problem with mixing managed/unmanaged code in several assemblies

[Vasco Lohrenscheit]

Hello,

I have problems with pointers to unmanaged classes as parameters for
virtual methods, and then overwriting the virtual methods in other
assemblies:

//GUI.dll
#include "../Plugin/iPlugin.h" //unmanaged plugin interface header

public __gc PluginGui : public Windows::Forms::Form
{
public:

virtual void plugin(iPlugin* p)=0;
virtual iPlugin* plugin()=0;
};

and
//RenderAppGUI.dll

#include "../Test/Test.h" //unmanaged iPlugin interface implementation
public __gc TestGUI : public PluginGUI
{
public:
virtual void plugin(iPlugin* p)
{
_app = dynamic_cast<Test*>(p);
}

virtual iPlugin* plugin()
{
return _app;
}
private:
Test* _app;
};
If I load the RenderAppGUI.dll with Assembly::LoadFile and create a
TestGUI CreateInstance I get a TypeLoadException because no
implementation of plugin(iPlugin* p) and plugin() are found.

I guess the problem is that with the include the unmanaged types are
defined in the assembly but are seen as different types in the two
assemblies and therefore the plugin methods in TestGUI are not the
implementation for the abstract methods in PluginGUI.

But how do I fix that ?