SqlGeography.BufferWithTolerance 方法
Returns a geometric object representing the union of all point values whose distance from a SqlGeography instance is less than or equal to a specified value, allowing for a specified tolerance.
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 BufferWithTolerance ( _
distance As Double, _
tolerance As Double, _
relative As Boolean _
) As SqlGeography
'用途
Dim instance As SqlGeography
Dim distance As Double
Dim tolerance As Double
Dim relative As Boolean
Dim returnValue As SqlGeography
returnValue = instance.BufferWithTolerance(distance, _
tolerance, relative)
[SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)]
public SqlGeography BufferWithTolerance(
double distance,
double tolerance,
bool relative
)
[SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)]
public:
SqlGeography^ BufferWithTolerance(
double distance,
double tolerance,
bool relative
)
[<SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)>]
member BufferWithTolerance :
distance:float *
tolerance:float *
relative:bool -> SqlGeography
public function BufferWithTolerance(
distance : double,
tolerance : double,
relative : boolean
) : SqlGeography
參數
- distance
型別：System.Double
Is a double that specifies the distance from the SqlGeography instance around which to calculate the buffer.
- tolerance
型別：System.Double
Is a double that specifies the tolerance of the buffer distance.The tolerance value refers to the maximum variation in the ideal buffer distance for the returned linear approximation.For example, the ideal buffer distance of a point is a circle, but this must be approximated by a polygon. The smaller the tolerance, the more points the polygon will have, which increases the complexity of the result, but decreases the error.
- relative
型別：System.Boolean
Is a bool that specifies whether the tolerance value is relative or absolute. If true, then tolerance is relative and is calculated as the product of the tolerance parameter and the angular extent * equatorial radius of the ellipsoid. If false, tolerance is absolute and the tolerance value is the absolute maximum variation in the ideal buffer distance for the returned linear approximation.
傳回值
型別：Microsoft.SqlServer.Types.SqlGeography
A SqlGeography instance representing the union of all point values whose distance from a SqlGeography instance is less than or equal to a specified value.
備註
A negative buffer removes all points within the given distance of the boundary of the SqlGeography instance.