<DiskFile variable>.Unlock (Function)

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The unlock operation was not performed
Unlocking a file
Position in the file

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<DiskFile variable>.Unlock (Function)

In french: <Variable FichierDisque>.Débloque

Entirely or partially unlocks an external file. The file was locked by <DiskFile variable>.Lock.

Attention Unlocking can only be performed if the part to be unlocked corresponds to the blocked part.

Example

// Open an external file
MyTextFile is DiskFile
ResUnlock is boolean
IF MyTextFile.Open("C:\MyDirectories\File.txt", foReadWrite) = True THEN
	// Lock the file
	ResLock = MyTextFile.fLock()
	...
	// Unlock the external file
	ResUnlock = MyTextFile.Unlock()
END

Syntax

<Result> = <File used>.Unlock([<First byte to unlock> [, <Number of bytes to unlock>]])

<Result>: Boolean

True if the unlock operation was performed,
False otherwise.

<File used>: DiskFile variable

Name of the DiskFile variable initialized with <DiskFile variable>.Open or <DiskFile variable>.Create.

<First byte to unlock>: Optional integer

Position of the first byte (character) to unlock (0 corresponds to the first byte of the file).

<Number of bytes to unlock>: Optional integer

Number of bytes (characters) to unlock.

Remarks

The unlock operation was not performed

<DiskFile variable>.Unlock returns False if the unlock operation was not performed. The unlock operation can be performed if:

the external file is opened.
the file identifier is valid.
the file or the bytes to unlock are identical to the locked ones. For example, if only a file section was locked, this same section must be unlocked. If the file was entirely locked, you cannot unlock a section of the file.
the file or the bytes to unlock have been locked by the same application and from the same computer.

Unlocking a file

The file is entirely unlocked if <First byte to unlock> and <Number of bytes to unlock> are not specified.
The file is unlocked from the first specified byte (<First byte to unlock>) to the end of file if <Number of bytes to unlock> is not specified.
A blocked (or partially blocked) file will be automatically unblocked when it is closed.

Position in the file

When opening a file, the current position corresponds to:

the first file byte (by default),
the last byte of the file if the file is opened in "addition" mode (foAdd constant).

This position can be modified by <DiskFile variable>.Seek.

The current position does not change when <DiskFile variable>.Unlock is executed.

Business / UI classification: Business Logic

Component: wd300std.dll