MapWinGIS:Shapefile SelectShapes

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SelectShapes

Gets all shapes in the shapefile that lie within the specified bounding box.
See also Extents and SelectMode


VB.NET Usage

Function SelectShapes(BoundBox As MapWinGIS.Extents, Optional Tolerance As Double, Optional SelectMode As MapWinGIS.SelectMode, Optional ByRef result As Object) As Boolean

            Parameters

BoundBox

The bounding box used to determine which shapes in the shapefile to return as selected. The bounds must be in projected map units.
Tolerance Optional. This is used to extend the boundaries of the specified bounding box to allow shapes not otherwise selected to be considered within the bounding box. The default value is 0.0.
SelectMode Optional. Determines whether shapes must be completely enclosed by the bounding box or just intersected by the bounding box to be considered selected. The default is MapWinGIS.SelectMode.INTERSECTION.
result Optional, reference parameter. An array of shape indexes of shapes in the shapefile that have been selected.
ReturnValue A boolean value representing whether any shapes in the shapefile have been selected or not.

Sample Code

    Private Sub ShapefileSelectShapes()
        Dim sf As New MapWinGIS.Shapefile()
        Dim extents As New MapWinGIS.Extents()
        Dim top As Integer, bottom As Integer, left As Integer, right As Integer, result() As Integer
        Dim success As Boolean
        'Set the value of the bounds to use for the bounding box in projected map coordinates
        top = 300
        bottom = 100
        left = 100
        right = 300
        'Set the extents using the bounding box coordinates
        extents.SetBounds(left, bottom, 0, right, top, 0)
        'Get the shapes that are completely contained in the bounding box in the result array
        success = sf.SelectShapes(extents, 0.0, MapWinGIS.SelectMode.INCLUSION, result)
    End Sub
  

VB 6 Usage
Function SelectShapes(BoundBox As Extents, Optional Tolerance As Double, Optional SelectMode As SelectMode, Optional ByRef result As Object) As Boolean
            Parameters

BoundBox

The bounding box used to determine which shapes in the shapefile to return as selected. The bounds must be in projected map units.
Tolerance Optional. This is used to extend the boundaries of the specified bounding box to allow shapes not otherwise selected to be considered within the bounding box. The default value is 0.0.
SelectMode Optional. Determines whether shapes must be completely enclosed by the bounding box or just intersected by the bounding box to be considered selected. The default is MapWinGIS.SelectMode.INTERSECTION.
result Optional, reference parameter. An array of shape indexes of shapes in the shapefile that have been selected.
ReturnValue A boolean value representing whether any shapes in the shapefile have been selected or not.

Sample Code

    Private Sub ShapefileSelectShapes()
        Dim sf As New MapWinGIS.Shapefile
        Dim extents As New MapWinGIS.extents
        Dim top As Long, bottom As Long, left As Long, right As Long, result() As Long
        Dim success As Boolean
        'Set the value of the bounds to use for the bounding box in projected map coordinates
        top = 300
        bottom = 100
        left = 100
        right = 300
        'Set the extents using the bounding box coordinates
        extents.SetBounds left, bottom, 0, right, top, 0
        'Get the shapes that are completely contained in the bounding box in the result array
        success = sf.SelectShapes(extents, 0, MapWinGIS.SelectMode.INCLUSION, result)
    End Sub

Retrieved from "http://mapwindow.org/wiki/index.php/MapWinGIS:Shapefile_SelectShapes"

This page has been accessed 6,864 times. This page was last modified on 9 November 2005, at 18:24.