Question

Is there a way to find if a file is already open or not?

Answer 1

protected virtual bool IsFileinUse(FileInfo file)
{
     FileStream stream = null;

     try
     {
         stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None);
     }
     catch (IOException)
     {
         //the file is unavailable because it is:
         //still being written to
         //or being processed by another thread
         //or does not exist (has already been processed)
         return true;
     }
     finally
     {
         if (stream != null)
         stream.Close();
     }
     return false; 
}