Name
Unlock Procedure
Class
Microsoft.VisualBasic.FileSystem
Syntax
Unlock(filenumber[, record
) Unlock(filenumber[,fromrecord[, torecord]]
)
-
filenumber
Use: Required
Data Type: Integer
Any valid file number
-
record
Use: Required
Data Type: Long
The record or byte number at which to commence the lock
-
fromrecord
Use: Required
Data Type: Long
The first record or byte number to lock
-
torecord
Use: Required
Data Type: Long
The last record or byte number to lock
Description
Use the Unlock
procedure in situations where
more than one part of your program may need read and write access to
the same data file. The Unlock
procedure removes
a lock that the Lock
procedure placed on a
section of the file or the whole file.
Rules at a Glance
Use the
Unlock
procedure only with thefilenumber
parameter to unlock the whole file.The
Unlock
procedure unlocks an entire file opened in Input or Output (sequential) mode, regardless of therecord
,fromrecord
, ortorecord
arguments.Records and bytes in a file are always numbered sequentially from 1 up.
To unlock a particular record, specify its record number as
record
, and only that record will be unlocked.To unlock a range of bytes (in a binary file) or of records (in a random file), indicate the starting position as
fromrecord
and the ending position astorecord
.
Programming Tips and Gotchas
You must take care to remove all file locks using the
Unlock
procedure before either closing a file or ending the application; otherwise, you can leave the file in an unstable ...
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