User Tools

Site Tools


api:dk11:net:tatukgis.ndk.tgis_layervector.cursorfindfirst_integer_boolean_tgis_extent_string_tgis_shape_string_boolean

Table of Contents

TGIS_LayerVector.cursorFindFirst method

DK11 for .NET | TatukGIS.NDK.TGIS_LayerVector.cursorFindFirst | Constructors | Fields | Methods | Properties | Events

Find first occurrence of an item which meets extent and query. Will use RTree if available.

Available also on: Delphi | Java.

Syntax

// C#
protected TGIS_Shape cursorFindFirst(
  int _cursor,
  bool _viewerCS,
  TGIS_Extent _extent,
  string _query,
  TGIS_Shape _shape,
  string _de9im,
  bool _skipDeleted
);
' VisualBasic
Protected Function cursorFindFirst(
  ByVal _cursor As Integer,
  ByVal _viewerCS As Boolean,
  ByVal _extent As TGIS_Extent,
  ByVal _query As String,
  ByVal _shape As TGIS_Shape,
  ByVal _de9im As String,
  ByVal _skipDeleted As Boolean
) As TGIS_Shape
// Oxygene
protected
  function cursorFindFirst(
    _cursor : Integer;
    _viewerCS : Boolean;
    _extent : TGIS_Extent;
    _query : String;
    _shape : TGIS_Shape;
    _de9im : String;
    _skipDeleted : Boolean
  ) : TGIS_Shape; virtual;

Parameters

Name Type Description
_cursor int
Integer
cursor identifier (see TGIS_LayerVector.cursorOpen)
_viewerCS bool
Boolean
if True an the layer has been attached to the Viewer then expected _extent units are in a Viewer coordinate space; otherwise expected _extent units are in a Layer coordinate space
_extent TGIS_Extent extent of item to be found
_query string
String
query which must be matched by item; closely mimics SQL WHERE clause; for examples you can use 'AGE >= 18'; empty (default) means that no all items will match.
_shape TGIS_Shape if not nil, then only shapes matched _de9im matrix with _shape will be found
_de9im string
String
DE-9IM matrix of comparison
_skipDeleted bool
Boolean
set a skip deleted treatment; by default deleted items will be ignored

Result

Type Description
TGIS_Shape Shape itself or nil.

Remarks

Use this method to find to the first shape in the layer matching given criteria. Using _query param we can narrow the result of the shape searching down to the minimum. This should speed up our process of locating a desirable shape.

2017/09/04 11:27