Table of Contents
TGIS_LayerVector.Locate(TGIS_Point, double) method
DK for .NET | TatukGIS.NDK.TGIS_LayerVector.Locate | Overloads | Constructors | Fields | Methods | Properties | Events
Locates the nearest shape to a reference point within the specified tolerance distance.
Syntax
// C# public virtual TGIS_Shape Locate( TGIS_Point _ptg, double _prec );
' VisualBasic Public Overridable Function Locate( ByVal _ptg As TGIS_Point, ByVal _prec As Double ) As TGIS_Shape
// Oxygene public function Locate( _ptg : TGIS_Point; _prec : Double ) : TGIS_Shape; virtual;
Parameters
| Name | Type | Description |
|---|---|---|
| _ptg | TGIS_Point | Reference point used for the search. The coordinate space depends on the caller context and layer/viewer usage. |
| _prec | double Double | Maximum search distance. Shapes farther than this tolerance are not returned. |
Result
| Type | Description |
|---|---|
| TGIS_Shape | The nearest matching shape, or nil if no shape is found within the specified tolerance. |
Remarks
PURPOSE: Supports interactive hit testing for vector features such as points, arcs/lines, and polygons.
BEHAVIOR: Searches candidate shapes near _ptg and returns the closest match within _prec. The search can use the layer's spatial index when available for faster lookup.
CONSTRAINTS: Distance is evaluated in the coordinate space supplied to the method. Results depend on the layer's current visibility and filtering rules.
If locate is called upon active paint operations then result could be null. But Locate and paint process are using the same vector enumerator context.
It is recommended to check InPaint property before calling this Locate.