VB6 Lock statement syntax: - Lock [#]filenumber[, recordrange] Controls access to all or part of an open file. The Lock statement syntax has these parts:
| Part | Description |
|---|---|
| filenumber | Required. Any valid file number. |
| recordrange | Optional. Range of records to lock. Can be: record, start To end, or omitted for entire file. |
Remarks
- Lock and Unlock are used in environments where multiple processes might need access to the same file.
- Lock and Unlock statements are always used in pairs.
- The Lock statement locks all or part of a file opened using the Open statement.
- The first record or byte in a file is at position 1, the second at position 2, and so on.
- If you specify just one record number, only that record is locked.
- If you specify a range, all records in that range are locked.
- For files opened in Binary, Input, or Output mode, Lock always locks the entire file, regardless of the recordrange argument.
- For files opened in Random mode, Lock locks the specified record or range of records.
- Locked portions of a file can't be accessed by other processes until unlocked with Unlock.
- Use Unlock to remove the lock from a portion of a file.
Examples
Lock #1
Lock #1, 5
Lock #1, 10 To 20
Lock fileNum, recordNum