Retrieving pictures from Canon camera using EDSDK 2.9

I been trying to retrieve images taken on the camera for a very long time now. I am able to take pictures with the SDK using:

err = EDSDK.EdsSendCommand(cameraDev, EDSDK.CameraCommand_TakePicture, 0);

I do this after opening a valid camera session. I have also added a

objectEventHandler and a stateEventHandler for the events that look like:

    public static uint stateEventHandler(uint inEvent, uint inParameter, IntPtr inContext)
    {
        switch (inEvent)
        {
            case EDSDK.StateEvent_JobStatusChanged:
                Debug.WriteLine(String.Format("There are objects waiting to be transferred.  Job status {0}", inParameter));
                break;

            case EDSDK.StateEvent_ShutDownTimerUpdate:
                if (inParameter != 0)
                    Debug.WriteLine(String.Format("shutdown timer update: {0}", inParameter));
                break;

            default:
                Debug.WriteLine(String.Format("StateEventHandler: event {0}, parameter {1}", inEvent, inParameter));
                break;
        }
        return 0;
    }

    public static uint objectEventHandler(uint inEvent, IntPtr inRef, IntPtr inContext)
    {
        switch (inEvent)
        {
            case EDSDK.ObjectEvent_VolumeInfoChanged:
                Debug.WriteLine("volume info changed");

                #region retrieve volume info

                EDSDK.EdsVolumeInfo volumeInfo;
                err = EDSDK.EdsGetVolumeInfo(inRef, out volumeInfo);
                if (err == EDSDK.EDS_ERR_OK)
                {
                    switch (volumeInfo.StorageType)
                    {
                        case (uint)EDSDK.EdsStorageType.Non:
                            Debug.WriteLine("No card inserted");
                            break;
                        default:
                        case (uint)EDSDK.EdsStorageType.CF:
                        case (uint)EDSDK.EdsStorageType.SD:
                            if (volumeInfo.Access == (uint)EDSDK.EdsAccess.ReadWrite)
                            {
                                Debug.WriteLine(String.Format("Label: {0}, Max Capacity: {1}, Free Space: {2}",
                                    volumeInfo.szVolumeLabel, volumeInfo.MaxCapacity, volumeInfo.FreeSpaceInBytes));

                                /*
                                err = EDSDK.EdsGetChildAtIndex(volumeInfo, 0, directoryList);
                                if (err != EDSDK.EDS_ERR_OK)
                                    throw new Exception(String.Format("EdsGetChildAtIndex: " + err.ToString()));
                                */
                            }
                            else
                                Debug.WriteLine(String.Format("Volume access rights: {0}", volumeInfo.Access));
                            break;
                    }
                }

                #endregion retrieve volume info

                break;

            case EDSDK.ObjectEvent_DirItemCreated:
                downloadImage(inContext);
                Debug.WriteLine("dir item created");
                break;

            default:
                Debug.WriteLine(String.Format("ObjectEventHandler: event {0}", inEvent));
                break;
        }
        return 0;
    }

I have tried multiple approaches (to retrieve this image) none of them seem to work. Some of the approaches are:

http://tech.groups.yahoo.com/group/CanonSDK/message/1575

[http://stackoverflow.com/questions/3762530/take-picture-and-directly-save-image-to-pc-using-edsdk-2-8]

[http://canonsdk.com/phpBB3/viewtopic.php?f=7&t=94&sid=7fcbe7ad6eadb399dbcb4b61a7333112]

The thing is all of them are just part of the code, when I try to put it in mine, it never works properly.Probably because I am no expert on memoryStreams, pointers an so. Most of the errors I get are when reading the streams and copying them to a local buffer, it says the stream is empty.

Does anybody have full sample code for ta开发者_如何学Cking a picture and downloading it to disk (or to memory), or the rigth approach that I need in order to complete this?

Thanks Fernando

the error in your code is:

downloadImage(inContext);

it should be

 downloadImage(inRef);

downloading the capture image into a harddisk as a file , you can check it out

void DownloadImage(IntPtr DirectoryRef)
{
    IntPtr stream = IntPtr.Zero;

    try
    {
        Error = EDSDK.EdsGetDirectoryItemInfo(DirectoryRef, out dirItemInfo);

        if (Error == OK)
        {
            Error = EDSDK.EdsCreateFileStream(dirItemInfo.szFileName,
            EDSDK.EdsFileCreateDisposition.CreateAlways, EDSDK.EdsAccess.ReadWrite, out stream);
        }

        if (Error == OK)
        {
            Error = EDSDK.EdsDownload(DirectoryRef, dirItemInfo.Size, stream);
        }

        if (Error == OK)
        {
            Error = EDSDK.EdsDownloadComplete(DirectoryRef);
        }
        else
        {
            Error = EDSDK.EdsDownloadCancel(DirectoryRef);
        }

        Error = EDSDK.EdsGetPointer(stream, out data);
        if (Error != OK)
                throw new Exception("Invalid Pointer Handler. Error Code:" + err.getErrorName(Error) + "(" + Error + ")" );

        Error = EDSDK.EdsGetLength(stream, out size);

        Bitmap retImage = null;
   }
   catch (Exception ex)
   {

   }

   EDSDK.EdsRelease(stream);
   EDSDK.EdsRelease(data);            
}