c# - problem with download picture from canon camera to pc -

I have a EOS Canon Camera for PC
I have an application that I can remove from the picture , And I can download the image of PC,

But when I remove the SD card from the camera, I can not download the image from buffer to PC

// Register objceteventcallback

  err = EDSDK.EdsSetObjectEventHandler (obj.camdevice, EDSDK.ObjectEvent_All, objectEventHandler, New IntPtr (0)); If (error! = EDSDK.EDS_ERR_OK) debug it. WrightLine ("Error in Registering the Object Event Handler"); Public UIT Object Event Handler (UIT Inant, Interrupt Enerf, Interrupt Incontext) {Switch (Invert) {Case EDSDK. Object AITIT: getCapturedItem (inRef); Debug Virline ("Made Dior Item"); break; Case EDSDK.ObjectEvent_DirItemRequestTransfer: this.getCapturedItem (inRef); Debug. WrightLine ("file transfer request event"); break; Default: debug.lightline (string.format ("object extendaller: event {0}", event)); break; } Return 0; }  

Anyone can help me, why does not this event call,

or how do I download the image from PC to buffer, on my camera

You probably ran into the same problem as I did with the SD card Yesterday did: The camera tries to store the image for later downloads, does not find any memory card to store it and immediately discard the image gives.

To bring your callback to the fire, you need to save the camera to the PC (KEdsSaveTo_Host) at some point during your camera initialization routine. In C ++, it works like this:

  EdsInt32 saveTarget = kEdsSaveTo_Host; Err = EdsSetPropertyData (_camera, kEdsPropID_SaveTo, 0, 4, and saveTarget);  

You need to create an IntPtr for it at least, this is what Dimitri Prozhorovski (inspired by a certain Akkadanova )