Free File Function
You can open multiple files at once, as long as you
assign each file a different file number. You must
keep a track of the next available number. VB provides
the FreeFile() function, which returns an Integer
representing the next file number available for use
by the Open statement.
The optional rangenumber argument is a Variant that
specifies the range from which the next free file
number is to be returned.
Closing A File
When you are finished with the open file, you must
execute code that will close the file. Closing the
file releases the file buffer and returns the file
number to the unused pool. It also flushes the buffer
so that all new data for the file is saved.
The Close statement concludes input/output (I/O)
to a file opened using the Open statement.
The following code segment opens two sequential files-one
for reading and one for writing.
Dim intRFile As Integer, intWFile
intRFile = FreeFile
Open "read.txt" For Input As intRFile
intWFile = FreeFile
Open "write.txt" For Output As intWFile