'_RemotableHandle' type error when trying to use ActiveX in Qt

Taytoo

We have an internal ActiveX COM control (written in C++) that I'm trying to use in the new Qt app. Note that we've successfully used it in regular C++ and also in WinForms (.NET) windows applications and it works.

I used dumpcpp to generate .h/.cpp files, which worked without any issue but the code won't compile because of missing _RemotableHandle definition. I do see a forward declaration for it though, actually its in the header file twice (but only declaration):

struct _RemotableHandle;

Spent some time on google and it looks like this is a COM type used for HWND. How do I fix this error? I don't see anyone else having this issue, maybe I'm doing something wrong?

Gao.xiangyang

"I'm using dumpcpp to generate .h/.cpp files for mstscax.dll, but in the .h file, only the declaration of the struct _RemotableHandle is present. Have you found a solution for this?"

Gao.xiangyang

@Gao-xiangyang

通过查看
echo '#import "mstscax.dll" named_guids' > import.cpp
cl.exe /c /nologo .\import.cpp
midl.exe .\mstscax.idl /header mstscax.h /iid mstscax_i.c
dumpcpp .\mstscax.tlb

By comparing the mstscax.idl file with the .h file generated by dumpcpp, it was found that dumpcpp has issues with handling typedefs, for example:

in .idl file

 typedef [public]
    _RemotableHandle* wireHWND;

    typedef union tag__MIDL_IWinTypes_0009 {   
      long hInproc;
      long hRemote;
    } __MIDL_IWinTypes_0009;

    typedef struct tag_RemotableHandle {       
      long fContext;
      __MIDL_IWinTypes_0009 u;
    } _RemotableHandle;

dumpcpp.exe output .h file

    //  The struct tag_RemotableHandle is declared twice.
    struct tag_RemotableHandle; 
    struct tag_RemotableHandle;