SqlGeography.EnvelopeCenter 方法
Returns a point that can be used as the center of a bounding circle for the geography instance.
命名空間： Microsoft.SqlServer.Types
組件： Microsoft.SqlServer.Types (在 Microsoft.SqlServer.Types.dll 中)
語法
'宣告
<SqlMethodAttribute(IsDeterministic := True, IsPrecise := False)> _
Public Function EnvelopeCenter As SqlGeography
'用途
Dim instance As SqlGeography
Dim returnValue As SqlGeography
returnValue = instance.EnvelopeCenter()
[SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)]
public SqlGeography EnvelopeCenter()
[SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)]
public:
SqlGeography^ EnvelopeCenter()
[<SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)>]
member EnvelopeCenter : unit -> SqlGeography
public function EnvelopeCenter() : SqlGeography
傳回值
型別：Microsoft.SqlServer.Types.SqlGeography
A SqlGeography value that specifies the location of the center of a bounding circle.
備註
To determine the bounding circle, each point in the instance is described as a vector from the center of the Earth to the point on the Earth's surface. The center point of the bounding circle is calculated by averaging all of the vectors. For closed loops, either in a polygon instance or a linestring instance, the first and last point is used only once.
This method returns a point. When used with EnvelopeAngle, the EnvelopeCenter method returns a bounding circle of a SqlGeography instance.
The EnvelopeCenter method returns a bounding circle for a SqlGeography instance, but the results are not guaranteed to produce the minimal bounding circle. In contrast, the SqlGeometry data type method STEnvelope is guaranteed to return the minimum bounding box when it is applied to a SqlGeometry instance.