Problem implementing an interface
CodeGuru Home VC++ / MFC / C++ .NET / C# Visual Basic VB Forums Developer.com
Results 1 to 4 of 4

Thread: Problem implementing an interface

  1. #1
    Join Date
    Aug 2009
    Location
    Finally back in Alaska
    Posts
    141

    Problem implementing an interface

    Hello all,

    I am trying to port over some code from C# to C++ and am having a problem with one of the functions in one of the interfaces.

    The original function in the interface in C# is:

    void GetApplicationThreadCount(String applicationId, out Int32 totalthreads, out Int32 unfinishedThreads);

    and the C# implementation:

    public void GetApplicationThreadCount(String applicationId, out IntPtr totalThreads, out IntPtr unfinishedThreads)


    after reading for a while about the out keyword, I thought I should convert the interface to this:

    virtual void GetApplicationThreadCount(String^ applicationId, [System::Runtime::InteropServices::Out] %totalthreads, [System::Runtime::InteropServices::Out] %unfinishedThreads);

    and the c++ implementation to this:

    void GetApplicationThreadCount(String^ applicationId, [System::Runtime::InteropServices::Out] %totalThreads, [System::Runtime::InteropServices::Out] %unfinishedThreads)


    now I put all this together in a mixed project(the code I have converted along side the original code) so I could debug as I was wtiting it, and the C++ version appeared to work when called from C#, however, I am now converting that calling code to C++ and it does not work anymore.

    The calling code from C# is:

    GetApplicationThreadCount(application.ApplicationId, out totalThreads, out unfinishedThreads);

    and the calling code in C++:


    GetApplicationThreadCount(application->ApplicationId, totalThreads, unfinishedThreads);

    totalThreads and unfinishedThreads are of type IntPtr, but when I try this, the compiler keeps telling me that I havent implemented this function yet, Im not sure but think something must be wrong in the implementation,but I am at a loss as to how to fix it.

    I need the code to be callable from both C# and C++.

    Thanks in advance,

    Richard

  2. #2
    Join Date
    Jun 2010
    Location
    Germany
    Posts
    2,583

    Re: Problem implementing an interface

    This isn't meant to be part of a COM interface, is it? Then there's no need for the [Out] attribute. So this should do:

    Code:
    virtual void GetApplicationThreadCount(String^ applicationId, Int32 %totalthreads, Int32 %unfinishedThreads);
    The % already expresses what the out keyword in C# does.

    Also, I don't see any reason to use IntPtr in your post but maybe I missed something. Note that IntPtr and Int32 are only (more or less) equivalent in a 32-bit environment.
    I was thrown out of college for cheating on the metaphysics exam; I looked into the soul of the boy sitting next to me.

    This is a snakeskin jacket! And for me it's a symbol of my individuality, and my belief... in personal freedom.

  3. #3
    Join Date
    Aug 2009
    Location
    Finally back in Alaska
    Posts
    141

    Re: Problem implementing an interface

    No, this isnt for a com interface. I was just trying to make the code as exact to the C# code in c++ as I could since the C# code allready worked for the most part.

    I have the signature in the interface and the implementation exactly as shown below, however, the compiler still says I dont have it implemented. Am I supposed to have virtual in both the interface and the implementation? do I need to follow the implementation with the override keyword? I tried all this with and without those keywords, I copied and pasted the interface code into the implementation definition just in case I mistyped something that I am not seeing but Im still at a loss.


    Code:
    virtual void GetApplicationThreadCount(String^ applicationId, Int32 %totalthreads, Int32 %unfinishedThreads);
    by the way, this is the error Im getting:

    Error C3766: 'Alchemi::Manager::Storage::InMemoryManagerStorage' must provide an implementation for the interface method
    'void Alchemi::Core::Manager::Storage::IManagerStorage::GetApplicationThreadCount(System::String ^,int %,int %)' c:\programming\c++ version\working dir\mymanager\mymanager\MyManager.h 1302
    Last edited by AKRichard; April 1st, 2011 at 08:34 AM.

  4. #4
    Join Date
    Aug 2009
    Location
    Finally back in Alaska
    Posts
    141

    Re: Problem implementing an interface

    never mind, I just copied and pasted the definition from the interface to the implementation again and it worked, I must of screwed up the first time I did it.

    Thanks for the help,

    Richard

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Azure Activities Information Page

Windows Mobile Development Center


Click Here to Expand Forum to Full Width

This is a CodeGuru survey question.


Featured


HTML5 Development Center