/// <summary> /// Read a shapefile Polygon record. /// </summary> /// <param name="stream">Input stream.</param> /// <param name="record">Shapefile record to be updated.</param> private static void ReadPolygon(Stream stream, ShapeFileRecord record) { // Bounding Box. record.XMin = ShapeFile.ReadDouble64_LE(stream); record.YMin = ShapeFile.ReadDouble64_LE(stream); record.XMax = ShapeFile.ReadDouble64_LE(stream); record.YMax = ShapeFile.ReadDouble64_LE(stream); // Num Parts and Points. int numParts = ShapeFile.ReadInt32_LE(stream); int numPoints = ShapeFile.ReadInt32_LE(stream); // Parts. for (int i = 0; i < numParts; i++) { record.Parts.Add(ShapeFile.ReadInt32_LE(stream)); } // Points. for (int i = 0; i < numPoints; i++) { Point p = new Point(); p.X = ShapeFile.ReadDouble64_LE(stream); p.Y = ShapeFile.ReadDouble64_LE(stream); record.Points.Add(p); } }
/// <summary> /// Read a shapefile record. /// </summary> /// <param name="stream">Input stream.</param> public ShapeFileRecord ReadShapeFileRecord(Stream stream) { ShapeFileRecord record = new ShapeFileRecord(); // Record Header. record.RecordNumber = ShapeFile.ReadInt32_BE(stream); record.ContentLength = ShapeFile.ReadInt32_BE(stream); // Shape Type. record.ShapeType = ShapeFile.ReadInt32_LE(stream); // Read the shape geometry, depending on its type. switch (record.ShapeType) { case ( int )ShapeType.NullShape: // Do nothing. break; case ( int )ShapeType.Point: ShapeFile.ReadPoint(stream, record); break; case ( int )ShapeType.PolyLine: // PolyLine has exact same structure as Polygon in shapefile. ShapeFile.ReadPolygon(stream, record); break; case ( int )ShapeType.Polygon: ShapeFile.ReadPolygon(stream, record); break; case ( int )ShapeType.Multipoint: ShapeFile.ReadMultipoint(stream, record); break; default: { string msg = String.Format(System.Globalization.CultureInfo.InvariantCulture, "ShapeType {0} is not supported.", ( int )record.ShapeType); throw new NotSupportedException(msg); } } // Add the record to our internal list. this.records.Add(record); return(record); }
/// <summary> /// Read the file header of the shapefile. /// </summary> /// <param name="stream">Input stream.</param> public void ReadShapeFileHeader(Stream stream) { // File Code. this.fileHeader.FileCode = ShapeFile.ReadInt32_BE(stream); if (this.fileHeader.FileCode != ShapeFile.expectedFileCode) { string msg = String.Format(System.Globalization.CultureInfo.InvariantCulture, "Invalid FileCode encountered. Expecting {0}.", ShapeFile.expectedFileCode); throw new NotSupportedException(msg); } // 5 unused values. ShapeFile.ReadInt32_BE(stream); ShapeFile.ReadInt32_BE(stream); ShapeFile.ReadInt32_BE(stream); ShapeFile.ReadInt32_BE(stream); ShapeFile.ReadInt32_BE(stream); // File Length. this.fileHeader.FileLength = ShapeFile.ReadInt32_BE(stream); // Version. this.fileHeader.Version = ShapeFile.ReadInt32_LE(stream); // Shape Type. this.fileHeader.ShapeType = ShapeFile.ReadInt32_LE(stream); // Bounding Box. this.fileHeader.XMin = ShapeFile.ReadDouble64_LE(stream); this.fileHeader.YMin = ShapeFile.ReadDouble64_LE(stream); this.fileHeader.XMax = ShapeFile.ReadDouble64_LE(stream); this.fileHeader.YMax = ShapeFile.ReadDouble64_LE(stream); // Adjust the bounding box in case it is too small. if (Math.Abs(this.fileHeader.XMax - this.fileHeader.XMin) < 1) { this.fileHeader.XMin -= 5; this.fileHeader.XMax += 5; } if (Math.Abs(this.fileHeader.YMax - this.fileHeader.YMin) < 1) { this.fileHeader.YMin -= 5; this.fileHeader.YMax += 5; } // Skip the rest of the file header. stream.Seek(100, SeekOrigin.Begin); }