/// <summary>
/// Parses the first 100 bytes of a shapefile into the important values
/// </summary>
/// <param name="inFilename">The fileName to read</param>
public void Open(string inFilename)
{
_fileName = inFilename;
// Position Field Value Type ByteOrder
// --------------------------------------------------------------
// Byte 0 File Code 9994 Integer Big
// Byte 4 Unused 0 Integer Big
// Byte 8 Unused 0 Integer Big
// Byte 12 Unused 0 Integer Big
// Byte 16 Unused 0 Integer Big
// Byte 20 Unused 0 Integer Big
// Byte 24 File Length File Length Integer Big
// Byte 28 Version 1000 Integer Little
// Byte 32 Shape Type Shape Type Integer Little
// Byte 36 Bounding Box Xmin Double Little
// Byte 44 Bounding Box Ymin Double Little
// Byte 52 Bounding Box Xmax Double Little
// Byte 60 Bounding Box Ymax Double Little
// Byte 68 Bounding Box Zmin Double Little
// Byte 76 Bounding Box Zmax Double Little
// Byte 84 Bounding Box Mmin Double Little
// Byte 92 Bounding Box Mmax Double Little
// This may throw an IOException if the file is already in use.
BufferedBinaryReader bbReader = new BufferedBinaryReader(inFilename);
bbReader.FillBuffer(100); // we only need to read 100 bytes from the header.
bbReader.Close(); // Close the internal readers connected to the file, but don't close the file itself.
// Reading BigEndian simply requires us to reverse the byte order.
_fileCode = bbReader.ReadInt32(false);
// Skip the next 20 bytes because they are unused
bbReader.Seek(20, SeekOrigin.Current);
// Read the file length in reverse sequence
_fileLength = bbReader.ReadInt32(false);
// From this point on, all the header values are in little Endean
// Read the version
_version = bbReader.ReadInt32();
// Read in the shape type that should be the shape type for the whole shapefile
_shapeType = (ShapeType)bbReader.ReadInt32();
// Get the extents, each of which are double values.
_xMin = bbReader.ReadDouble();
_yMin = bbReader.ReadDouble();
_xMax = bbReader.ReadDouble();
_yMax = bbReader.ReadDouble();
_zMin = bbReader.ReadDouble();
_zMax = bbReader.ReadDouble();
_mMin = bbReader.ReadDouble();
_mMax = bbReader.ReadDouble();
bbReader.Dispose();
string shxFile = Path.ChangeExtension(Filename, ".shx");
FileInfo fi = new FileInfo(shxFile);
if (fi.Exists)
{
_shxLength = Convert.ToInt32(fi.Length / 2); //length is in 16 bit words.
}
}
/// <summary>
/// Parses the first 100 bytes of a shapefile into the important values
/// </summary>
/// <param name="inFilename">The fileName to read</param>
public void Open(string inFilename)
{
Filename = inFilename;
// Position Field Value Type ByteOrder
// --------------------------------------------------------------
// Byte 0 File Code 9994 Integer Big
// Byte 4 Unused 0 Integer Big
// Byte 8 Unused 0 Integer Big
// Byte 12 Unused 0 Integer Big
// Byte 16 Unused 0 Integer Big
// Byte 20 Unused 0 Integer Big
// Byte 24 File Length File Length Integer Big
// Byte 28 Version 1000 Integer Little
// Byte 32 Shape Type Shape Type Integer Little
// Byte 36 Bounding Box Xmin Double Little
// Byte 44 Bounding Box Ymin Double Little
// Byte 52 Bounding Box Xmax Double Little
// Byte 60 Bounding Box Ymax Double Little
// Byte 68 Bounding Box Zmin Double Little
// Byte 76 Bounding Box Zmax Double Little
// Byte 84 Bounding Box Mmin Double Little
// Byte 92 Bounding Box Mmax Double Little
// This may throw an IOException if the file is already in use.
BufferedBinaryReader bbReader = new BufferedBinaryReader(Filename);
bbReader.FillBuffer(100); // we only need to read 100 bytes from the header.
bbReader.Close(); // Close the internal readers connected to the file, but don't close the file itself.
// Reading BigEndian simply requires us to reverse the byte order.
FileCode = bbReader.ReadInt32(false);
// Skip the next 20 bytes because they are unused
bbReader.Seek(20, SeekOrigin.Current);
// Read the file length in reverse sequence
FileLength = bbReader.ReadInt32(false);
// From this point on, all the header values are in little Endean
// Read the version
Version = bbReader.ReadInt32();
// Read in the shape type that should be the shape type for the whole shapefile
ShapeType = (ShapeType)bbReader.ReadInt32();
// Get the extents, each of which are double values.
Xmin = bbReader.ReadDouble();
Ymin = bbReader.ReadDouble();
Xmax = bbReader.ReadDouble();
Ymax = bbReader.ReadDouble();
Zmin = bbReader.ReadDouble();
Zmax = bbReader.ReadDouble();
Mmin = bbReader.ReadDouble();
Mmax = bbReader.ReadDouble();
bbReader.Dispose();
FileInfo fi = new FileInfo(ShxFilename);
if (fi.Exists)
{
ShxLength = Convert.ToInt32(fi.Length / 2); // length is in 16 bit words.
}
}
