CreateDbPointOverlay Method
Description
Creates an overlay which views Point data stored in a database.
Syntax
Visual Basic |
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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.