Interface method calling convention

[Builder]

Hi,

I imported following COM interface

DECLARE_INTERFACE(IAxMediaCB)
{

STDMETHOD(BufferCB)
(
LONGLONG theStartTime,
BYTE * theDstBuffer,
long theSize
) PURE;
};


to managed code:

public interface IAxMediaCB
{
int BufferCB(long theStartTime, IntPtr theDstBuffer, int
theSize);
}

Is there any way to declare in .NET that interface method BufferCB has
a __cdecl calling convention? I know there is
UnmanagedFunctionPointerAttribute, but this can be only applied on
the delegate. I need somethig similar, but destination should be a
method. Is there any way to do it?

 

[Pavel Minaev]

Hi,

I imported following COM interface

DECLARE_INTERFACE(IAxMediaCB)
{

  STDMETHOD(BufferCB)
    (
    LONGLONG  theStartTime,
    BYTE * theDstBuffer,
    long  theSize
    ) PURE;

};

to managed code:

    public interface IAxMediaCB
    {
        int BufferCB(long theStartTime, IntPtr theDstBuffer, int
theSize);
    }

Is there any way to declare in .NET that interface method BufferCB has
a __cdecl calling convention?

Actually, given your C declaration, the method is not cdecl; it's
stdcall. Which means that .NET COM interop should just work. You will
still need MethodImplAttribute on method declarations, though - import
some random COM component into your .NET application, and look at the
generated assembly in ildasm to see what it would look like.

 

[Mattias Sjögren]

You will
still need MethodImplAttribute on method declarations, though - import
some random COM component into your .NET application, and look at the
generated assembly in ildasm to see what it would look like.

That's not necessary, but he will need to add the ComImport, Guid and
InterfaceType attributes to the interface itself.


Mattias