Question

I have a scenario with three entities:

• An interface with one method stub
• A class that inherits from `System::Windows::Forms::NativeWindow` and implements the interface
• A wrapper class that has a private member of the class type and a public property of the interface type. This class also has a `KeyDown` event member that’s to be invoked/raised from the window class

These are the files I’m using:

INativeWindow.h

#pragma  once
public interface class INativeWindow
{
    void Nothing();
};

CLINativeWindow.h

#pragma  once
ref class NWHolder;
public ref class CLINativeWindow : System::Windows::Forms::NativeWindow, INativeWindow
{
public:
    NWHolder^ Parent;
    virtual void  Nothing() sealed;
    void DoIt();
};

CLINativeWindow.cpp

#include "stdafx.h"
#include "CLINativeWindow.h"

void CLINativeWindow::Nothing()
{
    Console::Write("None");
}
void CLINativeWindow::DoIt()
{
    Parent->KeyDown(this, nullptr);
};

NWHolder.h

#pragma  once
#include "INativeWindow.h"
#include "CLINativeWindow.h"

public ref class NWHolder
{

internal:
    event System::Windows::Forms::KeyEventHandler^ KeyDown;
public:
    virtual property INativeWindow^ OwnNativeWindow
    {
        INativeWindow^ __clrcall get() sealed;
        void __clrcall set(INativeWindow^ value) sealed; 
    }

private:
    CLINativeWindow^ nativeWindow_;
};

NWHolder.cpp

#include "stdafx.h"
#include "NWHolder.h"


INativeWindow^ NWHolder::OwnNativeWindow::get()
{
    return nativeWindow_;
}

void NWHolder::OwnNativeWindow::set(INativeWindow^ value)
{
    nativeWindow_ = dynamic_cast<CLINativeWindow^>(value); 
}

At compile time, I get this error:
Error 1 error C3767: 'NWHolder::KeyDown::raise': candidate function(s) not accessible ..\NativeWindows\CLINativeWindow.cpp 10

Is there anything that can be done? I tried even #pragma make_public(System::Windows::Forms::KeyEventHandler) but it failed.

Answer 1

The ‘raise’ inner method of a C++/CLI event is always declared protected. Add a method on NWHolder named “FireKeyDownEvent”, and give it whatever accessibility you like.