private static void GetFieldDescriptorListFromSchema(DbfFile file)
{
//http://www.clicketyclick.dk/databases/xbase/format/data_types.html
file.FieldDescriptors = new List <DbfFile.FieldDescriptor>();
int fieldAddr = 1; //first is always 1
foreach (DataColumn col in file.DataTable.Columns)
{
DbfFile.FieldDescriptor fd = col.GetFieldDescriptor();
fd.FieldDataAddress = BitConverter.GetBytes(fieldAddr);
//FieldDataAddress is the index/offset of this field's data in a record, if the records were byte arrays
file.FieldDescriptors.Add(fd);
fieldAddr += fd.FieldLength; //sum each previous column's ByteLength, which equals the FieldLength
}
}
internal static DbfFile.FieldDescriptor GetFieldDescriptor(this DataColumn dc)
{
DbfFile.FieldDescriptor fd = new DbfFile.FieldDescriptor();
fd.FieldName = dc.ColumnName;
fd.FieldLength = dc.GetByteLength();
fd.DecimalCount = 0;
fd.WorkAreaId = 0;
fd.ReservedMultiUserOne = Enumerable.Repeat <byte>(0x0, 2).ToArray();
fd.ReservedMultiUserTwo = Enumerable.Repeat <byte>(0x0, 2).ToArray();
fd.FlagSetFields = 0;
fd.Reserved = Enumerable.Repeat <byte>(0x0, 7).ToArray();
fd.IndexFieldFlag = 0;
if (dc.DataType == typeof(string))
{
fd.FieldType = 'C';
}
else if (dc.DataType == typeof(long))
{
fd.FieldType = 'N'; //int64 (up to 18 chars according to dBase spec)
}
else if (dc.DataType == typeof(bool)) //nullable bool, byte
{
fd.FieldType = 'L';
}
else if (dc.DataType == typeof(double)) //double (8 bytes)
{
fd.FieldType = 'O';
}
//else if (this.DataType == typeof(dBaseShortDate)) //YYYYMMDD
// fd.FieldType = 'D';
//else if (this.DataType == typeof(dBaseTimestamp)) //long1 = days since 1-Jan-4713 BC, long2 = hrs * 3600000 + min * 60000 + sec * 1000
// fd.FieldType = '@';
//else if (this.DataType == typeof(dbaseAutoIncrement)) //auto-increment (long)
// fd.FieldType = '+';
else
{
throw new Exception($"Unknown column type: \'{dc.ColumnName}\' is {dc.DataType.ToString()}");
}
return(fd);
}
internal static DbfFile.FieldDescriptor GetFieldDescriptor(this DataColumn dc)
{
DbfFile.FieldDescriptor fd = new DbfFile.FieldDescriptor();
fd.FieldName = dc.ColumnName;
fd.FieldLength = dc.GetByteLength();
fd.DecimalCount = 0;
fd.WorkAreaId = 0;
fd.ReservedMultiUserOne = Enumerable.Repeat<byte>(0x0, 2).ToArray();
fd.ReservedMultiUserTwo = Enumerable.Repeat<byte>(0x0, 2).ToArray();
fd.FlagSetFields = 0;
fd.Reserved = Enumerable.Repeat<byte>(0x0, 7).ToArray();
fd.IndexFieldFlag = 0;
if (dc.DataType == typeof(string))
{
fd.FieldType = 'C';
}
else if (dc.DataType == typeof(long))
{
fd.FieldType = 'N'; //int64 (up to 18 chars according to dBase spec)
}
else if (dc.DataType == typeof(bool)) //nullable bool, byte
fd.FieldType = 'L';
else if (dc.DataType == typeof(double)) //double (8 bytes)
fd.FieldType = 'O';
//else if (this.DataType == typeof(dBaseShortDate)) //YYYYMMDD
// fd.FieldType = 'D';
//else if (this.DataType == typeof(dBaseTimestamp)) //long1 = days since 1-Jan-4713 BC, long2 = hrs * 3600000 + min * 60000 + sec * 1000
// fd.FieldType = '@';
//else if (this.DataType == typeof(dbaseAutoIncrement)) //auto-increment (long)
// fd.FieldType = '+';
else
throw new Exception($"Unknown column type: \'{dc.ColumnName}\' is {dc.DataType.ToString()}");
return fd;
}
