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DbServer.BLOBExport Method (Usual, FileSpec, Long)

X#
Copy the contents of a BLOB, identified by its memo field number, to a file.

Namespace:  XSharp.VO.SDK
Assembly:  XSharp.VORDDClasses (in XSharp.VORDDClasses.dll) Version: 2.21
Syntax
Copy
 VIRTUAL METHOD BLOBExport(
	uField AS USUAL,
	oFSTarget AS FileSpec,
	 kMode AS LONG
) AS LOGIC
Request Example View Source

Parameters

uField
Type: Usual
The name, number, or symbol representing the position of the field in the database file structure.
oFSTarget
Type: FileSpec
A string or filespec object that specifies the name of the target file where the BLOB data will be written, including an optional drive, directory, and extension. See SetDefault() and SetPath() for file searching and creation rules. No default extension is assumed. If oFSTarget does not exist, it is created. If it exists, this method attempts to open the file in exclusive mode and, if successful, the file is written to without warning or error. If access is denied because, for example, another process is using the file, NetErr() is set to TRUE and the data server's Status property is set.
kMode
Type: Long
A constant defining the copy mode, as shown in the table below:
ConstantDescription
BLOB_EXPORT_APPEND Appends to the file
BLOB_EXPORT_OVERWRITE Overwrites the file—this is the default

Return Value

Type: Logic
TRUE if successful; otherwise, FALSE.
Examples
This example exports the contents of a field that stores a picture to a .GIF file, so that the file can be programmatically displayed:
X#
Copy
 1FUNCTION ShowPix()
 2LOCAL cPixFile := "picture.gif" AS STRING
 3LOCAL nPos
 4LOCAL oDBCust AS DBServer
 5// Customer database with a picture of each     // customer stored in a field called Pix
 6oDBCust := Customer{}
 7nPos := oDBCust:FieldPos("Pix")
 8// Export the BLOB file's data
 9// for the current Pix field
10IF !oDBCust:BLOBExport(nPos, cPixFile, ;
11BLOB_EXPORT_OVERWRITE)
12Alert("Export of picture " + cPixFile + " failed!")
13ELSE
14// Code for displaying picture would go here
15ENDIF
See Also