public DataTable Query(Envelope extents)
{
DataTable table = this.GetDataTable();
ArrayList indexes = new ArrayList(_spatialIndex.query(extents).toArray());
// Sort the results so we can go through the files sequentially
indexes.Sort();
ShapeHandler handler = null;
switch (_type)
{
case ShapeType.Point:
handler = new PointHandler();
break;
case ShapeType.Arc:
handler = new MultiLineHandler();
break;
case ShapeType.Polygon:
handler = new PolygonHandler();
break;
}
using (BinaryReader dbfReader = new BinaryReader(File.OpenRead(Path.Combine(Path.GetDirectoryName(_path), Path.GetFileNameWithoutExtension(_path) + ".dbf"))))
using (BigEndianBinaryReader shpReader = new BigEndianBinaryReader(File.OpenRead(_path)))
{
foreach (ShapefileRecordPointer pointer in indexes)
{
ArrayList record = new ArrayList();
// Step 1: Get the geometry
// NOTE: We add 8 here to skip the content length and record numer - we
// already have that information in the pointer object.
shpReader.BaseStream.Position = pointer.GeometryOffset + 8;
record.Add(handler.Read(shpReader, _factory));
// Step 2: Get the attributes
dbfReader.BaseStream.Position = pointer.AttributesOffset;
record.AddRange(DbaseFileReader.ReadRecord(dbfReader, _dbfHeader));
table.Rows.Add(record.ToArray());
}
}
return(table);
}
/// <summary>
/// Read a single dbase record
/// </summary>
/// <returns>return the read shapefile record or null if there are no more records</returns>
private ArrayList Read()
{
return(DbaseFileReader.ReadRecord(_dbfStream, _header));
}