GetBlob Method

Description

Gets a Blob string of the current open Item, within a Coordinate Reference System.

Syntax

Public Function GetBlob( _
   ByVal projection As String, _
   ByVal fmt As Integer, _
   ByVal precision As Integer _
) As String

Parameters

projection

The named Coordinate Reference System of the returned Blob string.

 

fmt

The format of the stored Item Blob.

SIS_BLOB_SIS_V6_ASCII	0 = Cadcorp SIS format
SIS_BLOB_OGIS_WKT	2 = OGC Well-Known-Text format
SIS_BLOB_OGIS_GML	3 = OGC Geographic Markup Language
SIS_BLOB_GEOJSON	6 = Geographic Objects for JSON format

 

precision

This parameter is ignored and will always return 64-bit precision.

Return Type

A string describing the current open Item in the chosen format. SIS format strings are encoded and can only be interpreted by SIS.

Remarks

There is no limit on the length of Blob strings generated by SIS. There are however limits elsewhere: GisLink can only handle strings of a few Kb (this does not apply to the SIS Control); SIS datasets which read Blobs from data sources can use a fixed size communication buffer (use the Cadcorp OGC SQL92 Database Maximum Blob size, and Cadcorp View Geometry Maximum Blob size properties to change the size of the communication buffer).

Available: GEO ME MD OD SISpy

Groups:

• Database Methods
• Blob Methods

Example

sis.GetBlob ( "*APrjNatGrid", 0, 0 )

Returns the Blob string of the current item within the National Grid coordinate reference system.

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