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Call .NET C# dll from QT ?



  • Hi ,
    I'm new in C++ and QT and I need some help.
    I have built a com object (not something visual) with some methods and the task is to call my .NET C# dll from inside QT (a console application or even a Windows Application).
    I read the documentation and tried unsuccessfully to make that call happen.

    I read the below
    http://doc.qt.digia.com/4.6/qaxbase.html#control-prop
    https://qt-project.org/doc/qt-4.7/activeqt-dotnet.html

    but without success.

    Can anyone has a small snippet of code on how to do this in QT ?
    Is QT supports that ?

    I tried to use this
    QAxObject object("C:/Myfolder/MyCOM.dll")
    but I got an unresolved something
    I tried this
    QLibrary lib( "C:\Myfolder\MyCOM.dll" );
    lib.load();
    but it was not loaded.
    I ran out of ideas .

    Appreciate any help you could give me.
    thank you in advance



  • I have tried this
    QLibrary mylib("C:\Myfolder\MyCOM.dll");
    bool okLoad = mylib.load();
    bool loaded = mylib.isLoaded();

    and both bool return true
    So, that means that the dll is loaded ?
    And Now how can I call a method from the Com Object ?



  • You need to resolve the functions you would like to call in the dll. The "QLibrary documentation":http://qt-project.org/doc/qt-5/QLibrary.html shows an example.

    Create a typedef for the function prototype, then resolve the function by name.



  • C# DLL cannot directly called like C++ DLL's. So QLibrary cannot be used.

    You can use QAxObject, but your C# DLL need to export COM objects (Interop) which is not enabled by default during compilation.



  • I apologize, you are correct. QLibrary is only for C.

    There is a good example on the QAxBase docs "here":https://qt-project.org/doc/qt-4.7/qaxbase.html, although I have only used QAxObject to populate Microsoft excel documents


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