Determining File Size using API

i would like to know if there is an API function that i could use so i could be able to know the size of all files on a target path. actually i would like to mimic how windows computes for the size of a folder or files when you right click on it and chooses the property menu. im creating a program that browse through a drive and folders and copies all files from that drive, which includes nested directories. the problem is that i couldn't use a progress bar since i couldn't compute for FILE SIZE beforehand.

In VB FileLen("myfile") returns the length in bytes of a file.

Otherwise you have to use an api which employs the FILEINFO structure ( UDT )to return information.

Try this link http://www.andreavb.f2s.com/tip030001.html

Its a sample. Hope that can get u going :)