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Robin Rodricks
Robin Rodricks

Reputation: 113946

Can you use C++ libraries natively in a C++/CLI WinForms application?

You can create a VC++ Windows Forms project that runs on the CLR, which is essentially a .NET app written in C++. Can you use unmanaged C++ libraries directly from such a project? Does that mean that the library must compile and run under .NET? Or must you write CLR wrapper classes for such libraries and only those will be usable from the CLR app?

Upvotes: 0

Views: 1110

Answers (2)

Ben Voigt
Ben Voigt

Reputation: 283614

Using a smart pointer library makes it much simpler to manage allocation of native (not garbage collected) objects, which is surprisingly difficult in the presence of exceptions, multiple calls to Dispose(), forgetting to call Dispose(), etc.

Here's Dr_Asik's example, rewritten to use a smart pointer I wrote:

#include "clr_scoped_ptr.h"
#include "NativeClass.h"

public ref class NativeClassWrapper {
    clr_scoped_ptr<NativeClass> m_nativeClass;

public:
    NativeClassWrapper() m_nativeClass(new NativeClass()) {}
    // auto-generated destructor is correct
    // auto-generated finalizer is correct

    void Method() {
        m_nativeClass->Method();
    }
};

For string conversions, use the marshal_as class Microsoft provided for the purpose. Check out ildjarn's answer here: C++/CLI String Conversions

Upvotes: 1

corylulu
corylulu

Reputation: 3499

Yes. Here are some guides. Mixing CLI/C++ and native code. You don't need a wrapper to use them in CLI/C++. In fact, you use CLI/C++ and native code to create a wrapper.

http://www.technical-recipes.com/2012/mixing-managed-and-native-types-in-c-cli/

http://www.codeproject.com/Articles/35041/Mixing-NET-and-native-code

If you are actually trying to make a wrapper to use in C#, it should look something like this:

#include "NativeClass.h"

public ref class NativeClassWrapper {
    NativeClass* m_nativeClass;

public:
    NativeClassWrapper() { m_nativeClass = new NativeClass(); }
    ~NativeClassWrapper() { delete m_nativeClass; }
    void Method() {
        m_nativeClass->Method();
    }

protected:
    // an explicit Finalize() method—as a failsafe
    !NativeClassWrapper() { delete m_nativeClass; }
};

Refer to C++/CLI wrapper for native C++ to use as reference in C#

Upvotes: 1

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