>__declspec(dllexport) void GetAPtrToAnUnmanagedStruct( MyUnmanagedStruct *
>ptr);
>void GetAPtrToAnUnmanageStruct( MyUnmanagedStruct * ptr)
>{
> ptr = new MyUnmanagedStruct();
>}

>class MyUnmanagedStruct
>{
> int foo;
>}
>class StructOwner
>{
> MyUnmanagedStruct uStruct; // i would like this reference points to the
>unmanaged struct

>>class MyUnmanagedStruct
>>{
>> int foo;
>>}
>>class StructOwner
>>{
>> MyUnmanagedStruct uStruct; // i would like this reference points to
>> the
>>unmanaged struct
>
> You can never make a reference type variable point to something that
> isn't allocated off the managed GC heap. You'll have to make
> MyUnmanagedStruct a struct in the C# code instead and then either
> store the pointer as a "real" pointer (MyUnmanagedStruct* - requires
> use of unsafe code) or as an IntPtr.

> thanks Mattias but :
>
>>>class MyUnmanagedStruct
>>>{
>>> int foo;
>>>}
>>>class StructOwner
>>>{
>>> MyUnmanagedStruct uStruct; // i would like this reference points to
>>> the
>>>unmanaged struct
>>
>> You can never make a reference type variable point to something that
>> isn't allocated off the managed GC heap. You'll have to make
>> MyUnmanagedStruct a struct in the C# code instead and then either
>> store the pointer as a "real" pointer (MyUnmanagedStruct* - requires
>> use of unsafe code) or as an IntPtr.
>
>
> how can I convert (cast) the IntPtr coming from the unmanaged code to my
> unmanaged structure :
>
> ******************************************************
> c++
> ******************************************************
> __declspec(dllexport) void GetAPtrToAnUnmanagedStruct( MyUnmanagedStruct
> ** ptr);
> void GetAPtrToAnUnmanageStruct( MyUnmanagedStruct ** ptr)
> {
> *ptr = new MyUnmanagedStruct();
> }
> ******************************************************
> c#
> ******************************************************
> [dllImport]
> void GetAPtrToAnUnmanagedStruct( ref IntPtr ptr);
> struct MyUnmanagedStruct
> {
> int foo;
> }
> class StructOwner
> {
> IntPtr ptrToAnUnmanagedStructure;
> MyUnmanagedStruct localUnmanagedStructure;
>
> InitPtr()
> {
> GetAPtrToAnUnmanagedStruct( ref ptrToAnUnmanagedStructure);
> }
>
> RefreshLocalData()
> {
> localUnmanagedStructure = (MyUnmanagedStruct)
> ptrToAnUnmanagedStructure; /// how do I cast the IntPtr ????
> }
> }
>
> what I want to do is to have a memory zone shared between a unmanaged c++
> dll and a c# application.
> in another words, I want to have structure that can be seen and modified
> in both worlds.
> (I can't make a managed c++ wrapper).
>
> thanks
> Antoine
>
>
>