CreateDbPointOverlay Method

Description

Creates an overlay which views Point data stored in a database.

Syntax

Visual Basic
Public Function CreateDbPointOverlay( _ ByVal pos As Integer, _ ByVal prj As String, _ ByVal rs As String, _ ByVal aclass As String, _ ByVal nfX As Integer, _ ByVal nfY As Integer, _ ByVal nfId As Integer, _ ByVal nfSr As Integer, _ ByVal nfZ As Integer, _ ByVal nfUnused As Integer, _ ByVal span As Double _ ) As Integer

Visual Basic

Public Function CreateDbPointOverlay( _
   ByVal pos As Integer, _
   ByVal prj As String, _
   ByVal rs As String, _
   ByVal aclass As String, _
   ByVal nfX As Integer, _
   ByVal nfY As Integer, _
   ByVal nfId As Integer, _
   ByVal nfSr As Integer, _
   ByVal nfZ As Integer, _
   ByVal nfUnused 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 coordinate reference system of the stored Point coordinates. This can be defined as:

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.

aclass

The class of Item to create: "Point" or "Text".

Text Items may be created by aliasing any string column in the named recordset to Text. Each Text item created will then get its text from the aliased column.

nfX

The index in the recordset columns argument of the x coordinate column. This column must exist. A value of -1 will make SIS generate the Item id-s automatically.

nfY

The index in the recordset columns argument of the y coordinate column. This column must exist. A value of -1 will make SIS generate the Item id-s automatically.

nfId

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

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.

nfZ

The index in the recordset columns argument of the z coordinate column. A value of -1 indicates that points are 2D, and the Z values will be set to zero.

nfUnused

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

span

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

Remarks

It may be necessary to call RefreshDataset after this command, to ensure that points are displayed.

Available: GEO D OD OM SISpy

Groups:

Example

sis.CreateDbPointOverlay (1, "*APrjNatGrid", "Planning", "Point", 1, 2, 3, -1, -1, 0, 2000000)

Creates an overlay at position 1 on the overlays list, in the given coordinate reference system, using recordset Planning, display as points, x index is 1, y index is 2 (positions of the columns containing coordinate information in the column argument used to define the recordset), ID index is 3, no spatial reference, within a span of 2 000 000m.