All Cadcorp SIS API Methods

CreateDbBlobOverlay Method

Description

Creates an overlay which views Blobs stored in a database.

Syntax

Public Function CreateDbBlobOverlay( _
   ByVal pos As Integer, _
   ByVal prj As String, _
   ByVal rs As String, _
   ByVal fmt As Integer, _
   ByVal nfBlob As Integer, _
   ByVal nfId As Integer, _
   ByVal nfVer As Integer, _
   ByVal nfSr As Integer, _
   ByVal nfSlMin As Integer, _
   ByVal nfSlMax As Integer, _
   ByVal span As Double _
) As Integer

Parameters

pos

The position in the overlays list at which to insert the overlay. If this argument specifies a position in the existing overlays then the new overlay will not replace the existing overlay at the given position, but will shuffle any other overlays down the list.

 

prj

The named projection of the stored Item Blobs.

• OGC URNs (eg 'urn:ogc:def:crs:OGC:1.3:CRS84')
• EPSG URNs (eg 'urn:ogc:def:crs:EPSG::27700')
• EPSG code strings (eg 'EPSG:27700')
• EPSG URLs (eg 'http://www.example.com/epsg#27700' or 'http://www.example.com/epsg.xml#27700')
• EPSG codes as a simple string (eg '27700')

If blank, this will default to the current 'axes' CRS.

 

rs

A named recordset previously created using DefineRecordset.

 

fmt

The format of the Item Blob.

SIS_BLOB_OGIS_WKB	1 = OGC Well-Known-Binary format
SIS_BLOB_OGIS_WKT	2 = OGC Well-Known-Text format
SIS_BLOB_OGIS_GML	3 = OGC Geographic Markup Language
SIS_BLOB_ESRI_SHP	4 = ESRI Shape (*.shp)
SIS_BLOB_SIS_BIN_ITEM	5 = Binary item
SIS_BLOB_GEOJSON	6 = Geographic Objects for JSON format

 

nfBlob

The index in the recordset columns argument of the Item Blob string column. This column must exist.

 

nfId

The index in the recordset columns argument of the Item id column. A value of -1 will make Cadcorp SIS generate the Item id-s automatically.

 

nfVer

The index in the recordset columns argument of the Item version column. A value of -1 indicates that no version information is being supplied.

nfSr

The index in the recordset columns argument of the Item spatial reference column. A value of -1 indicates that no spatial reference is being supplied.

 

nfSlMin

This parameter is currently ignored, please use -1 for future compatibility.

The index in the recordset columns argument of the Item minimum scale threshold column. A value of -1 indicates that no minimum scale threshold is being supplied.

nfSlMax

This parameter is currently ignored, please use -1 for future compatibility.

The index in the recordset columns argument of the Item maximum scale threshold column. A value of -1 indicates that no maximum scale threshold is being supplied.

span

The span used in the spatial reference (see GetSpatialReference).

Remarks

Example