Geometry Service Buffer method
Buffers an array of geometries by each distance
specified in an array of distances. Geometries
buffered at a given distance can optionally be unioned together.
Buffer(SpatialReference
InSpatialReference, SpatialReference BufferSpatialReference,
SpatialReference OutSpatialReference, double[] Distances, Unit Unit, boolean
UnionResults, Geometry[] InGeometryArray)
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Parameter |
Description |
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InSpatialReference |
SpatialReference of the geometries in the InGeometryArray.
Cannot be null.
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BufferSpatialReference |
The SpatialReference in which the geometries
are buffered. Can be null.
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OutSpatialReference |
SpatialReference of the geometry returned from
the buffer operation. Can be null.
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Distances |
An array of double values. Each
value specifies a distance to buffer the input geometries.
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Unit |
The units for each distance specified in the
Distances array.
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UnionResults |
If false, each buffer polygon will be added
to the output Geometry array separately. If
true, then all geometries buffered at a given distance will be unioned
into a single (possibly multi-part) polygon and included in the output
Geometry array.
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InGeometryArray |
The array of Geometry to be buffered by each
distance in the array Distances. All geometries are assumed to be in the
coordinate system InSpatialReference.
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Return Value
An array of Geometry (Geometry[])
of type Polygon.
Remarks
Either
or both the BufferSpatialReference and OutSpatialReference can be null.
If one is not null, the one defined is used for
both buffering and output. If the spatial
reference is the same, the distances can still be specified in a separate
unit of measure - defined by the Unit parameter to the method. For
example, the buffer distances can be specified in feet and the coordinates
of the output geometries can be specified in meters, although both the
buffer and output geometry share the same spatial reference.
The SpatialReference property for all returned geometry will be null. It
is the consumers responsibility to assign the spatial reference to each
geometry returned, if desired. In this case, the
spatial reference is assumed to be the output spatial reference defined
for the Buffer operation.
True ground distance buffering (i.e. "geodesic" buffering) in
a geographic coordinate system is only supported for point and multipoint
features. In order to meaningfully buffer polylines
and polygons defined in a geographic coordinate system, you need to specify
a planar (projected) coordinate system in which the buffering will happen.
Use the BufferSpatialReference parameter to define
this coordinate system. When the Buffer method
is called, the input features will be projected into this coordinate system
(BufferSpatialReference), buffered, and then either inverse projected
into the original coordinate system (InSpatialReference) or projected
into the output coordinate system (OutSpatialReference).
Examples