Programate algo - Programming Blog/Blog de Programación

Spanish version / Versión en Español In the previous post, we saw how to trigger an event from a C++ native class which has a C++/CLI wrapper as an interface to .NET. We dealt with the general case in which we wish to pass non trivial information (a class or a struct) along with the event. Today we'll see the more simple case in which we just need to pass a float or some other basic CLR type. As expected, things are quite simpler. In the native class, just for convenience, define a pointer to function type. Both returnType and parameters should be basic CLR types. typedef <returnType> ( __stdcall * PFOnEventCallback )( <parameters> ); In the same class, declare a field of that type: PFOnEventCallback m_fireEvent; Still in the native class, go to where you wish to trigger the event: if (m_fireEvent) m_fireEvent( <parameters> ); (It's good practice to initialize m_fireEvent to 0 or NULL, your cho...

Spanish version / Versión en Español Imagine we want to trigger an event from a native class which has a C++/CLI wrapper as an interface to managed code (C#, VB.NET). And let's deal with the general case in which we desire to pass extra information along with the event, and said information is not inside a CLR basic type, that is one which both native and managed C++ understand (int, float, char, and so on). In the native class, declare, just for convenience, a pointer to function type: typedef <nativeReturnType> ( __stdcall * PFOnEventCallback )( <nativeParameters> ); Still in the native class, declare a field of the type declared in 1): PFOnEventCallback m_fireEvent; In the place in the native class where we want to trigger the event: if( m_fireEvent ) m_fireEvent( <nativeParameters> ); (This suggests you to initialize m_fireEvent to 0, or NULL if you prefer) Now we need a setter for m_...

Spanish version / Versión en Español Say we have the following code in a C++/CLI assembly: //Assembly A public ref class ManagedClass{ public: ManagedClass( const NativeClass &a ); } If we wish to invoke this constructor from another C++/CLI assembly, as in this case... //Assembly B ManagedClass^ AnotherManagedClass::Property::get(){ NativeClass temp; return gcnew ManagedClass( temp ); } ... when we try to compile Assembly B, we'll get a compile error saying that the constructor we're trying to call is private. But how is that possible, if we declared it public? The answer is here . To sum it up, the workaround is using the #pragma make_public(NativeClass) directive right below the #include for NativeClass. This makes NativeClass accesible to other C++/CLI assemblies.