/// <summary>
/// Reads and validates the header block from the map file.
/// </summary>
/// <param name="readBuffer">
/// the ReadBuffer for the file data. </param>
/// <param name="fileSize">
/// the size of the map file in bytes. </param>
/// <exception cref="IOException">
/// if an error occurs while reading the file. </exception>
public virtual void ReadHeader(ReadBuffer readBuffer, long fileSize)
{
RequiredFields.ReadMagicByte(readBuffer);
RequiredFields.ReadRemainingHeader(readBuffer);
MapFileInfoBuilder mapFileInfoBuilder = new MapFileInfoBuilder();
RequiredFields.ReadFileVersion(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadFileSize(readBuffer, fileSize, mapFileInfoBuilder);
RequiredFields.ReadMapDate(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadBoundingBox(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadTilePixelSize(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadProjectionName(readBuffer, mapFileInfoBuilder);
OptionalFields.ReadOptionalFields(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadPoiTags(readBuffer, mapFileInfoBuilder);
RequiredFields.ReadWayTags(readBuffer, mapFileInfoBuilder);
ReadSubFileParameters(readBuffer, fileSize, mapFileInfoBuilder);
this.mapFileInfo = mapFileInfoBuilder.Build();
}