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
Mostrar archivo Open project: jumpinjackie/fdotoolbox Class Usage Examples

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