A Shapefile Point Shape
Наследование: Shape
Пример #1
0
        /// <summary>
        /// Creates a Shape object (or derived object) from a shape record
        /// </summary>
        /// <param name="shapeData">The shape record as a byte array</param>
        /// <param name="metadata">Metadata associated with this shape (optional)</param>
        /// <param name="dataRecord">IDataRecord associated with the metadata</param>
        /// <returns>A Shape, or derived class</returns>
        /// <exception cref="ArgumentNullException">Thrown if shapeData or metadata are null</exception>
        /// <exception cref="ArgumentException">Thrown if shapeData is less than 12 bytes long</exception>
        /// <exception cref="InvalidOperationException">Thrown if an error occurs parsing shapeData</exception>
        public static Shape ParseShape(byte[] shapeData, StringDictionary metadata, IDataRecord dataRecord)
        {
            if (shapeData == null)
            {
                throw new ArgumentNullException("shapeData");
            }

            if (shapeData.Length < 12)
            {
                throw new ArgumentException("shapeData must be at least 12 bytes long");
            }

            // shape data contains a header (shape number and content length)
            // the first field in each shape is the shape type

            //Position  Field           Value                   Type        Order
            //Byte 0    Record          Number Record Number    Integer     Big
            //Byte 4    Content Length  Content Length          Integer     Big

            //Position  Field       Value                   Type        Number      Order
            //Byte 0    Shape Type  Shape Type              Integer     1           Little

            int       recordNumber         = EndianBitConverter.ToInt32(shapeData, 0, ProvidedOrder.Big);
            int       contentLengthInWords = EndianBitConverter.ToInt32(shapeData, 4, ProvidedOrder.Big);
            ShapeType shapeType            = (ShapeType)EndianBitConverter.ToInt32(shapeData, 8, ProvidedOrder.Little);

            // test that we have the expected amount of data - need to take the 8 byte header into account
            if (shapeData.Length != (contentLengthInWords * 2) + 8)
            {
                throw new InvalidOperationException("Shape data length does not match shape header length");
            }

            Shape shape = null;

            switch (shapeType)
            {
            case ShapeType.Null:
                shape = new Shape(shapeType, recordNumber, metadata, dataRecord);
                break;

            case ShapeType.Point:
                shape = new ShapePoint(recordNumber, metadata, dataRecord, shapeData);
                break;

            case ShapeType.MultiPoint:
                shape = new ShapeMultiPoint(recordNumber, metadata, dataRecord, shapeData);
                break;

            case ShapeType.PolyLine:
                shape = new ShapePolyLine(recordNumber, metadata, dataRecord, shapeData);
                break;

            case ShapeType.PolyLineM:
                shape = new ShapePolyLineM(recordNumber, metadata, dataRecord, shapeData);
                break;

            case ShapeType.Polygon:
                shape = new ShapePolygon(recordNumber, metadata, dataRecord, shapeData);
                break;

            default:
                throw new NotImplementedException(string.Format("Shapetype {0} is not implemented", shapeType));
            }

            return(shape);
        }
Пример #2
0
        /// <summary>
        /// Creates a Shape object (or derived object) from a shape record
        /// </summary>
        /// <param name="shapeData">The shape record as a byte array</param>
        /// <param name="metadata">Metadata associated with this shape (optional)</param>
        /// <param name="dataRecord">IDataRecord associated with the metadata</param>
        /// <returns>A Shape, or derived class</returns>
        /// <exception cref="ArgumentNullException">Thrown if shapeData or metadata are null</exception>
        /// <exception cref="ArgumentException">Thrown if shapeData is less than 12 bytes long</exception>
        /// <exception cref="InvalidOperationException">Thrown if an error occurs parsing shapeData</exception>
        public static Shape ParseShape(byte[] shapeData, StringDictionary metadata, IDataRecord dataRecord)
        {
            if (shapeData == null)
            {
                throw new ArgumentNullException("shapeData");
            }

            if (shapeData.Length < 12)
            {
                throw new ArgumentException("shapeData must be at least 12 bytes long");
            }

            // shape data contains a header (shape number and content length)
            // the first field in each shape is the shape type

            //Position  Field           Value                   Type        Order
            //Byte 0    Record          Number Record Number    Integer     Big
            //Byte 4    Content Length  Content Length          Integer     Big

            //Position  Field       Value                   Type        Number      Order
            //Byte 0    Shape Type  Shape Type              Integer     1           Little

            int recordNumber = EndianBitConverter.ToInt32(shapeData, 0, ProvidedOrder.Big);
            int contentLengthInWords = EndianBitConverter.ToInt32(shapeData, 4, ProvidedOrder.Big);
            ShapeType shapeType = (ShapeType)EndianBitConverter.ToInt32(shapeData, 8, ProvidedOrder.Little);

            // test that we have the expected amount of data - need to take the 8 byte header into account
            if (shapeData.Length != (contentLengthInWords * 2) + 8)
            {
                throw new InvalidOperationException("Shape data length does not match shape header length");
            }

            Shape shape = null;

            switch (shapeType)
            {
                case ShapeType.Null:
                    shape = new Shape(shapeType, recordNumber, metadata, dataRecord);
                    break;

                case ShapeType.Point:
                    shape = new ShapePoint(recordNumber, metadata, dataRecord, shapeData);
                    break;

                case ShapeType.MultiPoint:
                    shape = new ShapeMultiPoint(recordNumber, metadata, dataRecord, shapeData);
                    break;

                case ShapeType.PolyLine:
                    shape = new ShapePolyLine(recordNumber, metadata, dataRecord, shapeData);
                    break;

                case ShapeType.PolyLineM:
                    shape = new ShapePolyLineM(recordNumber, metadata, dataRecord, shapeData);
                    break;

                case ShapeType.Polygon:
                    shape = new ShapePolygon(recordNumber, metadata, dataRecord, shapeData);
                    break;

                case ShapeType.PolygonZ:
                    shape = new ShapePolygonZ(recordNumber, metadata, dataRecord, shapeData);
                    break;

                default:
                    throw new NotImplementedException(string.Format("Shapetype {0} is not implemented", shapeType));
            }

            return shape;
        }