managed C# to unmanaged DLL void*

[Mr.Tickle]

Hi,

I have a C function in a DLL that takes a void* that is passing back some
other type, what is the general way to do this with object rather than
declaring the actual type that its returning.


ATM I am using the function that has the following signiture


long someFn(long l, void* data);

I am calling it in C# as follows...

[DllImport("some Dll.dll", EntryPoint="som eFn"]
public static extern int someFn(int l, ref double);

double d = 0.0;

int l = someFn(10, ref d);

Is there a way I can call it with the following type reference pased in?

object obj;

someFn(10, ref obj);

[Willy Denoyette [MVP]]

Re: managed C# to unmanaged DLL void*

What makes you think the C function could return a pointer to an .NET object type?

Willy.


"Mr.Tickle" <MrTickle@mrmen .com> wrote in message news:e4RGWWPgDH A.696@TK2MSFTNG P09.phx.gbl...[color=blue]
> Hi,
>
> I have a C function in a DLL that takes a void* that is passing back some
> other type, what is the general way to do this with object rather than
> declaring the actual type that its returning.
>
>
> ATM I am using the function that has the following signiture
>
>
> long someFn(long l, void* data);
>
> I am calling it in C# as follows...
>
> [DllImport("some Dll.dll", EntryPoint="som eFn"]
> public static extern int someFn(int l, ref double);
>
> double d = 0.0;
>
> int l = someFn(10, ref d);
>
> Is there a way I can call it with the following type reference pased in?
>
> object obj;
>
> someFn(10, ref obj);
>
>
>[/color]

[Mr.Tickle]

Re: managed C# to unmanaged DLL void*

Just wanted a generic way of coding a void* instead of having to DllImport
them to every type I need.


"Willy Denoyette [MVP]" <willy.denoyett e@pandora.be> wrote in message
news:#SXFnaPgDH A.128@tk2msftng p13.phx.gbl...[color=blue]
> What makes you think the C function could return a pointer to an .NET[/color]
object type?[color=blue]
>
> Willy.
>
>
> "Mr.Tickle" <MrTickle@mrmen .com> wrote in message[/color]
news:e4RGWWPgDH A.696@TK2MSFTNG P09.phx.gbl...[color=blue][color=green]
> > Hi,
> >
> > I have a C function in a DLL that takes a void* that is passing back[/color][/color]
some[color=blue][color=green]
> > other type, what is the general way to do this with object rather than
> > declaring the actual type that its returning.
> >
> >
> > ATM I am using the function that has the following signiture
> >
> >
> > long someFn(long l, void* data);
> >
> > I am calling it in C# as follows...
> >
> > [DllImport("some Dll.dll", EntryPoint="som eFn"]
> > public static extern int someFn(int l, ref double);
> >
> > double d = 0.0;
> >
> > int l = someFn(10, ref d);
> >
> > Is there a way I can call it with the following type reference pased in?
> >
> > object obj;
> >
> > someFn(10, ref obj);
> >
> >
> >[/color]
>
>[/color]

[Mr.Tickle]

Re: managed C# to unmanaged DLL void*

Well I have it as...

[DllImport("some Dll.dll", EntryPoint="som eFn")]
public static extern int someFn(int l, [MarshalAs(Unman agedType.AsAny)]ref
object);

[DllImport("some Dll.dll", EntryPoint="som eFn")]
public static extern int someFn(int l, ref double);


But I dont want to have X number of DllImport lines overloaded for every
type I have to pass and get back. There has got to be an easier less
verbose way surely.



"Mr.Tickle" <MrTickle@mrmen .com> wrote in message
news:uzY6lBSgDH A.2364@TK2MSFTN GP09.phx.gbl...[color=blue]
> Just wanted a generic way of coding a void* instead of having to DllImport
> them to every type I need.
>
>
> "Willy Denoyette [MVP]" <willy.denoyett e@pandora.be> wrote in message
> news:#SXFnaPgDH A.128@tk2msftng p13.phx.gbl...[color=green]
> > What makes you think the C function could return a pointer to an .NET[/color]
> object type?[color=green]
> >
> > Willy.
> >
> >
> > "Mr.Tickle" <MrTickle@mrmen .com> wrote in message[/color]
> news:e4RGWWPgDH A.696@TK2MSFTNG P09.phx.gbl...[color=green][color=darkred]
> > > Hi,
> > >
> > > I have a C function in a DLL that takes a void* that is passing[/color][/color][/color]
back[color=blue]
> some[color=green][color=darkred]
> > > other type, what is the general way to do this with object rather than
> > > declaring the actual type that its returning.
> > >
> > >
> > > ATM I am using the function that has the following signiture
> > >
> > >
> > > long someFn(long l, void* data);
> > >
> > > I am calling it in C# as follows...
> > >
> > > [DllImport("some Dll.dll", EntryPoint="som eFn"]
> > > public static extern int someFn(int l, ref double);
> > >
> > > double d = 0.0;
> > >
> > > int l = someFn(10, ref d);
> > >
> > > Is there a way I can call it with the following type reference pased[/color][/color][/color]
in?[color=blue][color=green][color=darkred]
> > >
> > > object obj;
> > >
> > > someFn(10, ref obj);
> > >
> > >
> > >[/color]
> >
> >[/color]
>
>[/color]

[Mattias Sjögren]

Re: managed C# to unmanaged DLL void*

[color=blue]
>But I dont want to have X number of DllImport lines overloaded for every
>type I have to pass and get back.[/color]

How many overloads are we talking about?

[color=blue]
>There has got to be an easier less verbose way surely.[/color]

If you don't care about type safety, you could declare the method as
unsafe and actually type the parameter as void*.



Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org

http://www.msjogren.net/dotnet/

Please reply only to the newsgroup.

[Mr.Tickle]

Re: managed C# to unmanaged DLL void*

I dont know how many yet but quite a few as I am wrapping a huge amount of
DLL functions.

"Mattias Sjögren" <mattias.dont.w ant.spam@mvps.o rg> wrote in message
news:uR26u8TgDH A.3700@TK2MSFTN GP11.phx.gbl...[color=blue]
>[color=green]
> >But I dont want to have X number of DllImport lines overloaded for every
> >type I have to pass and get back.[/color]
>
> How many overloads are we talking about?
>
>[color=green]
> >There has got to be an easier less verbose way surely.[/color]
>
> If you don't care about type safety, you could declare the method as
> unsafe and actually type the parameter as void*.
>
>
>
> Mattias
>
> --
> Mattias Sjögren [MVP] mattias @ mvps.org
> http://www.msjogren.net/dotnet/
> Please reply only to the newsgroup.[/color]

[Mr.Tickle]

Re: managed C# to unmanaged DLL void*

How come [MarshalAs(Unman agedType.AsAny)] on the ref object parameter cant
resolve the type at runtime for every known type where possible?

I have one marshalled .AsAny but what purpose will that serve if I have to
overload them with the types as it seems I have to do.


"Mattias Sjögren" <mattias.dont.w ant.spam@mvps.o rg> wrote in message
news:uR26u8TgDH A.3700@TK2MSFTN GP11.phx.gbl...[color=blue]
>[color=green]
> >But I dont want to have X number of DllImport lines overloaded for every
> >type I have to pass and get back.[/color]
>
> How many overloads are we talking about?
>
>[color=green]
> >There has got to be an easier less verbose way surely.[/color]
>
> If you don't care about type safety, you could declare the method as
> unsafe and actually type the parameter as void*.
>
>
>
> Mattias
>
> --
> Mattias Sjögren [MVP] mattias @ mvps.org
> http://www.msjogren.net/dotnet/
> Please reply only to the newsgroup.[/color]