to a safe structure (class actually) using Marshal.PtrToStructure
(IntPtr, Object). Returning from here my pointer goes to 0. What am I missing?
I tried the same with Marshal.PtrToStructure (IntPtr, Type) and IntPtr is
not null thereafter (but as I am using it in the constructor I guess I need
to use the first one). Regardless which version is used, the managed
structure/class properly receives the values from the unmanaged side
Thanks ahead for any help!!
tb

PS: here's the code:
..
..
public IntPtr cp;
//constructor
public WrapCP()
{
cp = myUnsafeDll_new();
log.Debug("cp initialized " + (int)cp); // this confirms a non zero return
value
Marshal.PtrToStructure(cp,this); //this properly fills the struct/class
log.Debug("cp now " + (int)cp); // cp now points to 0
}

One addition:
saving the Pointer to an int and restoring it resolved the problem
int cp1=cp.ToInt32;
Marshal.....
cp = (IntPtr)cp1;
however I still think I am misisng something I don't understand yet,
so any feedback is truly welcome.....

"tb2000" wrote:
> I am using .NETCF 2.0.5238.0 and presently (as VS2005 is unavailable in
> Germany) still VS .NET 2003
>
> I am working on interop between an unsave C-written DLL and C#.
>
> Now, in a constructor of a class I am trying to get a structure copied from
> unsafe to a safe structure (class actually) using Marshal.PtrToStructure
> (IntPtr, Object). Returning from here my pointer goes to 0. What am I missing?
> I tried the same with Marshal.PtrToStructure (IntPtr, Type) and IntPtr is
> not null thereafter (but as I am using it in the constructor I guess I need
> to use the first one). Regardless which version is used, the managed
> structure/class properly receives the values from the unmanaged side
> Thanks ahead for any help!!
> tb
>
> PS: here's the code:
> .
> .
> public IntPtr cp;
> //constructor
> public WrapCP()
> {
> cp = myUnsafeDll_new();
> log.Debug("cp initialized " + (int)cp); // this confirms a non zero return
> value
> Marshal.PtrToStructure(cp,this); //this properly fills the struct/class
> log.Debug("cp now " + (int)cp); // cp now points to 0
> }
>
>

On Sun, 15 Jan 2006 14:04:01 -0800, tb2000
<tb2000@discussions.microsoft.com> wrote:

>I am using .NETCF 2.0.5238.0 and presently (as VS2005 is unavailable in
>Germany) still VS .NET 2003

You can order Visual Studio in Germany e.g. here:

http://www.zoschke.com/default.asp

Regards,
Gilles [MVP].

(Please reply to the group, not via email)

Thanks for the lead. but will this solve my problem?

Btw: the VS Edition I need is shipping Feb06 according to that website. I
will probably go and get a US version.


"Gilles Kohl [MVP]" wrote:

> On Sun, 15 Jan 2006 14:04:01 -0800, tb2000
> <tb2000@discussions.microsoft.com> wrote:
>
> >I am using .NETCF 2.0.5238.0 and presently (as VS2005 is unavailable in
> >Germany) still VS .NET 2003
>
> You can order Visual Studio in Germany e.g. here:
>
> http://www.zoschke.com/default.asp
>
> Regards,
> Gilles [MVP].
>
> (Please reply to the group, not via email)
>
>