API interfacing with a LPBYTE from C#

[Dave A]

Hi, I have the following function that I need to call from C#.

HRESULT CamPreviewGetBG R16(HANDLE hCamera,LPBYTE pBuffer);

but I am stuggling with the LPBYTE pBuffer. I have decalred it as

[DllImport("mobi lecamapi.dll",E ntryPoint="CamP reviewGetBGR16" )]
public static extern int CamPreviewGetBG R16(uint hCamera, byte[] pBuffer);

and have called it via:

byte[] buffer = new byte[width * height * 2];
result = CamPreviewGetBG R16(cameraHandl e, buffer);

It is returning with a missing method exception. I think the 'byte[]
pBuffer' in the API definition needs to be a 'uint pBuffer' but then how do
I convert the 'byte[] buffer' in the calling code to be a uint? (I am a bit
of a novice at all of this Interop stuff)

Any suggestions are greatly appreaciated.

Thanks

Dave A

[Xedecimal]

RE: API interfacing with a LPBYTE from C#

Dug around a bit for lpbyte and C# and found some information on it...

System.Runtime. InteropServices .Marshal.CopyBy tesToManaged(In t32 source,
Byte[] destination, Int32 startIndex, Int32 length)

Not sure but it looks to be what will make you a managed lpbyte array, also
if you have too much trouble with this dll, there's avicap32.dll that I
always used to do webcam things with.

"Dave A" wrote:
[color=blue]
> Hi, I have the following function that I need to call from C#.
>
> HRESULT CamPreviewGetBG R16(HANDLE hCamera,LPBYTE pBuffer);
>
> but I am stuggling with the LPBYTE pBuffer. I have decalred it as
>
> [DllImport("mobi lecamapi.dll",E ntryPoint="CamP reviewGetBGR16" )]
> public static extern int CamPreviewGetBG R16(uint hCamera, byte[] pBuffer);
>
> and have called it via:
>
> byte[] buffer = new byte[width * height * 2];
> result = CamPreviewGetBG R16(cameraHandl e, buffer);
>
> It is returning with a missing method exception. I think the 'byte[]
> pBuffer' in the API definition needs to be a 'uint pBuffer' but then how do
> I convert the 'byte[] buffer' in the calling code to be a uint? (I am a bit
> of a novice at all of this Interop stuff)
>
> Any suggestions are greatly appreaciated.
>
> Thanks
>
> Dave A
>
>
>
>[/color]

[Dave A]

Re: API interfacing with a LPBYTE from C#

Thanks! That looks like the answer.

This is for the Pocket PC. I don't think avicap32.dll will work.

Regards
Dave

"Xedecimal" <Xedecimal@disc ussions.microso ft.com> wrote in message
news:1126A2DC-78EA-4A05-BE6D-42BA8E1EB385@mi crosoft.com...[color=blue]
> Dug around a bit for lpbyte and C# and found some information on it...
>
> System.Runtime. InteropServices .Marshal.CopyBy tesToManaged(In t32 source,
> Byte[] destination, Int32 startIndex, Int32 length)
>
> Not sure but it looks to be what will make you a managed lpbyte array,[/color]
also[color=blue]
> if you have too much trouble with this dll, there's avicap32.dll that I
> always used to do webcam things with.
>
> "Dave A" wrote:
>[color=green]
> > Hi, I have the following function that I need to call from C#.
> >
> > HRESULT CamPreviewGetBG R16(HANDLE hCamera,LPBYTE pBuffer);
> >
> > but I am stuggling with the LPBYTE pBuffer. I have decalred it as
> >
> > [DllImport("mobi lecamapi.dll",E ntryPoint="CamP reviewGetBGR16" )]
> > public static extern int CamPreviewGetBG R16(uint hCamera, byte[][/color][/color]
pBuffer);[color=blue][color=green]
> >
> > and have called it via:
> >
> > byte[] buffer = new byte[width * height * 2];
> > result = CamPreviewGetBG R16(cameraHandl e, buffer);
> >
> > It is returning with a missing method exception. I think the 'byte[]
> > pBuffer' in the API definition needs to be a 'uint pBuffer' but then how[/color][/color]
do[color=blue][color=green]
> > I convert the 'byte[] buffer' in the calling code to be a uint? (I am a[/color][/color]
bit[color=blue][color=green]
> > of a novice at all of this Interop stuff)
> >
> > Any suggestions are greatly appreaciated.
> >
> > Thanks
> >
> > Dave A
> >
> >
> >
> >[/color][/color]