Occasional JPEG corruption with edtFTPNet Free version

Question

I am using edtFTPNet Free version 2.2.2 with VB.NET 2010. My program needs to upload small jpeg files (about 50KB) via FTP to my website. It does this quite frequently; sometimes 1 file every minute. A small javascript file is also transferred with every image. About 1 image in 10 suffers some corruption like this:

[ img ]

Please ignore the noise bars! It's the light brown coloured area at the bottom of the image I am referring to. Sometimes reloading the image from the server clears the corruption, but more often it does not. On many (but not all) occasions, the corruption disappears after several more images have been transferred, almost as if some data has been left in a buffer which is eventually transferred after several other FTP transactions have been completed. Any suggestions on debugging this problem?

Thanks,

Paul.

Answer 1

Hans - thank you for your support. I'm having trouble creating a test setup for you to try. I may have reduced (or even eliminated) the problem by changing the TransferBufferSize to 4096. I just transferred about 30 images and all were perfect. I think I will leave this problem for a while and concentrate on some other areas of my program. I will post again if I make any further progress.

Thanks again :D

Answer 2

You're welcome, though I don't believe I helped you very much. I'm still very curious, so I hope we get to the end of this tale at some point.

- Hans (EnterpriseDT)

Answer 3

Hans - do you know where I can find an example of doing an FTP transfer from a VB.NET MemoryStream rather than from a file? The UploadFile command is obviously looking only for a string containing a filename. Just an idea I'm working on ... changing the TransferBuffer size has not eliminated my problem.

Thanks,

Paul.

EDIT: Sorry - I think I've just found it! UploadStream instead of UploadFile :oops: