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api:dk11:delphi:gislayervector.tgis_layervector.centroidscope_string_tgis_point

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TGIS_LayerVector.CentroidScope method

DK11 for Delphi | GisLayerVector.TGIS_LayerVector.CentroidScope | Constructors | Fields | Methods | Properties | Events

Calculates a centroid for a scope.

Available also on: .NET | Java | ActiveX.

Syntax

// Delphi
public
  function CentroidScope(
    const _query : String;
    const _centroid : TGIS_Point
  ) : TGIS_Point;
// C++ Builder
public:
  TGIS_Point* CentroidScope(
    const UnicodeString _query,
    TGIS_Point* const _centroid
  );

Parameters

Name Type Description
_query String Query closely mimics the SQL WHERE clause
_centroid TGIS_Point Current centroid - to be returned if not found

Result

Type Description
TGIS_Point Found centroid or untouched _centroid value.

Remarks

Use this method to calculate a centroid for a scope. It, in fact, finds the centroid for the first shape.

When using this operation, never call any function which uses FindFirst..FindNext (i.e., any function which iterates through the shapes using it). So never use it inside an operation like Locate, PaintScope, etc.

2020/05/07 01:09