VB.NET Picture Box Image Pointer?

[ee0jmt]

Hi all.

Using VB.NET

I am using a Frame grabber SDK that passes picturebox.handle to a function in the framegrabber dll and the result is that a video frame is displayed in the picture box. That bits fine.

I now need to pass a pointer to that picturebox image to another sdk dll function. I thought that passing picturebox.handle.toint32 was the same as a pointer but I get the following error.

Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Could someone tell me how to pass a picturebox image pointer and also maybe someone could explain what a handle is.

All help appreciated!

[Plater]

You will probably have to mark that code as "unsafe" so that it does not safe guard the memory where the pointer is held.

[ee0jmt]

Hi again.

I have realised that I was trying to pass picturebox.handle.toint32 to the dll function. I changed it to:

dim p as intptr
p = picturebox.handle

and then pass p instead. I no longer get the error. However if I save the passed image using the sdk dll function and view it, it is not the image that was in the picturebox.

Is picturebox.handle a pointer to the memory that contains the image or does it need converting?

Could someone point me in the dirrection of some text that explains handles and pointers?

[Plater]

You could try checking in at the C/C++ or windows forum, since handles and pointers is more their realm then .NET