C# Class SharpMap.Data.Providers.ShapeFile

Shapefile dataprovider

The ShapeFile provider is used for accessing ESRI ShapeFiles. The ShapeFile should at least contain the [filename].shp, [filename].idx, and if feature-data is to be used, also [filename].dbf file.

The first time the ShapeFile is accessed, SharpMap will automatically create a spatial index of the shp-file, and save it as [filename].shp.sidx. If you change or update the contents of the .shp file, delete the .sidx file to force SharpMap to rebuilt it. In web applications, the index will automatically be cached to memory for faster access, so to reload the index, you will need to restart the web application as well.

M and Z values in a shapefile is ignored by SharpMap.

Inheritance: SharpMap.Data.Providers.IProvider, IDisposable

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Public Methods

Method	Description
Close ( ) : void	Closes the datasource
Dispose ( ) : void	Disposes the object
ExecuteIntersectionQuery ( SharpMap geom, FeatureDataSet ds ) : void	Returns the data associated with all the geometries that are intersected by 'geom'. Please note that the ShapeFile provider currently doesn't fully support geometryintersection and thus only BoundingBox/BoundingBox querying are performed. The results are NOT guaranteed to lie withing 'geom'.
ExecuteIntersectionQuery ( SharpMap bbox, SharpMap ds ) : void	Returns all objects whose boundingbox intersects bbox. Please note that this method doesn't guarantee that the geometries returned actually intersect 'bbox', but only that their boundingbox intersects 'bbox'.
GetExtents ( ) : SharpMap.Geometries.BoundingBox	Returns the extents of the datasource
GetFeature ( uint RowID ) : SharpMap.Data.FeatureDataRow	Gets a datarow from the datasource at the specified index
GetFeature ( uint RowID, FeatureDataTable dt ) : SharpMap.Data.FeatureDataRow	Gets a datarow from the datasource at the specified index belonging to the specified datatable
GetFeatureCount ( ) : int	Returns the total number of features in the datasource (without any filter applied)
GetGeometriesInView ( SharpMap bbox ) : List	Returns geometries whose bounding box intersects 'bbox' Please note that this method doesn't guarantee that the geometries returned actually intersect 'bbox', but only that their boundingbox intersects 'bbox'. This method is much faster than the QueryFeatures method, because intersection tests are performed on objects simplifed by their boundingbox, and using the Spatial Index.
GetGeometryByID ( uint oid ) : SharpMap.Geometries.Geometry	Returns the geometry corresponding to the Object ID
GetObjectIDsInView ( SharpMap bbox ) : List	Returns geometry Object IDs whose bounding box intersects 'bbox'
GetXYTolerance ( ) : double?
Open ( ) : void	Opens the datasource
RebuildSpatialIndex ( ) : void	Forces a rebuild of the spatial index. If the instance of the ShapeFile provider uses a file-based index the file is rewritten to disk.
ShapeFile ( string filename ) : System	Initializes a ShapeFile DataProvider without a file-based spatial index.
ShapeFile ( string filename, bool fileBasedIndex ) : System	Initializes a ShapeFile DataProvider. If FileBasedIndex is true, the spatial index will be read from a local copy. If it doesn't exist, it will be generated and saved to [filename] + '.sidx'. Using a file-based index is especially recommended for ASP.NET applications which will speed up start-up time when the cache has been emptied.

Private Methods

Method	Description
CreateSpatialIndex ( string filename ) : Utilities.SpatialIndexing.QuadTree	Generates a spatial index for a specified shape file.
CreateSpatialIndexFromFile ( string filename ) : Utilities.SpatialIndexing.QuadTree	Loads a spatial index from a file. If it doesn't exist, one is created and saved
Dispose ( bool disposing ) : void
GetAllFeatureBoundingBoxes ( ) : List	Reads all boundingboxes of features in the shapefile. This is used for spatial indexing.
GetShapeIndex ( uint n ) : int	Gets the file position of the n'th shape
InitializeShape ( string filename, bool FileBasedIndex ) : void
LoadSpatialIndex ( ) : void
LoadSpatialIndex ( bool LoadFromFile ) : void
LoadSpatialIndex ( bool ForceRebuild, bool LoadFromFile ) : void
ParseHeader ( ) : void	Reads and parses the header of the .shx index file
ParseProjection ( ) : void	Reads and parses the projection if a projection file exists
ReadGeometry ( uint oid ) : SharpMap.Geometries.Geometry	Reads and parses the geometry with ID 'oid' from the ShapeFile Filtering is not applied to this method
ReadIndex ( ) : int[]	Reads the record offsets from the .shx index file and returns the information in an array
SwapByteOrder ( int i ) : int	Swaps the byte order of an int32

Method Details

Close() public method

Closes the datasource

public Close ( ) : void
return	void

Dispose() public method

Disposes the object

public Dispose ( ) : void
return	void

ExecuteIntersectionQuery() public method

Returns the data associated with all the geometries that are intersected by 'geom'. Please note that the ShapeFile provider currently doesn't fully support geometryintersection and thus only BoundingBox/BoundingBox querying are performed. The results are NOT guaranteed to lie withing 'geom'.

public ExecuteIntersectionQuery ( SharpMap geom, FeatureDataSet ds ) : void
geom	SharpMap
ds	FeatureDataSet	FeatureDataSet to fill data into
return	void

ExecuteIntersectionQuery() public method

Returns all objects whose boundingbox intersects bbox.

Please note that this method doesn't guarantee that the geometries returned actually intersect 'bbox', but only that their boundingbox intersects 'bbox'.

public ExecuteIntersectionQuery ( SharpMap bbox, SharpMap ds ) : void
bbox	SharpMap
ds	SharpMap
return	void

GetExtents() public method

Returns the extents of the datasource

public GetExtents ( ) : SharpMap.Geometries.BoundingBox
return	SharpMap.Geometries.BoundingBox

GetFeature() public method

Gets a datarow from the datasource at the specified index

public GetFeature ( uint RowID ) : SharpMap.Data.FeatureDataRow
RowID	uint
return	SharpMap.Data.FeatureDataRow

GetFeature() public method

Gets a datarow from the datasource at the specified index belonging to the specified datatable

public GetFeature ( uint RowID, FeatureDataTable dt ) : SharpMap.Data.FeatureDataRow
RowID	uint
dt	FeatureDataTable	Datatable to feature should belong to.
return	SharpMap.Data.FeatureDataRow

GetFeatureCount() public method

Returns the total number of features in the datasource (without any filter applied)

public GetFeatureCount ( ) : int
return	int

GetGeometriesInView() public method

Returns geometries whose bounding box intersects 'bbox'

Please note that this method doesn't guarantee that the geometries returned actually intersect 'bbox', but only that their boundingbox intersects 'bbox'.

This method is much faster than the QueryFeatures method, because intersection tests are performed on objects simplifed by their boundingbox, and using the Spatial Index.

public GetGeometriesInView ( SharpMap bbox ) : List
bbox	SharpMap
return	List

GetGeometryByID() public method

Returns the geometry corresponding to the Object ID

public GetGeometryByID ( uint oid ) : SharpMap.Geometries.Geometry
oid	uint	Object ID
return	SharpMap.Geometries.Geometry

GetObjectIDsInView() public method

Returns geometry Object IDs whose bounding box intersects 'bbox'

public GetObjectIDsInView ( SharpMap bbox ) : List
bbox	SharpMap
return	List

GetXYTolerance() public method

public GetXYTolerance ( ) : double?
return	double?

Open() public method

Opens the datasource

public Open ( ) : void
return	void

RebuildSpatialIndex() public method

Forces a rebuild of the spatial index. If the instance of the ShapeFile provider uses a file-based index the file is rewritten to disk.

public RebuildSpatialIndex ( ) : void
return	void

ShapeFile() public method

Initializes a ShapeFile DataProvider without a file-based spatial index.

public ShapeFile ( string filename ) : System
filename	string	Path to shape file
return	System

ShapeFile() public method

Initializes a ShapeFile DataProvider.

If FileBasedIndex is true, the spatial index will be read from a local copy. If it doesn't exist, it will be generated and saved to [filename] + '.sidx'.

Using a file-based index is especially recommended for ASP.NET applications which will speed up start-up time when the cache has been emptied.

public ShapeFile ( string filename, bool fileBasedIndex ) : System
filename	string	Path to shape file
fileBasedIndex	bool	Use file-based spatial index
return	System