It is possible to use a FileShare value of FileShare.ReadWrite to open a file for reading, while it is already open in other programs (e.g. like Excel). e.g.:
using (FileStream fs = new FileStream(@"c:\abd\somefile.xlsx",
FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
// read file, etc.
}
Just wondering if this a good idea. e.g. in worst case, what will happen if the external program is writing to the file, and your code is trying to read it at the same time ?
I have noticed libraries like spreadsheet gear that can read files even when they are open in Excel - are they basically hoping that they will be able to read the whole file into memory before any part of it is changed ?
~$filename.xlsx) that is used to tell other users that you're currently editing the file. Excel doesn't actually read-lock the file, though, in order for other users to be able to copy the file and edit their copy of it.